Abstract
Background
Personality traits may influence development and adjustment to ongoing pain. Over the past 120 years, there has been considerable research into the relationship between pain and personality. This paper presents new evidence for common personality traits found amongst chronic pain sufferers. In particular, it evaluates evidence for Cloninger’s biopsychosocial model of personality in distinguishing typical personality features of chronic pain sufferers. It evaluates this evidence in the context of the past 120 years of research including psychodynamic formulations, MMPI studies, personality disorder investigations, and the influence of neuroticism on chronic pain.
Methods
A literature search was conducted using PubMed, Medline, PsyclNFO, SCOPUS and Cochrane library. Search terms included chronic pain, pain, personality, neuroticism, harm avoidance, self-directedness, attachment, Temperament and Character Inventory (TCI-R), MMPI, MMPI-2, NEO-PI, EPI, Millon Clinical Multiaxial Inventory, Millon Behavioral Health Inventory, Millon Behavioral Medicine Diagnostic, the Personality Assessment Inventory, the Locus of Control Construct and different combinations of these terms.
Conclusions
Recent descriptive studies using Cloninger’s Temperament and Character Inventory (TCI-R) suggest that higher harm avoidance and lower self-directedness may be the most distinguishing personality features of chronic pain sufferers. High harm avoidance refers to a tendency to be fearful, pessimistic, sensitive to criticism, and requiring high levels of re-assurance. Low self-directedness often manifests as difficulty with defining and setting meaningful goals, low motivation, and problems with adaptive coping. Evidence for this personality profile is found across a wide variety of chronic pain conditions including fibromyalgia, headache and migraine, temporomandibular disorder, trigeminal neuropathy, musculo-skeletal disorders and heterogeneous pain groups. Limitations are also discussed. For example, high harm avoidance is also found in those suffering anxiety and depression. While many studies control for such factors, some do not and thus future research should address such confounds carefully. The evidence is also evaluated within the context of past research into the existence of ‘a pain personality’. Psychodynamic formulations are found to be deficient in objective scientific methods. MMPI studies lack sufficient evidence to support ‘a pain personality’ and may be confounded by somatic items in the instrument. More recent neuroticism studies suggest a relationship between neuroticism and pain, particularly for adjustment to chronic pain. Personality disorders are more prevalent in chronic pain populations than non-pain samples.
Clinical implications
Because harm avoidance reflects a tendency to developed conditioned fear responses, we suggest that higher harm avoidance may create more vulnerability to developing a fear-avoidance response to chronic pain. Furthermore, lower self-directedness may contribute to keeping a sufferer within this vicious cycle of fear, avoidance and suffering. Moreover, we suggest that harm avoidance and self-directedness are broader and more complex constructs than current clinical targets of CBT such as fear-avoidance and self-efficacy. Thus, assessing such personality traits may help to address the complexity of chronic pain presentations. For example, it may help to identify and treat sufferers more resistant to treatment, more prone to comorbidity and more vulnerable to entering the vicious cycle of chronic pain, suffering and disability.
1 Introduction
Reflections from Karen,[1] a chronic pain sufferer:
“I often get told that I’ve changed since I developed chronic pain. It makes me really sad. I’m afraid that the pain will never go away. I don’t want to visit my friends anymore. It’s so depressing when you visit friends with so much pain – I can’t laugh when they’re all laughing. Yes, I think my friends are right. I’m a different person to who I was before I had pain. My husband says that I might even have developed it because I’ve always been such a fearful person. I wonder if it might actually be part of my personality, and I’m afraid that it will never go away”.
Chronic pain is a complex phenomenon, generally recognised as involving psychological as well as physical dimensions. Specifically, it is conceptualised as multidimensional with not only sensory but also cognitive, affective, and social components [1]. Evidence is arising that people with different chronic pain types (neuropathic, nociceptive and inflammatory) share similar pain experiences of affective-motivational, cognitive-evaluative and social components, despite sensory-discriminative differences [2,3,4]. Therefore, if there are common psychosocial states associated with chronic pain, independent of chronic pain type, could there also be typical personality traits underlying chronic pain? Indeed, many clinicians note anecdotally that chronic pain sufferers often present with personality and interpersonal issues [5]. Research findings also suggest that chronic pain sufferers display elevated levels of anxiety and depression [6] and personality disorders [7].
Personality traits are ‘enduring patterns of perceiving, relating to, and thinking about the environment and oneself that are displayed in a wide range of social and personal contexts’ [8]. Personality traits may be important to the understanding and treatment of chronic pain, as they maybe implicated in the development and adjustment to chronic pain [9,10]. While older studies could not confirm a typical pain personality, new evidence suggests that a pain personality independent of chronic pain type may exist.
2 Purpose and overview
This paper presents new evidence for common personality traits found amongst chronic pain sufferers. In particular, it evaluates Cloninger’s model of higher harm avoidance and lower self-directedness as distinguishing personality features of chronic pain. It evaluates this new evidence in the context of the past 120 years of research into the question of the relationship between personality and pain. Moreover, potential clinical implications of these personality traits for chronic pain development and maintenance will be suggested.
3 Methods
A literature search for this critical review was conducted using PubMed, Medline, PsycINFO, SCOPUS and Cochrane library. Search terms included chronic pain, pain, personality, neuroticism, harm avoidance, self-directedness, attachment, Temperament and Character Inventory (TCI-R), MMPI, MMPI-2, NEO-PI, EPI, Millon Clinical Multiaxial Inventory, Millon Behavioral Health Inventory, Millon Behavioral Medicine Diagnostic, the Personality Assessment Inventory, the Locus of Control Construct and different combinations of these terms.
4 History of the relationship between pain and personality
While this paper focusses on the last 120 years, it is interesting to note that the link between personality and pain has been explored throughout the ages [11]. For example, during the stone age, Chinese medicine conceptualised pain as arising from problems with blood flow and ‘qi’ caused by imbalances between the physical and intra-personal opposites of yin and yang [12]. During the classical period, the ancient Greek physician Hippocrates proposed one of the first theories of personality by positing that four internal bodily fluids, or ‘humours’ were responsible for personality temperaments as well as specific physical and mental disorders. He believed that pain was due to an imbalance in one of these ‘humours’, which included blood, black bile, yellow bile and phlegm. Other Greek philosophers such as Plato and Aristotle believed that pain arose not only from physical stimuli but also from emotions in the soul and heart [13]. These ideas about pain and personality highlight the ancient holistic mind-body tradition that is now reflected in the modern biopsychosocial model of medicine.
4.1 The psychodynamic approach
Since the 19th century, the link between personality factors and the pain experience has been explored, often due to the failure of the biomedical model of health to explain persistent pain without clear biological cause [14]. This is because the biomedical model of health focussed purely on biological factors and excluded psychological, environmental and social influences [10].
Early research focussed on personality as a causal factor for chronic pain. For example, the psychodynamic theorists, led by Freud, posited a conversion model of pain, whereby the sufferer ‘converted’ emotional pain to somatic symptoms due to underlying personality and emotional conflicts [15]. This basic premise influenced later psychoanalytical theorists such as Engel [16], who proposed the notion of a ‘pain-prone’ patient. Engel posited a ‘psychogenic pain’ theory to explain pain without apparent physical cause. According to Engel, early and lifelong associations with pain caused some individuals to use pain unconsciously to resolve conflicts and maintain emotional equilibrium. He suggested that from birth, a child built a ‘library’ of emotional associations with physical pain and that later these associations could be triggered without actual physical pain. For example, if a child experiences pain and cries, and is subsequently comforted by her mother, the pain becomes a cue for reunification with a love-object. Engel also suggested that this early conditioning developed into a ‘pain prone personality’ which was characterised by feelings of guilt, suffering, defeat, strong unfulfilled aggressive drives and loss, or fear of loss in relationships.
Building on these ideas, Blumer and Heilbronn posited a ‘pain-prone disorder’ which they characterised as a variant of’depressive disease’ for patients without clear organic cause for their pain [17]. They described these patients as expressing continuous pain complaints, having a pre-occupation with somatic symptoms, and displaying inactivity, anhedonia, alexithymia, despair and insomnia. Blumer and Heilbronn suggested that many of these symptoms were simply ‘masked depression’ and that sufferers transformed their depressive pain into physical pain as a means of coping with inner feelings of guilt, neediness and conflict about owning such feelings.
