The potential of psychedelic treatments for OCD is gaining traction, while cannabis remains a less effective option, according to a recent review. Dr. Michael Van Ameringen, a psychiatry professor at McMaster University, Canada, led the study published in the Journal of Psychiatric Research. He found that a significant portion of OCD patients (40-60%) experience only partial or no relief from conventional treatments like SSRIs and exposure and response prevention therapy. This has sparked interest in exploring alternative therapies, with psychedelics and cannabinoids emerging as potential candidates.
The review highlights a scarcity of published literature on the efficacy of these substances for OCD. To address this, Van Ameringen included conference presentations and preliminary, unpublished findings in the review. The findings revealed a stronger signal for the effectiveness of psychedelics, particularly psilocybin (the active compound in 'magic mushrooms'), compared to cannabinoids like THC and CBD.
Van Ameringen's theory suggests that the difference lies in how these substances interact with brain regions associated with OCD. Cannabinoids activate CB1 receptors, which regulate compulsions and anxiety, but they don't provide long-lasting relief from OCD symptoms. In contrast, psilocybin reduces connectivity in the brain's default mode network, which is heavily involved in self-referential thinking and rumination, common in OCD.
Dr. Mohamed Sherif, a psychiatrist and computational neuroscientist, believes that the methodology of cannabis and psilocybin studies may contribute to the varying results. Psychedelic clinical trials often encourage patients to view their experience as a therapeutic journey, which is not typically the case with cannabis studies. Dr. Terrence Ching, a clinical psychologist, also suggests that the way people use these substances might explain the different outcomes.
Ching's clinical trial on a single dose of psilocybin for OCD showed promising results, with psilocybin proving more effective than a placebo. The trial's unique approach, including strict rules on touch and a focus on non-directive, non-judgmental facilitation, allowed patients to gain deeper insights into their OCD. Ching's findings emphasize the importance of understanding the nature of OCD and the need for control, which are core features of the disorder.
Despite the potential of psychedelic medications, challenges persist. Psilocybin remains an illegal Schedule I substance in the US, requiring researchers to navigate additional regulatory hurdles. The issue of 'functional unblinding' also poses a challenge, as participants may be able to guess whether they received psilocybin or a placebo, potentially affecting their perception of symptoms. Ching stresses the need to treat psychedelics with the same seriousness as other medications and to conduct research ethically and rigorously.
