Fidgeting Behavior During Psychotherapy: Hand Movement Structure Contains Information About Depressive Symptoms

In outpatient psychotherapy, adopting a new perspective and seeing oneself from the observer’s point of view by employing self-observation (Koffert et al. 2019) can be helpful. During a psychotherapy session, therapists take on the observer’s point of view by focusing their attention on their patients. In doing so, therapists focus not only on the verbal content but also on their patients’ nonverbal behavior. Fidgeting is a prominent observable movement behavior in patients with social anxiety disorder (SAD) and persons with subclinical social anxiety and arousal. Fidgeting is associated with SAD, as irregular hand movements, or continuous small-amplitude movements with the hands, were found to decrease over time in ten SAD patients (Kreyenbrink et al. 2017). Fidgeting has also been linked to stress and arousal in healthy persons (Densing et al. 2018). Heerey and Kring (2007) identified a socially anxious group and a non-socially anxious group in a student sample. During an interview situation with a stranger, individuals in the socially anxious group displayed increased fidgeting.

Patients with depression likewise display fidgeting behaviors (Freedman and Hoffman, 1967; Scherer et al. 2014), which also decrease over the course of successful treatment (Ulrich and Harms 1985; Lausberg and Kryger 2011). Since the comorbidity for depression and anxiety is high (47%; Stein et al. 2017), it remains unclear whether fidgeting is a specific phenomenon of SAD or depression.

One explanation for the diversity of findings is the usage of different methodologies and a notable lack of uniformity in operationalizations. The American Psychiatric Association lists “psychomotor agitation” as a motor criterion for the diagnosis of major depression in DSM-V (American Psychiatric Association 2013). Fidgeting has been defined in a diversity of ways, such as psychomotor agitation of the hands (Heerey and Kring 2007); “average acceleration from both feet” (Belak et al. 2017; p.3); “the total number of movements observed” (Farley et al. 2013; p.3), further distinguished into “head movements, appendage movements or body movements” (Farley et al. 2013; p.3) or “stammers, trembling, or fidgets” (Dow 1985). These diverse definitions and resulting operationalizations are one reason why descriptions of movement behavior in clinical settings are often vague. In turn, these different operationalizations may contribute to the contradictory results found in previous research. Moreover, fidgeting also occurs in other mental diseases and syndromes, such as eating disorders (Belak et al. 2017) or alexithymia (Lausberg et al. 2016), as well as in dysfunctional neurological states, such as patients who have experienced a concussion (Helmich and Lausberg 2019). Fidgeting, therefore, might instead be an unspecific motor phenomenon associated with mental disorders in general.

Among the fidgeting movements, those of the hands are of specific interest for diagnostic purposes during clinical interviews. Based on cinematographic and microanalysis studies, researchers differentiate between two types of hand fidgeting movements: repetitive movements and irregular movements (Lausberg 2013; Lausberg and Sloetjes 2016). Repetitive movements encompass a specific trajectory pattern. This trajectory pattern comprises three phases: a transport phase, in which the hand moves to the location where it engages in the action; a complex phase, in which the hand moves repeatedly forth and back on the same path, e.g., stroking the back of the hand; and a retraction phase, in which the hand moves back to rest position. In contrast, irregular movements have no phase structure. The hand movement starts and ends wherever the hand happens to be. These are typically small movements, and their trajectory lacks any clear spatial direction, e.g., fiddling with one’s fingers. While repetitive movements are more structured and based on a motor plan, irregular movements are unstructured and seem to happen by themselves, without any motor plan.

Irregular movements in healthy persons are associated with self-regulatory functions while speaking (Helmich et al. 2014) and with cognitive stress (Heubach 2016). The duration (seconds/unit) of irregular movements is associated with post-concussive symptoms (Helmich and Lausberg 2019). A different correlational pattern has been found for repetitive movements: Persons display them when externalizing mental concepts (Helmich et al. 2014). The duration of repetitive right-hand movements is associated with less cognitive stress during the Stroop task (Heubach 2016). Alexithymia is associated with less repetitive movements (Lausberg et al. 2016), while Korean and German dancers transport emotional expression in ballet through repetitive movements (Kim and Lausberg 2019). Fidgeting with a repetitive structure (e.g., scratching) is used to cope with stressful situations (Sousa-Poza and Rohrberg 1977; Grunwald et al. 2014). Furthermore, repetitive fidgeting has been theoretically related to self-regulation (Freedman et al. 1972; Densing et al. 2018). In mentally healthy students, fidgeting movements serve as a strategy for the successful retention of lecture material (Farley et al. 2013). Mothers’ fidgeting through contact with their infants is known to affect infants’ stress levels (Waters et al. 2017). Fidgeting as the repetitive circular or back-and-forth rubbing of the back of one hand on the other evokes neural mechanisms related to coping in the brain (Kikuchi and Noriuchi 2019). Thus, repetitive movements appear to indicate highly structured self-regulation processes, while irregular movements do not.