These psychodynamic perspectives were important because they suggested that psychological and personality factors played a role in chronic pain. However, the evidence for a ‘pain-prone patient’ was criticised as being unconvincing, based on anecdotal accounts, and possessing rudimentary scientific methods [18,19].
4.2 The trait theoretical approach
In direct contrast to rudimentary methods of the psychodynamic approach, trait theorists from the 1950s onwards attempted to find objective and scientifically measurable, personality traits in chronic pain sufferers. For this purpose, a variety of psychometric instruments were used including the Personality Assessment Inventory (PAI), the Millon Multiaxial and Health Inventories, the Locus of Control Construct, the Minnesota Multiphasic Personality Inventory (MMPI), the Eysenck Personality Inventory (EPI) and the Neuroticism, Extroversion and Openness Personality Inventory (NEO-PI) among others. While some inventories may be useful, particularly in predicting the patient coping styles which respond better to treatment, this review will focus primarily on MMPI, EPI and NEO-PI studies, as this research more directly addresses the question of a chronic pain personality profile. The MMPI was designed to assess psychopathology in clinical populations and the NEO-PI and EPI to measure non-clinical groups. Most studies focussed on a trait related to emotional reactivity and a tendency towards negative emotional states, although used different labels. For example, the MMPI labels this as ‘hypochondriasis, depression and hysteria’ whereas The EPI and NEO-PI using the term ‘neuroticism’.
4.2.1 MMPI descriptive studies
Early MMPI research tried to discriminate psychological from physical causes of chronic pain by identifying personality traits common to these different groups of sufferers [5]. For example, Hanvik [20] identified clinical elevations among a large number of chronic pain sufferers without a diagnosed physical cause on MMPI scales one to three. These scales measured hypochondriasis, depression and hysteria respectively. The scoring for depression tended to be slightly lower than hypochondriasis and hysteria, so this pattern was labelled the ‘conversion V’ pattern, or ‘neurotic triad’ due to its visual ‘V’ impression. These results were interpreted as support for the psychodynamic formulation of pain, whereby depressed individuals, unable to express their emotions, convert them into physical symptoms. A number of studies found support for a conversion ‘V’ pattern of scoring in a large group of chronic pain sufferers [21,22]; however, many researchers reported only the mean MMPI profile, perhaps over-interpreting these sufferers as one homogenous group [23]. Moreover, other studies found evidence of more than one personality profile of chronic pain sufferers using the MMPI [24,25,26,27,28]. This research raised questions about whether the conversion ‘V’ personality pattern on the MMPI was common for all chronic pain patients or whether there were subgroups of personality types.
One theorist to investigate the question of subgroups was Sternbach [28,29,30] who identified four common patterns of MMPI scoring for chronic pain sufferers, including the ‘conversion V’. The first group displayed clinical elevations on the scales for hysteria and hypochondriasis and were characterised as preoccupied with somatic concerns. The second group was labelled an ‘emotionally overwhelmed’ type, and displayed elevations on all of the first three subscales. Sternbach [29] concluded that these individuals suffered from depression and anxiety, perhaps due to somatic pain and were most responsive to treatment. The third subgroup displayed the conversion ‘V’ pattern, and the fourth subgroup displayed elevations on scale four, ‘psychopathic deviance’, as well as scales one to three. These patients were described as angry, manipulative and ‘acting out’ by using physical symptoms to get needs met. Sternbach [28] suggested that chronic pain sufferers suffered commonly from depression and a variety of neurotic disturbances characterised by pre-occupations with somatic symptoms.
Several other descriptive studies tried to replicate Sternbach’s MMPI sub-group findings. The ‘emotionally overwhelmed type’ and ‘conversion V’ were upheld, although other subgroups were not replicated [24,25,27]. Therefore, MMPI descriptive studies did not offer any consistent evidence of one chronic pain personality; rather, they suggested that there may be subgroups of personality profiles for some chronic pain sufferers [5].
4.2.2 MMPI prospective studies
Another approach to examining the relationship between pain and personality is to examine whether personality features are causal in the development of chronic pain. A small set of studies did this using prospective study designs. These studies attempted to tease out this relationship, by measuring the personality of healthy individuals with the MMPI and tracking the development of chronic pain over time [31,32,33,34]. One study [31] following 400 Danish men and women over 20 years found some support for greater incidence of pain in those scoring higher on hypochondriasis, hysteria and depression scales before pain onset. Another which tracked 3000 Boeing employees over four years found that those scoring in the upper quintile on the hysteria scale were more likely to develop lower back pain [34]. These studies, as well as producing inconsistent findings, also suffered from methodological flaws. For example, in one study [31], the physical status of participants was not recorded. Therefore, it was not possible to determine if higher MMPI scores were the result of an understandable focus on greater physical symptoms [31]. Moreover, adding to the complexity, other factors were also strong predictors of pain development such as gender, job dissatisfaction [34], filing of workers compensation claims, and initial scores on pain and disability measures [33].
In summary, evidence from MMPI studies between 1950 and 2000, appeared to support the notion of different MMPI personality profiles among varied chronic pain types. However, there was insufficient evidence to support a ‘pain-prone personality’, even though there was some evidence that a large proportion of chronic pain sufferers experienced emotional problems [6]. Many studies also had methodological flaws such as lack of control groups and confounding variables [14]. For example, the MMPI was criticised because many items use somatic symptoms to assess underlying neurotic traits [14,35]. Therefore, chronic pain sufferers may be responding more to physical symptoms of pain rather than to underlying neurotic problems. As a result, since the 1990s, there has been a dramatic decline in MMPI investigations of chronic pain populations [36], although the improved MMPI-2-has still been used to a lesser extent and the revised MMPI-2-RF was validated in a low back pain population recently [36].
4.2.3 Neuroticism and descriptive studies
Another line of inquiry from the trait perspective involves the role of non-pathological factors, namely the trait dimension ‘neu-roticism’, as measured by scales such as the NEO-PI [37] and EPI [38] (Eysenck Personality Inventory) and its relationship to chronic pain. Neuroticism reflects a person’s tendency to experience negative emotions such as anger, anxiety, irritability, depression and low self-esteem. Those high in neuroticism are more emotionally reactive and vulnerable to stress. They are also more likely to interpret ordinary situations as threatening and minor frustrations as hopelessly difficult. While the term neuroticism is problematic as it may seem pejorative for the layperson due to its common association with emotional instability and reactivity, it will be used in this review because this is the term used in the research. However, the authors note that neuroticism is a normal personality dimension that varies between individuals.
It is suggested that neuroticism is linked to a range of physical illnesses including chronic pain [39]. As a result, a number of descriptive studies have assessed if chronic pain sufferers display higher levels of neuroticism compared to control groups. A considerable number of studies have found this to be the case in various chronic pain types [40,41,42,43,44,45,46,47,48,49]. However, other studies have found relatively normal personality profiles, or only sub-groups of chronic pain sufferers with higher neuroticism [50,51,52,5354]. Unfortunately, many studies, particularly the older ones, suffer from the similar methodological flaws and lack of scientific methods found in early MMPI studies. As a result, evidence is inconclusive. Despite this, some recent studies supporting increased neuroticism present some interesting evidence due to larger, more representative samples, healthy control groups and sounder methods [45,55]. However, larger, more controlled studies are needed.
4.2.4 Neuroticism and prospective studies
Others have suggested that neuroticism may be a causal factor for chronic pain. Several theorists [39,56,57,58] have suggested that neuroticism is causally related to physical illness including chronic pain because it creates a greater physiological response to stress, which may contribute to changes associated with disease states. Another argument suggests that neuroticism pre-disposes individuals to lifestyle factors which may increase the risk of disease [59,60].
Several studies have tested this aetiological link using prospective study designs where a group of healthy individuals is tracked over time for pain development. For example, Pietri-Taleb et al. [61] followed 1015 machine operators, carpenters and office workers over three years. Higher neuroticism scores predicted the development of ‘severe neck trouble’ in the machine operator group. Similar results were found for headache in a group of 3676 adolescents [62] and migraine [56] among 972 female health workers However, these findings need to be interpreted with caution due to a small number of studies and lack of consistency in how pain was defined.
