Season of birth and eating disorders: patterns across diagnoses in a specialized eating disorders service.

OBJECTIVE: In view of inconsistent findings from previous studies, the aim was to investigate possible seasonal variation in month of birth in patients with anorexia nervosa, bulimia nervosa, and eating disorder not otherwise specified.

METHOD: We examined the month of birth in a cohort of 1,305 adult patients with a DSM-IV eating disorder diagnosis at first presentation to a specialized eating disorders service.

RESULTS: When compared to general population data, we found no evidence of significant variation in month or season of birth in anorexia nervosa, bulimia nervosa, or eating disorder not otherwise specified.

CONCLUSION: The authors question whether people who develop eating disorders differ from the general population in their season of birth. Caution is expressed about further speculation regarding the etiological significance of season of birth in eating disorders.