In the present study, a sample of outpatient psychotherapy patients’ movement behavior during the first psychotherapy session was analyzed with the behavior analysis system NEUROGES®-ELAN. The patients were diagnosed with SAD and with or without comorbid depression. The cited studies that used the NEUROGES® system to investigate movement behavior suggest a clear conceptualization involving a differentiation between repetitive and irregular movement structure. Therefore, we hypothesized that a difference in the movement structure, namely increased irregular and decreased repetitive hand movements, would be indicative of specific comorbid depressive symptoms. In movement science, Kendon (2004) proposed the definition of movement as “the articulators are moved away from some position of rest or relaxation […] and then, eventually, they are moved back again […]” (Kendon 2004; p. 11). Some of the cited studies did not differentiate among more fine-grained movement structures but rather observed movement activation according to this definition. As NEUROGES® enables the user to analyze movement activation, we decided to include an analysis of activation into this study, as well. We hypothesized no differences in hand activation between the two groups.

In the present study, comorbid depressive SAD patients exhibited more irregular movements and fewer repetitive movements than SAD patients without comorbid depression. In line with our hypotheses, the results revealed significant group differences for the specific values irregular and repetitive.

Moreover, SAD patients with comorbid depressive symptoms did not differ in overall movement activity from SAD patients without comorbid depressive symptoms. This finding provides support to the hypothesis that comorbid depression is not reflected in the total amount of motor activity, as measured by movement units with the NEUROGES® Activation category, but rather in the kind of movements, specifically the movement structure as measured in the NEUROGES® Structure category. In other words, SAD patients with comorbid depression are not hyper- or hypoactive as compared to patients without comorbid depression; however, they exhibit specific differences related to the frequency of certain movement structures.

Thus, comorbid depression in SAD patients cannot be distinguished solely by registering hyper- or hypoactivity. Instead, in line with the hypothesis that comorbid depression is associated with an increase of irregular hand movements, the present study demonstrated that SAD patients with comorbid depressive symptoms displayed more irregular movements than SAD patients without comorbid depressive symptoms. Therefore, irregular hand movements can be considered as a specific phenomenon of comorbid depression. As these movements are related to self-regulatory functions and cognitive stress (see Introduction), they probably reflect a particular depression-related emotional state. A further look at the results on the structural level revealed fewer repetitive movements in SAD patients with comorbid depression compared to SAD patients without depression. Repetitive movements are related to the externalization of mental concepts, lower cognitive stress, lower alexithymia, emotional expression in dancers, coping with stressful situations, and to self-regulation (see Introduction). Repetitive movements, therefore, indicate highly structured self-regulation processes, which are not common in patients with comorbid depression. Consequently, the present results concerning irregular and repetitive movements are consequently in line with the existing research.

However, some studies have linked irregular movements to social anxiety, not to depression (see Introduction). An explanation for these observations could be that previous studies did not consider comorbidities, and therefore unintentionally included comorbid depressive persons in their SAD samples. Kreyenbrink et al. (2017) did not differentiate SAD patients according to their comorbidities. Likewise, Heerey and Kring (2007) did not screen their participants for depression. As the probability of a comorbidity in SAD patients is 47% (Stein et al. 2017), some of the participating students could likewise have been persons with depression.

Movements with a repetitive structure are characterized by a higher degree of organization as compared to movements with an irregular structure. This higher degree of structure implies that repetitive movements are more effective at achieving an internal (or external) goal, such as copying and self-regulation, compared to irregular movements. The present findings thus enrich the results of earlier studies (Freedman and Hoffman 1967; Ulrich and Harms 1985) reporting continuous movements in patients with depression, as the present findings differentiate these movements into irregular and repetitive movements, which correlate with different depression-related and depression-unrelated mental states.

This study is the first microanalysis of fidgeting hand movements using an operationalization differentiating between irregular and repetitive movement structures. Due to the use of naturalistic data, groups in this study were not equal in size, and the resulting representative sample is small. Therefore, the results should be interpreted as preliminary. Future studies should test whether irregular movements are, in addition to depressive symptoms, associated with other disease-related features in addition to depressive symptoms, such as the outcome of the psychotherapeutic intervention.

The present results from naturalistic psychotherapy settings confirm the importance of analyzing the structure of movement behavior. Thus, the criterion “psychomotor agitation”, which is the motor criterion of the diagnosis major depression in the DSM-V, should be further specified. By taking an observer’s point of view, the psychotherapist can differentiate the patient’s movement structures during an ongoing psychotherapy session. Notably, more irregular movements and a lack of repetitive movements are present in SAD patients with comorbid depression during the first psychotherapy session. As a consequence, practitioners experienced with motor behavior observation should be able to identify correlates of depressive comorbidity in their patients during the first diagnostic interview.