Additional Study Information: The purpose of this pilot research study is to test whether certain components of the marijuana plant, known as "cannabinoids", may help to reduce symptoms in patients with OCD. Specifically, patients enrolled in the study will smoke marijuana containing different concentrations of 2 different cannabinoids, THC and CBD. Both of these agents act on the brain's "endocannabinoid system," which has been hypothesized to play a role in OCD. Neither compound is currently FDA-approved for treating OCD.