RESUMEN
One of the most common comorbidities of obsessive compulsive disorder is depression. The present study was planned to clarify the comorbidity of depression and subtypes of obsessive compulsive disorder in non-clinical samples. In this correlational study 409 students [182 males and 227 females] studying in Payam-e Noor university, branches of Tabriz, Sarab and Ardabil cities, north western part of Iran in 2008, were randomly selected and full filed Beck Depression and Padua Inventories. Data were analyzed by ANOVA and multi-variation regression tests. Uncontrollable mental activities [P<0.0001, F=l 62.27], uncontrollable motor behaviors [P<0.0001, F=l 16.21], and contamination [P<0.0001, F=89.61], subtypes were most related with depression, while checking subtype had the least relationship with depression. OCD patients with dominant obsessive thoughts are more suffering from depression, perhaps this truth leads them to less benefit from available treatments, comparing with patients who have dominant compulsions