4.2.5 Neuroticism and adjustment to chronic pain
In contrast to the causal explanation of neuroticism’s role in chronic pain, since the 1980s, much research has focussed on neuroticism as a moderator of the pain experience [6]. The suggestion is that individuals with higher trait neuroticism may respond more poorly to pain than those with lower neuroticism, and as a result may be more likely to suffer more and exacerbate the pain experience. Because of this maladjustment, in terms of a ‘pain-personality’, heightened neuroticism may be one personality trait which leads acute pain to develop into chronic pain, or it may be one personality characteristics which develops after onset of chronic pain and compounds adjustment. Several mechanisms have been suggested to explain the influence of neuroticism on adjustment.
The first suggested mechanism is that neuroticism may create heightened physical sensitivity to pain due to its inherent connection with chronically moderated anxiety [47,63,64,65,66,67]. As a result, sufferers may be more likely to attend to their pain and bodily symptoms, thus leading to hypervigilance and amplification of symptoms, which are suggested cognitive-affective components in the development of chronic pain [68]. However, there are mixed results for reported pain intensity in chronic pain sufferers, with some studies finding higher reported pain intensity for more neurotic subjects and others finding no connection [69,70,71].
Another suggested mechanism is that neuroticism influences adjustment to pain by affecting pain-related beliefs and emotional distress. For example, Harkins et al. [71] investigated the relationship between neuroticism as measured by the EPI, and experimental and clinical pain intensity. When subjected to the same intensity of noxious stimulus, those with higher neuroticism scores reported greater emotional distress. In addition, Wade et al. [70] reported a relationship between neuroticism, heightened emotional distress and negative pain-related beliefs such as the ability to endure pain, reduce pain and confidence that the pain will be cured. Other studies have found similar results [69,72]. Limitations of some studies include a lack of psychometric properties for emotion and cognition measures, small sample sizes, and statistical problems. However, two methodologically sound longitudinal studies with rheumatoid arthritis sufferers also reported similar associations between neuroticism and negative mood in chronic pain sufferers [73].
The third suggested mechanism is that neuroticism leads to less-adaptive and passive coping strategies. Several studies have found a relationship between this trait and maladaptive coping skills including: relinquishing control over pain to another person; allowing pain to adversely affect other areas of life; less effective problem-solving; fewer cognitive restructuring strategies; greater use of emotional expression and fewer relaxation activities [44,74,75,76].
4.2.6 Neuroticism and the fear avoidance model of chronic pain
Another recent line of research has focussed on the link between neuroticism and components of the fear avoidance model of chronic pain. This model suggests that personality vulnerabilities may lead certain people to be more threatened by pain, thus resulting in greater pain-related fear, avoidance and disability [9]. Catastrophizing is a ruminative thinking style which tends to exaggerate negative responses to potential or actual pain. It is conceptualised as a pre-cursor to pain-related fear and avoidance and has been linked to more severe pain, psychological distress, impaired coping and increased disability [77]. Several studies have found that neuroticism may contribute to greater catastrophizing about pain [73,78]. Others have found that neuroticism indirectly affects pain-related anxiety through its influence on catastrophizing [42,77]. Goubert et al. [79] also found that neuroticism and vigilance to pain were related to pain catastrophizing and fear of movement re-injury. However, not all studies have found a relationship between neuroticism and catastrophizing [69].
Finally, anxiety sensitivity and injury/illness sensitivity, lower-order constructs of neuroticism and trait anxiety, have also been implicated in the fear avoidance model. Anxiety sensitivity refers to the tendency to react anxiously to one’s own anxiety and anxiety-related physical sensations. Injury/illness sensitivity refers to ‘fearfulness of imminent injury and illness’ [80]. A number of studies have found anxiety sensitivity to be positively correlated with pain-related anxiety among healthy [81] and chronic pain samples [82]. Higher anxiety sensitivity has also been found to be indirectly related to higher avoidance [83]. In a study by Vancleef et al. [80], injury/illness sensitivity was found to be more predictive of fear of pain, pain catastrophizing and anticipatory fear than anxiety sensitivity.
4.2.7 Summary
In summary, there is some evidence to suggest a relationship between neuroticism and chronic pain. Sufferers may display moderately higher levels of neuroticism than pain-free individuals. In addition, neuroticism may affect adjustment to ongoing pain, increasing suffering and disability, and potentially contributing to the development of chronic pain. However, many of the studies do not control for anxiety and depression which may be confounding variables when measuring neuroticism. Moreover, neuroticism represents only one trait while most models of personality functioning such as the MMPI, five-factor model and temperament and character inventory include multiple personality dimensions. Therefore, neuroticism in and of itself cannot represent a pain personality type – either for a sub-group or a greater whole of chronic pain sufferers.
4.3 Studies investigating personality disorders and attachment
While the trait theorists focussed on personality profiles from empirical personality questionnaires, another approach since the 1980s has examined personality disorders in the chronic pain population through structured and semi-structured clinical interviews. Compared to rates in the general and even psychiatric population, the prevalence of personality disorders in chronic pain populations is higher, ranging from 31% to 59% [5]. While some have argued that certain personality disorders may pre-dispose individuals to develop chronic pain [84], others have suggested that a stress-diathesis model may explain the higher incidence of personality disorders in the chronic pain population. While the Diagnostic and Statistical Manual of Mental Disorders-5 [8] suggests that personality disorders represent ‘a longstanding and life-long pattern of internal and external behaviours’, the stress-diathesis model posits that an acute stressor such as ongoing pain may exacerbate underlying personality vulnerabilities, and if not adequately managed, result in a personality disorder. There is growing support for the stress-diathesis model of chronic pain and personality disorders [85,86].
Another approach which has conceptualised chronic pain as a stressor for the onset of personality difficulties is the attachment-diathesis model of chronic pain [87]. This model suggests that insecure attachment is a risk factor for development of chronic pain and a vulnerability factor for poorer outcome and disability. Evidence from several studies suggests that insecure attachment is linked to psychosocial variables such as heightened threat perceptions around pain, less adaptive coping and more negative perceptions of available social support. According to the model, these psychosocial variables may affect onset, maintenance and adjustment to chronic pain.
These stress-diathesis models raise important questions about the causality of personality and pain. Do particular personality characteristics lead to chronic pain or does the onset of chronic pain trigger personality dysfunction? Or perhaps, there is a dynamic interaction between the two. Others have suggested that this question is more complex than just bidirectional causality. For example, Fernandez and Kerns suggest affective disturbance and pain may be framed in terms of predisposing, precipitative, perpetuating and exacerbating factors as well as consequences [88].
This issue of causality has also been raised as an issue of personality measurement given that there is now strong evidence that state factors (such as chronic pain) may influence or distort trait measurement [89]. Therefore, it cannot be assumed that personality measurement after chronic pain onset reflects a stable pre-pain personality. This has implications for many studies (including the ones in this review) which measure personality after onset. However, regardless of causality, the stress-diathesis model of chronic pain and personality may still be compatible with a common personality profile, as perhaps the exacerbation of trait vulnerabilities, including those that maybe more prominent in chronic pain, is due to changes brought on by pain itself. However, further investigation into the nature and direction of causality is needed.
In summary, it appears that personality disorders are more prevalent in the chronic pain population. Insecure attachment may also be a contributing factor to personality and psychosocial difficulties in the pain context. There is much anecdotal evidence from clinicians about personality difficulties amongst chronic pain patients such as heightened dependency, anxiety and aggression. However, because much past evidence has been inconclusive, new frameworks are required to assess this relationship and provide more explanatory power.
5 New evidence for a pain personality
5.1 The Temperament and Character Inventory (TCI-R)
In line with the biopsychosocial approach to chronic pain, Robert Cloninger, a molecular biologist and psychiatrist, published the Temperament and Character inventory in 1994 [90]. Cloninger divides personality into 4 temperament and 3 character dimensions, with temperament reflecting genetically determined personality characteristics and character reflecting traits affected by learning. Temperament traits include: harm avoidance; reward dependence; novelty seeking and persistence. Character traits include: self-directedness; cooperativeness and self-transcendence. The temperament dimensions manifest as automatic emotional responses to experience and reflect neurotransmitter systems in the brain. Harm avoidance is linked to serotonin, reward dependence is linked to noradrenalin, and novelty seeking is linked to dopamine. In contrast, character dimensions reflect cognitive self-concepts and individual differences in goals and values which influence the choices and meanings of life experience. Cloninger suggests that character dimensions are affected by the environment and experience, and that character matures until late adulthood.
