SAT-441 Oxytocin Levels Are Associated with Psychopathology in Restricting but Not Binge-Purge Subtype of Anorexia Nervosa

Objective: Anorexia nervosa (AN), a psychiatric disorder characterized by food restriction and distorted body image, is associated with depression, anxiety, and social-emotional functioning deficits. Basal levels of oxytocin, an anorexigenic hormone with antidepressant, anxiolytic, and prosocial properties, are low in women with AN, and a relationship between low oxytocin levels and psychopathology when examined across AN and healthy control groups has been established. We aimed to determine whether oxytocin levels in AN are related to psychopathology, and whether AN subtype (restrictive food intake alone [AN-R] vs. restriction plus binge and/or purge behaviors [AN-BP]) impacts this relationship. Methods: We performed a cross-sectional study of 39 women with AN (age [mean±SEM]: 28.3±8.3 years; BMI: 18.5±1.7 kg/m(2); 23 AN-R, 16 AN-BP). We obtained fasting serum oxytocin levels and self-report measures for psychopathology (Eating Disorder Examination Questionnaire [EDE-Q], Beck Depression Inventory-IA [BDI-IA], State-Trait Anxiety Inventory – Trait scale [STAI-T], Dimensional Assessment of Personality Pathology – Basic Questionnaire [DAPP-BQ], Liebowitz Social Anxiety Scale [LSAS], Toronto Alexithymia Scale [TAS-20], and Interpersonal Support Evaluation List [ISEL]). Results: Oxytocin levels and psychopathology scores did not significantly differ in AN-R vs. AN-BP. In AN-R but not AN-BP, oxytocin levels were negatively associated with disordered eating psychopathology (EDE-Q global score: r(s)=−0.54, p=0.012), depressive and anxiety symptoms (BDI-IA: r(s)=-0.63, p=0.003; STAI-T: r(s)=−0.68, p=0.001), and social-emotional symptoms (DAPP BQ Suspiciousness: r(s)= -0.48, p=0.03; LSAS social fear: r(s)= -0.71, p=0.0004; LSAS public fear: r(s) = -0.40, p=0.046; LSAS social avoidance: r(s)= -0.66, p=0.0016; LSAS public avoidance: r(s) = -0.54, p= 0.014; TAS-20 total score: r(s)= -0.45, p=0.049). In both AN-R and AN-BP, oxytocin levels were positively associated with perceived social support (ISEL total score: r(s) =0.6, p=0.004 in AN-R; r(s) =0.52, p=0.046 in AN-BP). Conclusions: Low oxytocin levels are associated with severity of psychopathology in AN-R but not AN-BP, suggesting divergent underlying neurobiology.