Low Fasting Oxytocin Levels Are Associated With Psychopathology in Anorexia Nervosa in Partial Recovery

Objective: Anorexia nervosa (AN), a psychiatric disorder characterized by restriction of food intake despite severe weight loss, is associated with increased comorbid anxiety and depression. Secretion of oxytocin, an appetite-regulating neurohormone with anxiolytic and antidepressant properties, is abnormal in AN. The link between oxytocin levels and psychopathology in AN has not been well explored.

Methods: We performed a cross-sectional study of 79 women aged 18-45 years (19 AN, 26 AN in partial recovery [ANPR], and 34 healthy controls [HC]) investigating the relationship between basal oxytocin levels and disordered eating psychopathology, anxiety, and depressive symptoms. AN diagnoses were based on DSM-5 criteria. Data acquisition took place between December 2008 and March 2014. Fasting serum oxytocin levels were obtained, and the following self-report measures were used to assess psychopathology: Eating Disorder Examination Questionnaire, State-Trait Anxiety Inventory, and Beck Depression Inventory-II.

Results: Fasting oxytocin levels were low in ANPR compared to HC (P = .0004). In ANPR but not AN, oxytocin was negatively associated with disordered eating psychopathology (r = −0.39, P = .0496) and anxiety symptoms (state anxiety: r = −0.53, P = .006; trait anxiety: r = −0.49, P = .01). Furthermore, ANPR with significant disordered eating psychopathology, anxiety symptoms, or depressive symptoms had lower oxytocin levels compared to those with minimal or no symptoms (P = .04, .02, and .007, respectively).

Conclusions: We speculate that a dysregulation of oxytocin pathways may contribute to persistent psychopathology after partial weight recovery from anorexia nervosa.