Body mass index in obsessive-compulsive disorder.

•Most major psychiatric disorders are associated with overweight.•Anecdotal evidence suggests that OCD may be an exception.•We examined BMI in large samples of OCD, clinical, and non-clinical controls.•Protective factors for overweight/obesity were found in non-depressed OCD compared to controls.•Results highlight the prominent multidimensional impact of comorbid depression in OCD.