Seasonal patterns in eating disorder subgroups

Patients with bulimia nervosa (BN) often have seasonal patterns of mood and appetite that compare with patterns seen in seasonal affective disorder (SAD). Seasonal patterns in other eating disorder (ED) subgroups have not been adequately described. We report on seasonal patterns in mood, weight, appetite, sleep, social activity, and energy in 154 consecutive admissions to an outpatient ED program: 60 patients with anorexia nervosa (AN), 31 with BN, 34 with a history of both AN and BN (AN/BN), and 29 with an ED not otherwise specified (ED-NOS). AN patients had significantly less seasonal variation overall than either bulimic subgroup, as measured by the global seasonality score (GSS) on the Seasonal Patterns Assessment Questionnaire (SPAQ). AN patients also showed less seasonal change in mood, weight, and energy than BN patients, and less variation in mood and appetite than AN/BN patients.