Neuroticism and common mental disorders: Meaning and utility of a complex relationship
Introduction
The broad personality trait of neuroticism is strongly associated with Axis I psychopathology, in particular the common mental disorders (CMDs), including anxiety, mood, and substance use disorders (e.g. Clark et al., 1994, Kotov et al., 2010, Lahey, 2009, Malouff et al., 2005, Ormel et al., 2001, Ormel and Wohlfarth, 1991, Ruiz et al., 2008). Very recently an important meta-analysis quantified neuroticism's cross-sectional association with CMDs, ranging in magnitude from Cohen's d of 0.5 for substance disorders, to 2.0 for some anxiety and mood disorders (Kotov et al., 2010). Neuroticism is also the single strongest predictor of CMDs although the prospective association is typically weaker compared to the cross-sectional association (de Graaf et al., 2002, Lahey, 2009, Ormel et al., 2004c). Neuroticism also plays an important role in other phenomena that correlate strongly with psychological distress, e.g. persistent low subjective well-being, and physical health problems (Costa and McCrae, 1980, Duncan-Jones et al., 1990, Heller et al., 2004, Watson, 2000). Neuroticism is also associated with important outcomes like occupational attainment, divorce, and mortality (Lahey, 2009, Roberts et al., 2007). Furthermore, neuroticism accounts for a substantial proportion of current and lifetime comorbidity, most strongly within the domain of internalizing disorders, but also between internalizing and externalizing problems (Clark, 2005, Khan et al., 2005, Watson et al., 2006), and between mental and physical illness (Neeleman et al., 2004, Neeleman et al., 2001).
Five fundamental theories have been proposed to explain the neuroticism–CMDs link (Caspi et al., 2005, Clark, 2005, Klein et al., 2011, Krueger and Tackett, 2003, Ormel et al., 2004b, Widiger et al., 1999). (1) The vulnerability model postulates that neuroticism sets in motion processes that lead to CMDs, i.e. high neuroticism either causes the development of CMDs directly or enhances the impact of causal risk factors such as stressful life events (e.g., diathesis-stress scenario). Examples of such processes are a negative bias in attention, interpretation and recall of information, increased reactivity, and ineffective coping. (2) The spectrum model is based on the assumption that neuroticism and CMDs are different manifestations of the same processes, with CMDs representing the high ends of continuously distributed neuroticism. The spectrum model considers high neuroticism scores as equivalent to symptoms of CMD. (3) According to the common cause model is neuroticism predictive for CMDs because the two constructs share genetic and environmental determinants. Shared roots produce non-causal statistical associations between the two. (4) The scar model proposes that neuroticism is shaped by CMDs, in that the experience of a major CMD episode has permanent effects on neuroticism, thus persisting after the episode has remitted. Finally, (5) the state model also asserts that neuroticism is shaped by CMDs but, in contrast with the scar model, argues that the effects of CMDs are temporary and disappear after the episode has remitted. It is important to note that the models are not mutually exclusive and that the borders between them are blurry. Table 1 describes specific predictions of each model, divided into necessary conditions (model is incorrect if condition is not met) and supportive evidence (consistent with the model but absence does not invalidate the model).
The objective of the current paper is to evaluate available evidence bearing on the validity of these models. It is in particular the prospective association linking baseline neuroticism to later CMDs that has encouraged many to consider neuroticism a robust independent and etiologically informative risk factor of CMDs, e.g. (Fanous et al., 2007, Kendler and Prescott, 2006, Khan et al., 2005, Krueger et al., 1996, Lahey, 2009, Ormel and Wohlfarth, 1991, Ormel et al., 2001, van Os et al., 2001, Vink et al., 2009). However, this preference for the vulnerability model may be premature given that research to date has neither critically examined the vulnerability model nor sufficiently evaluated the validity of competing models.
To examine the validity of the models we examined the evidence on the following topics: the prospective association between neuroticism and CMDs; item overlap between measures of neuroticism and CMDs; the extent to which neuroticism and CMDs share determinants; differential change and stability of neuroticism and psychiatric symptoms and disorders, and treatment effects on neuroticism and CMDs. To identify studies examining the prospective association between neuroticism and later axis-1 psychopathology, we searched the Web of Knowledge. This yielded 418 studies, of which 46 met our inclusion criteria.
The present work extends earlier work on cross-sectional associations to a critical evaluation of explanatory models of the prospective association. Three other broad personality traits, low Conscientiousness, Disinhibition, and Extraversion, have often been linked to CMDs as well, but their association with CMDs is not as strong and pervasive as that of neuroticism (Clark, 2005, Fanous et al., 2007, Khan et al., 2005, Klein et al., 2011, Kotov et al., 2010, Malouff et al., 2005). Analyses of these traits are outside the scope of this review, but we believe that the implications of our findings on neuroticism are relevant for understanding the relationship between other personality traits and CMDs as well. First we address briefly the definition and measurement of both neuroticism and CMDs.