The TCI-R differs from other personality inventories such as the MMPI and NEO-PI, because it suggests that genetic and environmental factors influence personality development differently [90]. Changes in personality and manifestations of personality dysfunction are mainly suggested by the character domain because these can be affected by learning, although temperament, which is biologically determined, may influence the type of personality problem. The TCI-R may also be particularly relevant to chronic pain because serotonin, the neurotransmitter related to harm avoidance, is implicated in the inhibition of pain in the central nervous system [91,92].
5.2 A personality profile of higher harm avoidance and lower self-directedness
A new line of evidence suggests that the TCI-R may identify a personality profile common to chronic pain sufferers. A number of studies have found significantly higher harm avoidance (HA) and lower self-directedness (SD) compared to healthy controls and normative samples in chronic pain sufferers. People with high HA are often described as being worrying and fearful, sensitive to criticism and punishment, and pessimistic even in situations that do not worry other people. They are more likely to develop conditioned fear responses and require more reassurance and encouragement. Individuals low in SD are often described as blaming, destructive, fragile and lacking an internal locus of control, which prevents them from setting and meeting meaningful goals. They also tend to have low self-efficacy which further impacts motivational states and self-esteem.
This profile is found in studies reflecting a range of pain types such as fibromyalgia [93,94,95,96], migraine and chronic tension type headache [97,98,99], non-specific musculo-skeletal disorders [100], as well as temporomandibular disorder, trigeminal neuropathy and heterogeneous chronic pain groups [101,102,103,104].
For example, in a controlled study, Conrad et al. [102] administered the TCI-R to 207 heterogeneous chronic pain sufferers and 105 pain-free controls and found that the chronic pain group displayed higher levels of HA and lower SD and Co-operativeness (CO), even after controlling for anxiety and depression. Malmgren-Olsson and Bergdahl [100] also found similar results when they compared 78 sufferers with musculo-skeletal pain and 118 healthy controls. They also found that HA and SD correlated with depression and anxiety symptoms. Given the high comorbidity of mood and anxiety disorders in chronic pain, the authors suggested that the profile of higher HA and lower SD may suggest a ‘mood and pain prone personality type’.
In addition, Mazza et al. [93] administered the TCI-R to 60 fibromyalgia sufferers and 80 healthy controls before and after a 6-month SSRI treatment. They found higher levels of HA and lower levels of SD before treatment in the pain group. After treatment, HA scores were reduced and SD scores were increased, and both remained significantly different from the control group. When depression symptoms were added as a covariate, HA was still significantly higher than controls, and SD no longer achieved significance. This suggests that SD may be more state dependent than HA, in line with Cloninger’s theory.
Gustin et al. [101] further explored a ‘mutual pain personality’ by comparing patients with temporomandibular disorder (nociceptive pain) and trigeminal neuropathy (neuropathic pain). They found that both groups had significantly higher HA and lower SD compared to a healthy control group. The authors suggested that this was significant because previous studies had only compared single chronic pain diagnoses such as headache and migraine, whereas this study compared the two broad categories of chronic pain: neuropathic and nociceptive pain, while also controlling for pain site. Therefore, a similar personality profile of higher HA and lower SD in these two different pain groups may suggest ‘a mutual personality profile’ in chronic pain sufferers in general. Indeed after evaluating the evidence in his review paper, and noting that the majority of studies found this TCI-R personality profile, Conrad et al. [92] suggested that higher HA and lower SD may be the most distinguishing personality feature of chronic pain sufferers thus far in the research.
Furthermore, several studies also suggest that higher HA and lower SD may be associated with Cluster C or ‘fearful’ personality disorders, such as avoidant, obsessive-compulsive and dependent personality disorders [96,102,105,106]. For example, Garcia-Fontanals et al. [96] found alongside a profile of higher HA and lower SD for chronic pain sufferers, that nearly one third met the DSM criteria for a Cluster C personality disorder. Conrad et al. [102] found that 27% of chronic pain patients met criteria for Cluster C personality disorders.
While the results of these studies display promising findings, some limitations of the research should be noted. Firstly, while a majority of studies have found a profile of higher HA and lower SD in chronic pain sufferers, not all have done so [107,108]. Secondly, another interesting observation is that higher HA and lower SD may also be found in depression and anxiety sufferers. Indeed HA is conceptualised as a temperamental vulnerability for developing anxiety and depression [90]. Therefore, when measuring the personality of chronic pain sufferers, mood and anxiety symptoms must be carefully controlled to ensure that higher HA and lower SD independently reflect chronic pain, not only state factors. Many of the studies do control for these variables [94,96,100,102,104] and find this profile to reflect chronic pain independent of state factors, although they are often highly correlated. Given the high comorbidity of depression and anxiety with chronic pain, this seems very reasonable. However, not all studies do control for depression and anxiety. Therefore, more controlled studies with larger, more representative samples are needed before firm conclusions can be drawn.
5.3 Summary
In summary, evidence is arising that chronic pain sufferers may display a common personality profile of higher HA and lower SD as measured by Cloninger’s TCI-R. This contrasts with past research which has investigated such a phenomenon and either failed to find empirical evidence, produced inconsistent findings or lacked the personality framework to provide a broader personality profile. The early psychodynamic theorists suggested a conversion personality, whereby depressed individuals converted their emotions into physical symptoms; however, this theory was rejected due to lack of objective methods. MMPI studies found some evidence for an ‘emotionally overwhelmed’ subtype; however this profile was not common to all chronic pain sufferers. Investigations into neuroticism, as measured by the NEO-PI and EPI, have provided more promising results and suggest a modest relationship between neuroticism and chronic pain, particularly in terms of adjustment to pain. This is unsurprising, however, because neuroticism and harm avoidance are overlapping constructs with an estimated correlation of .71 [105]. However, measures such as the NEO and EPI provide perhaps a limited personality profile, as the models include only five traits, of which one is relevant. Therefore, heightened neuroticism may not be broad enough to represent a personality profile. Studies investigating personality with the TCI-R represent a new area of research, as many have replicated a profile of higher HA and lower SD in a broad range of chronic pain types. However, not all have done so, and these personality dimensions are often correlated with state factors, so more controlled studies with larger sample sizes are needed. Nevertheless, the preliminary evidence is promising, and importantly, may be useful for treatment.
Finally, it is also necessary to make a few points about the inherent limitations of personality and chronic pain research as most are cohort studies and thus representative sampling is an issue. In addition, much of the research is cross-sectional and therefore cannot contribute to the question of whether personality traits predispose an individual to chronic pain or whether the personality characteristics emerge after the onset of pain.
Moreover, a profile of higher HA and lower SD, while important to chronic pain may not be exclusive to it, just as elevated neuroticism may be found amongst people with different mental and health disorders [39]. Other conditions known to display this profile include menopause [109], as well as anxiety [110,111], and mood disorders [112,113]. Thus, the trans-diagnostic nature of this personality profile highlights the interconnectedness of physical and mental health problems.
5.4 Clinical implications of higher harm avoidance and lower self-directedness
So, what does a personality profile of higher HA and lower SD mean and how can it help chronic pain treatment? We suggest that assessing for this personality profile may help to conceptualise underlying mechanisms of chronic pain and help treat the complexity of chronic pain presentations.
Firstly, we argue that such a personality profile may be a factor in individuals developing a fear-avoidance response to pain, which contributes to the development and maintenance of chronic pain (Fig. 1). There is growing evidence for the fear avoidance model in the development and maintenance of chronic pain [68,114,115]. This model suggests that certain personality traits may be a vulnerability factor in developing greater fear around pain [9]. We suggest that elevated HA and lower SD may represent such a personality vulnerability which may lower the threshold at which pain is perceived as threatening. As a result, higher HA sufferers may be more likely to anticipate pain with fearful, catastrophic thoughts, which may develop into chronic rumination and worry. In line with the fear avoidance model [9], these negative appraisals may then lead to pain-related fear which results in avoidance of feared movement and activities. Consequently, this avoidance then results in disuse, disability and depression, further exacerbating the pain experience and maintaining a vicious cycle of fear and avoidance, which is often characteristic of chronic pain sufferers.
