“Background: Little is known about the the acute effects of cannabis on symptoms of OCD in humans. Therefore, this study sought to: 1) examine whether symptoms of OCD are significantly reduced after inhaling cannabis, 2) examine predictors (gender, dose, cannabis constituents, time) of these symptom changes and 3) explore potential long-term consequences of repeatedly using cannabis to self-medicate for OCD symptoms, including changes in dose and baseline symptom severity over time.

Results: Patients reported a 60% reduction in compulsions, a 49% reduction in intrusions, and a 52% reduction in anxiety from before to after inhaling cannabis. Higher concentrations of CBD and higher doses predicted larger reductions in compulsions. The number of cannabis use sessions across time predicted changes in intrusions, such that later cannabis use sessions were associated with smaller reductions in intrusions. Baseline symptom severity and dose remained fairly constant over time.

Conclusions: Inhaled cannabis appears to have short-term beneficial effects on symptoms of OCD. However, tolerance to the effects on intrusions may develop over time.”

https://pubmed.ncbi.nlm.nih.gov/33049434/

“Inhaled cannabis reduced the severity of compulsions by 60% and intrusions by 49%.”

https://www.sciencedirect.com/science/article/abs/pii/S0165032720328202?via%3Dihub