Section snippets
Definition and measurement of neuroticism
Neuroticism is one of the broad traits at the apex of personality taxonomy. The term neuroticism has its roots in Freudian theory. The modern concept of neuroticism was introduced by Hans Eysenck and others using a range of methods from personality psychology, including psychophysiological and lexical studies (Eysenck, 1967, Eysenck and Eysenck, 1985, John et al., 2008, Mathews et al., 2003, Pervin and John, 1999, Widiger et al., 1984). The lexical model assumes that language represents what is
Definition and measurement of common mental disorders (CMDs)
Two widely used modern classifications of mental disorders are the Diagnostic Statistical Manual 4th edition (DSM-IV) and the International Classification of Diseases (ICD-10) (Kaplan & Sadock, 1995). Therein mental disorders are defined as a clinically significant behavioral or psychological syndrome or pattern that occurs in a person and associates with present distress (a painful symptom) or disability (impairment in one or more important areas of functioning) or with a significantly
Cross-sectional studies
Recently, Kotov et al. (2010) performed a quantitative review of cross-sectional associations between six higher order personality traits, including neuroticism, and 11 mental disorders, including the CMDs disorders. All diagnostic groups were high on neuroticism (mean Cohen's d = 1.65). As a heuristic to guide interpretation of findings, d's from 0.20 to 0.40 conventionally indicate a small effect, 0.41–0.79 a medium effect, and 0.80 + a large effect. Anxiety disorders showed the strongest link
Operational confounding and the trait-state distinction
In addition to the issues related to adequate control for confounders, the interpretation of associations between neuroticism and CMD is also difficult because of the overlap between item content of neuroticism inventories and measures of CMDs (Duncan-Jones et al., 1990, Ormel et al., 2004c). Many neuroticism items are similar to items of popular symptom measures in that they refer to the same affects, cognitions and behaviors (see for examples: Ormel, Riese, & Rosmalen, 2012).
However, there
Stability and change of neuroticism — different from psychopathology?
Rank-order stability data can shed light on the validity of the models. Rank-order stability reflects the stability of individuals' relative position within the group, also known as differential stability, and is typically established with test–retest correlations. Meta-analytic evidence shows increasing differential stability of personality with age until a peak in late adulthood, as well as decreasing stability with increasing time intervals between measurement occasions (Fraley and Roberts,
Twin studies
Neuroticism is the product of the interplay between genetic and environmental influences. Heritability estimates typically range from 40% to 60% (Eaves et al., 1999, Flint, 2004, Fullerton, 2006, Viken et al., 1994). Similar or slightly lower heritability has been reported for CMDs (Boomsma et al., 2005, Jardine et al., 1984, Kendler et al., 2008, McGuffin et al., 2002, Shih et al., 2004). The genetic influences on neuroticism remain largely the same across adult life, whereas the environmental
Treatment response
There is some evidence that the treatment of depression also reduces neuroticism (Zinbarg, Uliaszek, & Adler, 2008) and that this effect is not entirely due to confounding by the change in depressive state (Tang et al., 2009). Indeed, Quilty and colleagues found that decrease in neuroticism mediates treatment effect on depression (Quilty, Meusel, & Bagby, 2008). More evidence has accumulated that psychiatric treatment has better outcomes in individuals with relatively low neuroticism but the
Implications of evidence for validity of neuroticism–CMD models
Summary of evidence for and against the models is given in Table 5. Much evidence lacks decisive implications for a particular model, presented as +/− in Table 5. At first none of the models seem a clear winner, in that it is capable to account for (virtually) all evidence. Neither does the evidence completely rule out the common cause, spectrum or scar model, although the latter is not very likely because the few studies who found scar effects on neuroticism may have been dealing with decaying
Next steps
These conclusions are necessarily tentative because the existing literature has several limitations. First, few prospective studies controlled for all relevant baseline symptoms and psychiatric history, thus, unique predictive power of neuroticism has not yet been established. Second, while we found substantial evidence directly supporting the common cause and the spectrum models, there are still relatively few data on mechanisms that may convey risk from neuroticism to CMDs, and the pathways
Declaration of interest
Authors report no conflict of interest.
Acknowledgment
Dr. Ormel's research is financially supported by the Netherlands Organization for Scientific Research NWO (Medical Research Council program grant GB-MW 940-38-011; ZonMW Brainpower (Geestkracht) grant 100-001-004; NWO investment grant 175.010.2003.005); NWO Gravitation (Zwaartekracht) grant and by the European Science Foundation (EuroSTRESS project FP-006). Dr. Oldehinkel's research is supported by the NWO Social Sciences Council investment grant GB-MaGW 480-07-001 and project grant 452-04-314.