Vicious cycle of chronic pain, harm avoidance and self-directedness; HA: harm avoidance, SD: self-directedness.
Lower self-directedness, which is closely related to self-efficacy, may make it more difficult for chronic pain sufferers to prevent and overcome this vicious cycle. This is because they lack the skills to set and achieve meaningful goals and cope actively. Therefore, sufferers scoring lower in SD may find it difficult to stop chronic rumination, to take action to overcome avoidance and to engage in more active coping behaviours.
Therefore, assessing and addressing higher HA and lower SD may be useful for treatment. Research suggests that anxiety related personality traits can be improved with cognitive-behavioural therapy (CBT) [116], and CBT anxiety treatment protocols are suggested to be effective for chronic pain management [117,118]. Cognitive restructuring may help to address catastrophic thinking. Graded exposure and behavioural experiments for feared activities may help to address avoidance and fearful beliefs. For example, a sufferer who fears that ‘bending’ or ‘gardening’ will cause re-injury, can be exposed to such activities in order to disconfirm catastrophic beliefs and reduce fear.
Cognitive behavioural treatments may also be useful in addressing lower self-directedness in individuals. Indeed cognitive behavioural treatment has been found to improve SD [102]. Useful components include goal setting, communication and assertiveness skills, active coping skills and problem solving.
Moreover, high HA is suggested to be a vulnerability factor in developing mood and anxiety disorders [90]. Given the high comorbidity of these disorders with chronic pain, it is possible that there may be a shared vulnerability to developing pain, anxiety and depressive symptoms [119]. Therefore, a transdiagnostic approach may be useful in reducing the emotional suffering and disability linked to chronic pain. Trials of cognitive behaviour therapy which include components for chronic pain, anxiety and depression have produced promising results [120,121].
While CBT treatment for chronic pain creates modest improvements for sufferers, outcomes could be greatly improved. Harm avoidance and self-directedness represent broader and deeper constructs than fear-avoidance and self-efficacy, which are common targets of CBT treatment. HA is broader than fear-avoidance as it not only refers to cognitive-behavioural correlates of fear, it also refers to other personality characteristics which may compound adjustment to chronic pain such as pessimistic thinking, chronic tiredness, fatigue-proneness, the need for reassurance, and sensitivity to criticism and punishment. Similarly, SD is a broader dimension than self-efficacy because it encompasses not only the belief that one can achieve personal goals, but also personality features such as blaming, destructiveness, fragility of character, and a tendency to live a life more influenced by environmental factors than internal values and goals. Therefore, assessing for higher HA and lower SD will enhance case formulation and may signal the need for broader and deeper treatment methods. For example, if a patient is sensitive to criticism or has a strong need for re-assurance, therapies such as schema therapy which focus on the quality of the therapist-client relationship and address attachment needs may engender a greater sense of self and security in the client, a reduced need for re-assurance and thus enhanced resilience. Another target for treatment included in SD is a tendency towards self-destructiveness. For example, drug overuse is a problem in chronic pain populations. Dialectical behaviour therapy strategies such as distress tolerance and emotion regulation skills specifically address such destructive behaviours. There is some evidence to support application of these skills in chronic pain treatment [122].
Thus, assessing HA and SD may help clinicians anticipate clients who are less responsive to treatment, and more vulnerable to co-morbidity and the vicious cycle of chronic pain, suffering and disability.
5.5 Recent developments in personality and neuroscience
A final note on recent developments in neuroscience, plasticity, personality and pain: recent evidence from MRI imaging studies suggests that chronic pain may be linked to subtle changes in brain anatomy, which may result in changes in personality [123]. It is generally accepted that gross damage to certain brain areas such as the prefrontal cortex can result in personality changes; the case of Phineus Gage [124] is a well-known example. However, recent advances in brain imaging techniques make it possible to explore more subtle brain changes, which may also result in alterations in personality. In exploratory research, Gustin et al. [123] found that there are differences in neuronal dendritic length and spine densities in the prefrontal cortex in chronic neuropathic pain sufferers compared to healthy controls. This difference was found in brain areas underpinning personality traits and was correlated with reduced novelty seeking scores as measured by the TCI-R. These results indicated that brain differences may reflect reduced functioning in personality. Another recent study [125] found that lower levels of prefrontal N-acetylaspartate (NAA), a biochemical measure of neuronal integrity [126], were significantly correlated with higher harm avoidance in chronic pain sufferers compared to healthy controls. This indicates that perhaps some of the higher incidence of fear and worry in those with chronic pain is linked to subtle changes in neuronal integrity due to chronic pain itself. Interestingly, the animal model of pain has shown that the pre-frontal cortex is altered after nerve injury, and that this only occurs on the contra-lateral brain side to the injury [127]. This provides evidence that the changes in the prefrontal cortex occur after onset of pain and may result in changes in emotion, personality and cognition. While much more human longitudinal research is needed, these findings strongly support the idea that biochemical and structural changes occur in the prefrontal cortex in chronic pain and that they are also correlated with personality.
Highlights
Personality factors are important for understanding chronic pain development and maintenance.
Different chronic pain types share a profile of higher harm avoidance and lower self-directedness.
This profile helps explain complex presentations and may improve treatment.
The past 120 years of research into chronic pain and personality are summarised.
DOI of refers to article: http://dx.doi.org/10.1016/j.sjpain.2017.08.019.
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Funding
This work was supported by the National Health and Medical Research Council of Australia (GNT1084240) and the Rebecca L. Cooper Medical Research Foundation.
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Ethical issues
Ethic Board approval was not required for this critical review.
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Conflicts of interest
The authors have no conflict of interest to report.
