The relationship between self-control and symptoms of anxiety and depression in patients with eating disorders: a cross-sectional study including exploratory longitudinal data.

Background: Personality style can partly be described as the way an individual controls and regulates emotions and can be divided into over- and undercontrol. Studies have indicated that personality style may impact the onset, clinical presentation, and recovery from an eating disorder (ED). Furthermore, symptoms of anxiety and depression are common in patients with EDs. However, the association between self-control levels and anxiety/depression symptoms in patients with EDs remains unknown. The main aim of this study was to assess how levels of self-control relate to anxiety/depression symptoms in patients with EDs, with a secondary, exploratory aim to assess the stability of self-control during treatment.

Methods: Patients were recruited from the outpatient ED clinic at the Uppsala University Hospital, between October 2014 and December 2019. In total, 227 patients (age: 25.4, SD: 7.1) were included at the start of their treatment, with 14 participants also completing post-treatment measurements. Self-control was assessed with the Ego Undercontrol scale (EUC-13), anxiety/depression symptoms with the Hopkins Symptoms Checklist (HSCL-25), and ED diagnosis and symptoms with the Eating Disorder Examination Interview (EDE-I) and Questionnaire (EDE-Q), respectively.

Results: A quadratic regression (n = 227) showed that levels of self-control accounted for about four percent of the variance in degree of global anxiety/depressive symptoms. Anxiety/depression symptoms were better explained by ED symptoms (R = 0.24). Visualizations in boxplots revealed a tendency for extreme values of both over- and undercontrol to be associated with higher levels of depression, whereas symptoms of anxiety increased with increasing undercontrol. In the exploratory analyses (n = 14) levels of self-control remained more stable than symptoms of anxiety and depression, which decreased significantly during ED treatment.

Conclusions: Our results indicated that anxiety/depression symptoms, in patients with EDs, were not strongly correlated with levels of self-control, but rather with ED symptoms. However, extreme values of both over- and undercontrol showed a tendency to be associated with higher levels of depression symptoms, whereas anxiety symptoms increased with increasing levels of undercontrol. Future studies could benefit from considering both over- and undercontrol as potentially dysfunctional.