References (152)
- et al.
Personality traits and the development of depression, hopelessness, and suicide ideation
Personality and Individual Differences
(2005) - et al.
Prediction of the three-year course of recurrent depression in primary care patients: Different risk factors for different outcomes
Journal of Affective Disorders
(2008) - et al.
Personality self-reports are concurrently reliable and valid during acute depressive episodes
Journal of Affective Disorders
(2005) - et al.
The relationship between neuroticism, pre-traumatic stress, and post-traumatic stress: A prospective study
Personality and Individual Differences
(2003) - et al.
Individuals high in neuroticism are not more reactive to adverse events
Personality and Individual Differences
(2009) The genetic basis of neuroticism
Neuroscience and Biobehavioral Reviews
(2004)- et al.
Burden and consequences of child maltreatment in high-income countries
Lancet
(2009) - et al.
The long-term impact of the physical, emotional, and sexual abuse of children: A community study
Child Abuse & Neglect
(1996) - et al.
Personality characteristics of adult survivors of childhood trauma
Journal of Traumatic Stress
(2007) Diagnostic and statistical manual of mental disorders, fourth edition (DSM-IV)
(1994)
Personality and the problems of everyday life: The role of neuroticism in exposure and reactivity to daily stressors
Journal of Personality
Genetic and environmental influences on Anxious/Depression during childhood: A study from the Netherlands twin register
Genes, Brain, and Behavior
Personality and psychopathology: Genetic perspectives
Journal of Abnormal Psychology
Personality development: Stability and change
Annual Review of Psychology
What is being assessed and why it matters: The impact of transient error on trait research
Journal of Personality and Social Psychology
Temperament as a unifying basis for personality and psychopathology
Journal of Abnormal Psychology
Temperament: A new paradigm for trait psychology
Temperament, personality, and the mood and anxiety disorders
Journal of Abnormal Psychology
Childhood and adolescent psychiatric disorders as predictors of young adult disorders
Archives of General Psychiatry
Personality at midlife: Stability, intrinsic maturation, and response to life events
Assessment
Influence of extraversion and neuroticism on subjective well-being: Happy and unhappy people
Journal of Personality and Social Psychology
Revised NEO personality inventory (NEO-PI-R) and the five factor inventory (NEO-FFI): Professional manual
Dimensions of normal personality as networks in search of equilibrium: You can't like parties if you don't like people
European Journal of Personality
Economic costs of neuroticism: A population-based study
Archives of General Psychiatry
Predictors of first incidence of DSM-III-R psychiatric disorders in the general population: Findings from the Netherlands mental health survey and incidence study
Acta Psychiatrica Scandinavica
Genetic, environmental, and epigenetic factors in the development of personality disturbance
Development and Psychopathology
A neurobehavioral dimensional model
Higher-order factors of the big five
Journal of Personality and Social Psychology
A model of stability and change in minor psychiatric symptoms: Results from three longitudinal studies
Psychological Medicine
Comparing the biological and cultural inheritance of personality and social attitudes in the Virginia 30,000 study of twins and their relatives
Twin Research
The molecular genetic architecture of human personality: Beyond self-report questionnaires
Molecular Psychiatry
Relationship between multiple forms of childhood maltreatment and adult mental health in community respondents: Results from the adverse childhood experiences study
The American Journal of Psychiatry
The biological basis of personality
Personality and individual differences. A natural science approach
A longitudinal study of personality and major depression in a population-based sample of male twins
Psychological Medicine
The christchurch health and development study: Review of findings on child and adolescent mental health
The Australian and New Zealand Journal of Psychiatry
Patterns of continuity: A dynamic model for conceptualizing the stability of individual differences in psychological constructs across the life course
Psychological Review
New approaches to the genetic analysis of neuroticism and anxiety
Behavior Genetics
The influence of social factors on common mental disorders destabilisation and restitution
The British Journal of Psychiatry
Childhood adversities and adult psychiatric disorders in the national comorbidity survey replication I associations with first onset of DSM-IV disorders
Archives of General Psychiatry
Corumination, interpersonal stress generation, and internalizing symptoms: Accumulating effects and transactional influences in a multiwave study of adolescents
Development and Psychopathology
Validity of adult retrospective reports of adverse childhood experiences: Review of the evidence
Journal of Child Psychology and Psychiatry
The role of person versus situation in life satisfaction: A critical examination
Psychological Bulletin
A population-based twin study of the relationship between neuroticism and internalizing disorders
The American Journal of Psychiatry
Genetic covariation between neuroticism and the symptoms of anxiety and depression
Genetic Epidemiology
The prospective relationship between neuroticism and psychopathology: a meta-analysis
Sources of cumulative continuity in personality: A longitudinal multiple-rater twin study
Journal of Personality and Social Psychology
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Jeronimus and Kotov contributed equally to this paper.