References
[1] Turk DC, Okifuji A. Psychological factors in chronic pain: evolution and revolution. J Consult Clin Psychol 2002;70:678–90.Search in Google Scholar
[2] Haythornthwaite JA, Benrud-Larson LM. Psychological aspects ofneuropathic pain. Clin J Pain 2000;16:S101-5.Search in Google Scholar
[3] Daniel HC, Narewska J, Serpell M, Hoggart B, Johnson R, Rice AS. Comparison of psychological and physical function in neuropathic pain and nociceptive pain: implications for cognitive behavioral pain management programs. Eur J Pain 2008;12:731–41.Search in Google Scholar
[4] Gustin SM, Wilcox SL, Peck CC, Murray GM, Henderson LA. Similarity of suffering equivalence of psychological and psychosocial factors in neuropathic and non-neuropathic orofacial pain patients. Pain 2011;152:825–32.Search in Google Scholar
[5] Weisberg JN, Keefe FJ. Personality, individual differences, and psychopathology in chronic pain. In: Psychosocial factors in pain: critical perspectives. New York, NY, USA: Guilford Press; 1999. p. 56-73.Search in Google Scholar
[6] Asghari M, Nicholas M. Personality and adjustment to chronic pain. Pain Rev 1999;6:85–97.Search in Google Scholar
[7] Weisber JN. Personality and personality disorders in chronic pain. Curr Rev Pain 2000;4:60–70.Search in Google Scholar
[8] Association AP. Diagnostic and statistical manual of mental disorders (DSM-5®). American Psychiatric Pub; 2013.Search in Google Scholar
[9] Vlaeyen JW, Linton SJ. Fear-avoidance and its consequences in chronic musculoskeletal pain: a state of the art. Pain 2000;85:317–32.Search in Google Scholar
[10] Turk DC. Biopsychosocial perspective on chronic pain. In: Psychological approaches to pain management: a practitioner’s hand book. New York, NY, USA: Guilford Press; 1996. p. 3-32.Search in Google Scholar
[11] Merskey H. History of psychoanalytic ideas concerning pain; 2000.Search in Google Scholar
[12] Bonica JJ, Fishman S, Ballantyne J, Rathmell JP. Bonica’s management of pain. Lippincott Williams & Wilkins; 2010.Search in Google Scholar
[13] Bonica JJ. The management of pain. Lippincott Williams & Wilkins; 1990.Search in Google Scholar
[14] Gamsa A. The role of psychological factors in chronic pain. I. A half century of study. Pain 1994;57:5–15.Search in Google Scholar
[15] Breuer J, Freud S. 1893-1895 Studies on Hysteria Standard Edition 2. London: Hogarth Press; 1955.Search in Google Scholar
[16] Engel GL. “Psychogenic” pain and the pain-prone patient. Am J Med 1959;26:899–918.Search in Google Scholar
[17] Blumer D, Heilbronn M. The pain-prone disorder: a clinical and psychological profile. Psychosomatics 1981;22:395–402.Search in Google Scholar
[18] Merskey H, Spear FG. Pain: psychological and psychiatric aspects. Bailliere: Tindall & Cassell; 1967.Search in Google Scholar
[19] Roy R. Engel’s pain-prone disorder patient: 25 years after. Psychother Psychosom 1985;43:126–35.Search in Google Scholar
[20] Hanvik LJ. MMPI profiles in patients with low-back pain. J Consult Psychol 1951;15:350.Search in Google Scholar
[21] Naliboff BD, Cohen MJ, Yellen AN. Does the MMPI differentiate chronic illness from chronic pain? Pain 1982;13:333–41.Search in Google Scholar
[22] Gentry WD, Shows WD, Thomas M. Chronic low back pain: a psychological profile. Psychosomatics 1974;15:174–7.Search in Google Scholar
[23] Moore J, Armentrout D, Parker J, Kivlahan D. Empirically-derived pain patient MMPI subgroups: prediction of treatment outcome. Pain 1984;18:S178.Search in Google Scholar
[24] Armentrout DP, Moore JE, Parker JC, Hewett JE, Feltz C. Pain-patient MMPI subgroups: the psychological dimensions of pain. J Behav Med 1982;5:201–11.Search in Google Scholar
[25] Bradley LA, Van der Heide LH. Pain-related correlates of MMPI profile subgroups among back pain patients. Health Psychol 1984;3:157–74.Search in Google Scholar
[26] Prokop CK, Bradley LA, Margolis R, Gentry WD. Multivariate analysis of the MMPI profiles of patients with multiple pain complaints. J Pers Assess 1980;44:246–52.Search in Google Scholar
[27] Deardorff WW, Chino AF, Scott DW. Characteristics of chronic pain patients: factor analysis of the MMPI-2. Pain 1993;54:153–8.Search in Google Scholar
[28] Sternbach RA, Wolf SR, Murphy RW, Akeson WH. Aspects of chronic low back pain. Psychosomatics 1973;14:52–6.Search in Google Scholar
[29] Sternbach RA. Pain patients: traits and treatment. Academic Press; 1974.Search in Google Scholar
[30] Sternbach RA, Wolf SR, Murphy RW, Akeson WH. Traits of pain patients: the low-back “loser”. Psychosomatics 1973;14:226–9.Search in Google Scholar
[31] Hansen FR, Biering-Sorensen F, Schroll M. Minnesota multiphasic personality inventory profiles in persons with orwithout low back pain: a 20-year follow-up study. Spine 1995;20:2716–20.Search in Google Scholar
[32] Gatchel RJ, Polatin PB, Mayer TG. The dominant role of psychosocial risk factors in the development of chronic low back pain disability. Spine 1995;20:2702–9.Search in Google Scholar
[33] Gatchel RJ, Polatin PB, Kinney RK. Predicting outcome of chronic back pain using clinical predictors of psychopathology: a prospective analysis. Health Psychol 1995;14:415–20.Search in Google Scholar
[34] Bigos SJ, Battie MC, Spengler DM, Fisher LD, Fordyce WE, Hansson TH, Nachemson AL, Wortley MD. A prospective study of work perceptions and psychosocial factors affectingthe report ofback injury. Spine 1991;16:1–6.Search in Google Scholar
[35] Love AW, Peck CL. The MMPI and psychological factors in chronic low back pain: a review. Pain 1987;28:1–12.Search in Google Scholar
[36] Tarescavage AM, Scheman J, Ben-Porath YS. Reliability and validity of the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) in evaluations of chroni low back pain patients. Psychol Assess 2015;27:433–46.Search in Google Scholar
[37] Costa PT, McCrae RR. Normal personality assessment in clinical practice: the NEO Personality Inventory. Psychol Assess 1992;4:5.Search in Google Scholar
[38] Eysenck HJ, Eysenck S. The Eysenck personality inventory; 1965.Search in Google Scholar
[39] Lahey BB. Public health significance of neuroticism. Am Psychol 2009;64:241–56.Search in Google Scholar
[40] Mendelson G. Compensation, pain complaints, and psychological disturbance. Pain 1984;20:169–77.Search in Google Scholar
[41] Bucourt E, Martaille V, Mulleman D, Goupille P, Joncker-Vannier I, Huttenberger B, Reveillere C, Courtois R. Comparison of the Big Five personalitytraits in fibromyalgia and other rheumatic diseases. Joint Bone Spine 2016.Search in Google Scholar
[42] Martinez MP, Sanchez AI, Miro E, Medina A, Lami MJ. The relationship between the fear-avoidance model of pain and personality traits in fibromyalgia patients. JClin Psychol Med Settings 2011;18:380–91.Search in Google Scholar
[43] Shivarathre DG, Howard N, Krishna S, Cowan C, Platt SR. Psychological factors and personalitytraits associatedwith patients inchronic foot and ankle pain. Foot Ankle Int 2014;35:1103–7.Search in Google Scholar
[44] Callahan CD. Stress, coping, and personality hardiness in patients with temporomandibular disorders. Rehabil Psychol 2000;45:38–48.Search in Google Scholar
[45] Aaseth K, Grande R, Leiknes K, Benth J, Lundqvist C, Russell M. Personality traits and psychological distress in persons with chronic tension-type headache. The Akershus study of chronic headache.Acta Neurol Scand 2011;124:375–82.Search in Google Scholar
[46] Tanum L, Malt UF. Personality and physical symptoms in nonpsychiatric patients with functional gastrointestinal disorder. J Psychosom Res 2001;50:139–46.Search in Google Scholar
[47] Bond M. The relation of pain to the Eysenck personality inventory, Cornell medical index and Whiteley index of hypochondriasis. Br J Psychiatry 1971;119:671–8.Search in Google Scholar
[48] Merskey H, Boyd D. Emotional adjustment and chronic pain. Pain 1978;5:173–8.Search in Google Scholar
[49] Valdes M, Treserra J, Garcia L, de Pablo J, De Flores T. Psychogenic pain and psychological variables: a psychometric study. Psychother Psychosom 1988;50:15–21.Search in Google Scholar
[50] Wade JB, Dougherty LM, Hart RP, Cook DB. Patterns of normal personality structure among chronic pain patients. Pain 1992;48:37–43.Search in Google Scholar
[51] Nitch SR, Boone KB. Normal personality correlates of chronic pain subgroups. J Clin Psychol Med Settings 2004;11:203–9.Search in Google Scholar
[52] Soriano J, Monsalve V, Gomez-Carretero P, Ibanez E. Vulnerable personality profile in patients with chronic pain: relationship with coping, quality oflife and adaptationto disease. Int J Psychol Res 2012;5:42–51.Search in Google Scholar
[53] Torres X, Bailles E, Valdes M, Gutierrez F, Peri J-M, Arias A, Gomez E, Collado A. Personality does not distinguish people with fibromyalgia but identifies subgroups of patients. Gen Hosp Psychiatry 2013;35:640–8.Search in Google Scholar
[54] Henryk-Gutt R, Rees WL. Psychological aspects of migraine. J Psychosom Res 1973;17:141–53.Search in Google Scholar
[55] Merlijn VP, Hunfeld JA, van der Wouden JC, Hazebroek-Kampschreur AA, Koes BW, Passchier J. Psychosocial factors associated with chronic pain in adolescents. Pain 2003;101:33–43.Search in Google Scholar
[56] Breslau N, Chilcoat HD, Andreski P. Further evidence on the link between migraine and neuroticism. Neurology 1996;47:663–7.Search in Google Scholar
[57] Wade JB, Price DD. Nonpathological factors in chronic pain: Implications for assessment and treatment. In: Personality characteristics of patients with pain. Washington, DC, USA: American Psychological Association; 2000. p. 89-107.Search in Google Scholar
[58] Philips HC, Jahanshahi M. Theeffects ofpersistent pain: the chronic headache sufferer. Pain 1985;21:163–76.Search in Google Scholar
[59] Contrada RJ, Cather C, O’Leary A. Personality and health: dispositions and processes in disease susceptibility and adaptation to illness; 1999.Search in Google Scholar
[60] Smith TW, MacKenzie J. Personalityand riskofphysical illness. Annu RevClin Psychol 2006;2:435–67.Search in Google Scholar
[61] Pietri-Taleb F, Riihimaki H, Viikari-Juntura E, Lindstrom K. Longitudinal study on the role of personality characteristics and psychological distress in neck trouble among working men. Pain 1994;58:261–7.Search in Google Scholar
[62] Wilner JG, Vranceanu AM, Blashill AJ. Neuroticism prospectively predicts pain among adolescents: results from a nationally representative sample. J Psychosom Res 2014;77:474–6.Search in Google Scholar
[63] Lynn R, Eysenck H. Tolerance forpain, extraversion, and neuroticism. Percept MotorSkills 1961.Search in Google Scholar
[64] Ramirez-Maestre C, Esteve R. Disposition and adjustment to chronic pain. Curr Pain Headache Rep 2013;17:312.Search in Google Scholar
[65] Evers AW, Kraaimaat FW, van Riel PL, Bijlsma JW. Cognitive, behavioral and physiological reactivityto pain as a predictoroflong-term pain in rheumatoid arthritis patients. Pain 2001;93:139–46.Search in Google Scholar
[66] Rudy TE, Turk DC, Kubinski JA, Zaki HS. Differential treatment responses of TMD patients as a function of psychological characteristics. Pain 1995;61:103–12.Search in Google Scholar
[67] Paine P, Worthen SF, Gregory LJ, Thompson DG, Aziz Q. Personality differences affect brainstem autonomic responses to visceral pain. Neurogastroenterol Motil 2009;21:1155–98.Search in Google Scholar
[68] Leeuw M, Goossens ME, Linton SJ, Crombez G, Boersma K, Vlaeyen JW. The fear-avoidance model of musculoskeletal pain: current state of scientific evidence. J Behav Med 2007;30:77–94.Search in Google Scholar
[69] Asghari A, Nicholas MK. Personality and pain-related beliefs/coping strategies: a prospective study. Clin J Pain 2006;22:10–8.Search in Google Scholar
[70] Wade JB, Dougherty LM, Hart RP, Rafii A, Price DD. A canonical correlation analysis of the influence of neuroticism and extraversion on chronic pain, suffering, and painbehavior. Pain 1992;51:67–73.Search in Google Scholar
[71] Harkins SW, Price DD, Braith J. Effects of extraversion and neuroticism on experimental pain, clinical pain, and illness behavior. Pain 1989;36:209–18.Search in Google Scholar
[72] Williams DA, Robinson ME, Geisser ME. Pain beliefs: assessment and utility. Pain 1994;59:71–8.Search in Google Scholar
[73] Affleck G, Tennen H, Urrows S, Higgins P. Neuroticism and the pain-mood relation in rheumatoid arthritis: insights from a prospective daily study. J Consult Clin Psychol 1992;60:119–26.Search in Google Scholar
[74] Ramirez-Maestre C, Martinez AEL, Zarazaga RE. Personality characteristics as differential variables of the painexperience. J Behav Med 2004;27:147–65.Search in Google Scholar
[75] Conner TS, Tennen H, Zautra AJ, Affleck G, Armeli S, Fifield J. Coping with rheumatoid arthritis pain in daily life: within-person analyses reveal hidden vulnerability forthe formerlydepressed. Pain 2006;126:198–209.Search in Google Scholar
[76] Miro J, Raich RM. Personalitytraits and pain experience. Pers Individual Differ 1992;13:309–13.Search in Google Scholar
[77] Kadimpati S, Zale EL, Hooten MW, Ditre JW, Warner DO. Associationsbetween neuroticism and depression in relation to catastrophizing and pain-related anxiety in chronic pain patients. PLOS ONE 2015;10.Search in Google Scholar
[78] Wong W, Lam H, Chen P, Chow Y, Wong S, Lim H, Jensen M, Fielding R. The fear-avoidance model of chronic pain: assessing the role of neuroticism and negative affect in pain catastrophizin using structural equation modeling. Int J BehavMed 2015;22:118–31.Search in Google Scholar
[79] Goubert L, Crombez G, Van Damme S. The role of neuroticism, pain catas-trophizing and pain-related fear in vigilance to pain: a structural equations approach. Pain 2004;107:234–41.Search in Google Scholar
[80] Vancleef LMG, Peters ML, Roelofs J, Asmundson GJG. Do fundamental fears differentially contribute to pain-related fear and pain catastrophizing? An evaluation of the sensitivity index. EurJ Pain 2006;10:527.Search in Google Scholar
[81] Carleton RN, Asmundson GJ. The multidimensionality of fear of pain: construct independence for the Fear of Pain Questionnaire-Short Form and the PainAnxiety Symptoms Scale-20. J Pain 2009;10:29–37.Search in Google Scholar
[82] Asmundson GJ, Norton GR. Anxiety sensitivity in patients with physically unexplained chronic back pain: a preliminary report. Behav Res Ther 1995;33:771–7.Search in Google Scholar
[83] Norton PJ, Asmundson GJG. Anxiety sensitivity, fear, and avoidance behavior in headache pain. Pain 2004;111:218–23.Search in Google Scholar
[84] Weisberg JN, Keefe FJ. Personality disorders in the chronic pain population: basic concepts, empirical findings, and clinical implications. Pain Forum 1997:1-9.Search in Google Scholar
[85] Weisberg JN. Studies investigatingthe prevalence of personality disorders in patients with chronic pain. In: Personality characteristics of patients with pain. Washington, DC, USA: American Psychological Association; 2000. p. 221-39.Search in Google Scholar
[86] Weisberg JN, Boatwright BA. Mood, anxiety and personality traits and states in chronic pain. Pain 2007;133:1–2.Search in Google Scholar
[87] Meredith P, Ownsworth T, Strong J. A review of the evidence linking adult attachment theory and chronic pain: presenting a conceptual model. Clin Psychol Rev 2008;28:407–29.Search in Google Scholar
[88] Fernandez E, Kerns R. Pain and affective disorders: looking beyond the “chicken and egg” conundrum. In: Pain comorbidities. Seattle: IASP Press; 2012. p. 279-96.Search in Google Scholar
[89] Fishbain DA, Cole B, Cutler R, Lewis J, Rosomoff HL, Rosomoff R. Chronic pain and the measurement of personality: do states influence traits? Pain Med 2006;7:509–29.Search in Google Scholar
[90] Cloninger CR, Przybeck TR, Svrakic DM. The Temperament and Character Inventory (TCI): a guide to its development and use. St.Louis, MO: Center for Psychobiology of Personality, Washington University; 1994.Search in Google Scholar
[91] Ziv M, Tomer R, Defrin R, Hendler T. Individual sensitivityto pain expectancy is related to differential activation of the hippocampus and amygdala. Hum Brain Mapp 2010;31:326–38.Search in Google Scholar
[92] Conrad R, Wegener I, Geiser F, Kleiman A. Temperament, character, and personality disorders in chronic pain. Curr Pain Headache Rep 2013;17:318.Search in Google Scholar
[93] Mazza M, Mazza O, Pomponi M, Di Nicola M, Padua L, Vicini M, Bria P, Mazza S. What is the effect of selective serotonin reuptake inhibitors on temperament and character in patients with fibromyalgia? Compr Psychiatry 2009;50:240–4.Search in Google Scholar
[94] Gencay-Can A, Can SS. Temperament and character profile of patients with fibromyalgia. Rheumatol Int 2012;32:3957–61.Search in Google Scholar
[95] Lundberg G, Anderberg UM, Gerdle B. Personality features in female fibromyalgia syndrome. J Musculoskelet Pain 2009;17:117–30.Search in Google Scholar
[96] Garcia-Fontanals A, Garcia-Blanco S, Portell M, Pujol J, Poca-Dias V, Garcia-Fructuoso F, Lopez-Ruiz M, Gutierrez-Rosado T, Goma-i-Freixanet M, Deus J. Cloninger’s psychobiological model ofpersonality and psychological distress in fibromyalgia. Int J Rheum Dis 2014.Search in Google Scholar
[97] Boz C, Gazioglu S, Altunayoglu V, Hocaoglu C. Effect of serotonergic antidepressant therapy on temperament and character scales in patients with chronic tension-type headache. Psychiatry Clin Neurosci 2007;61: 534-42.Search in Google Scholar
[98] Mongini F, Rota E, Evangelista A, Ciccone G, Milani C, Ugolini A, Ferrero L, Mongini T, Rosato R. Personality profiles and subjective perception of pain in head pain patients. Pain 2009;144:125–9.Search in Google Scholar
[99] Abbate-Daga G, Fassino S, Giudice RL, Rainero I, Gramaglia C, Marech L, Amianto F, Gentil S, Pinessi L. Anger, depression and personality dimensions in patients with migraine without aura. Psychother Psychosom 2007;76:122–8.Search in Google Scholar
[100] Malmgren-Olsson E-B, Bergdahl J, Temperament. Character personality dimensions in patients with nonspecific musculoskeletal disorders. Clin J Pain 2006;22:625–31.Search in Google Scholar
[101] Gustin SM, Burke LA, Peck CC, Murray GM, Henderson LA. Pain and personality: do individuals with different forms of chronic pain exhibit a mutual personality? Pain Pract 2015.Search in Google Scholar
[102] Conrad R, Schilling G, Bausch C, Nadstawek J, Wartenberg HC, Wegener I, Geiser F, Imbierowicz K, Liedtke R. Temperament and character personality profiles and personality disorders in chronic pain patients. Pain 2007;133:197–209.Search in Google Scholar
[103] Sanchez-Roman S, Tellez-Zenteno JF, Zermeno-Phols F, Garcia-Ramos G, Velazquez A, Derry P, Hernandez M, Resendiz A, Guevara-Lopez UM. Personality in patients with migraine evaluated with the “Temperament and Character Inventory”. J Headache Pain 2007;8:94–104.Search in Google Scholar
[104] Vargas P, Pares G, Queralto J, Arsegol M, Alvarez S. Personality and chronic pain. Psiquis 2005;26:17–24.Search in Google Scholar
[105] Svrakic DM, Whitehead C, Przybeck TR, Cloninger CR. Differential diagnosis of personality disorders by the seven-factor model of temperament and character. Arch Gen Psychiatry 1993;50:991–9.Search in Google Scholar
[106] Svrakic DM, Draganic S, Hill K, Bayon C, Przybeck T, Cloninger C. Temperament, character, and personality disorders: etiologic, diagnostic, treatment issues. Acta Psychiatr Scand 2002;106:189–95.Search in Google Scholar
[107] Tokura T, Kimura H, Ito M, Nagashima W, Sato N, Kimura Y, Arao M, Aleksic B, Yoshida K, Kurita K. Temperament and character profiles of patients with burning mouth syndrome. J Psychosom Res 2015;78:495–8.Search in Google Scholar
[108] Facchin F, Barbara G, Saita E, Erzegovesi S, Martoni RM, Vercellini P. Personality in women with endometriosis: temperament and character dimensions and pelvic pain. Hum Reprod 2016;31:1515–21.Search in Google Scholar
[109] Kokras N, Stamatelopoulos K, Zervas I, Papadimitriou G, Lambrinoudaki I. EPA-1788 - psychological symptoms in menopause associate with higher harm avoidance and lower self-directedness. Eur Psychiatry 2014;29:1.Search in Google Scholar
[110] Cruz-Fuentes C, Blas C, Gonzalez L, Camarena B, Nicolini H. Severity of obsessive-compulsive symptoms is related to self-directedness character trait in obsessive-compulsive disorder. CNS Spectr 2004;9:607–12.Search in Google Scholar
[111] Wachleski C, Salum GA, Blaya C, Kipper L, Paludo A, Salgado AP, Manfro GG. Harm avoidance and self-directedness as essential features of panic disorder patients. Compr Psychiatry 2008;49:476–81.Search in Google Scholar
[112] Smith DJ, Duffy L, Stewart ME, Muir WJ, Blackwood DH. High harm avoidance and low self-directedness in euthymic young adults with recurrent, early-onset depression. J Affect Disord 2005;87:83–9.Search in Google Scholar
[113] Zaninotto L, Solmi M, Toffanin T, Veronese N, Cloninger CR, Correll CU. A metaanalysis of temperament and character dimensions in patients with mood disorders: comparison to healthy controls and unaffected siblings. J Affect Disord 2016;194:84–97.Search in Google Scholar
[114] Jensen JN, Karpatschof B, Labriola M, Albertsen K. Do fear-avoidance beliefs play a role on the association between low back pain and sickness absence? A prospective cohort study among female health care workers. J Occup Environ Med 2010;52:85–90.Search in Google Scholar
[115] Nieto R, Miro J, Huguet A. The fear-avoidance model in whiplash injuries. Eur J Pain 2009;13:518–23.Search in Google Scholar
[116] Olthuis JV, Watt MC, Mackinnon SP, Potter SM, Stewart SH. The nature of the association between anxiety sensitivity and pain-related anxiety: evidence from correlational and intervention studies. Cogn Behav Ther 2015;44:423–40.Search in Google Scholar
[117] Vlaeyen J, Morley S, Linton SJ, Boersma K, deJong J. Pain-related fear: exposure based treatment for chronic pain; 2012.Search in Google Scholar
[118] Bailey KM, Carleton RN, Vlaeyen JW, Asmundson GJ. Treatments addressing pain-related fear and anxiety in patients with chronic musculoskeleta pain: a preliminary review. Cogn BehavTher 2010;39:46–63.Search in Google Scholar
[119] Asmundson GJ, Katz J. Understanding the co-occurrence of anxiety disorders and chronic pain: state-of-the-art. Depress Anxiety 2009;26:888–901.Search in Google Scholar
[120] Dear BF, Titov N, Perry KN, Johnston L, Wootton BM, Terides MD, Rapee RM, Hudson JL. The Pain Course: a randomised controlled trial of a clinician-guided Internet-delivered cognitive behaviourtherapy program for managing chronic pain and emotional well-being. Pain 2013;154:942–50.Search in Google Scholar
[121] Eccleston C, Williams ACd C, Morley S. Psychological therapies for the management of chronic pain (excludin headache) in adults. In: The cochrane library; 2009.Search in Google Scholar
[122] Allen LB, Tsao JC, Seidman LC, Ehrenreich-May J, Zeltzer LK. A unified, transdiagnostic treatment for adolescents with chronic pain and comorbid anxiety and depression. Cogn Behav Pract 2012;19:56–67.Search in Google Scholar
[123] Gustin SM, McKay JG, Petersen ET, Peck CC, Murray GM, Henderson LA. Subtle alterations in brain anatomy may change an individual’s personality in chronic pain. PLOS ONE 2014;9.Search in Google Scholar
[124] Code C. Classic cases in neuropsychology. Psychology Press; 1996.Search in Google Scholar
[125] Naylor B, Wrigley PJ, Boag S, McAuley JH, Siddall PJ, Rae CD, Gustin SM. More worry, less metabolic activity in the medial prefrontal cortex in people with chronic pain: a spectroscopy study linking harm avoidance with N-acetyl-aspartate and Glutamate. Unpublished data.Search in Google Scholar
[126] Rae CD. A guide to the metabolic pathways and function of metabolites observed in human brain 1H magnetic resonance spectra. Neurochem Res 2014;39:1–36.Search in Google Scholar
[127] Metz AE, Yau H-J, Centeno MV, Apkarian AV, Martina M. Morphological and functional reorganization of rat medial prefrontal cortex in neuropathic pain. Proc Natl Acad Sci 2009;106:2423–8.file-48Search in Google Scholar
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