A recent review of alternative treatments for obsessive-compulsive disorder (OCD) shows that psychedelic treatments show promise for treating the disorder, but cannabis does not.
Dr. Michael Van Ameringen, professor of psychiatry at McMaster University in Ontario, Canada, and lead author of the review published in the Journal of Psychiatric Researchstated that 40-60% of patients with OCD either receive partial relief or no relief using available treatments, including SSRIs and exposure and response prevention therapy.
While psychedelics and cannabinoids have become part of the conversation about OCD—a disorder characterized by obsessive, obsessive thoughts and/or compulsive behavior—there is much more published data on the effectiveness of these substances for more common conditions such as depression and anxiety.
“We wanted to clarify and really understand, is there evidence that these things that have been talked about can be used as the next step in treatment?” Van Ameringen explained.
Given the paucity of existing literature, Van Ameringen said he doesn't know what to expect. To compensate for the lack of published information, he included conference presentations and preliminary, unpublished findings in the review article.
Gathering the available evidence, Van Ameringen and his team found “stronger signals” about the effectiveness of psychedelics, particularly psilocybin (the psychoactive component of magic mushrooms), than cannabinoids such as THC and CBD.
Van Ameringen suggests the difference has to do with how these substances interact with areas of the brain associated with OCD. Although cannabinoids activate the brain's CB1 receptors, which regulate symptoms such as compulsions and anxiety, available evidence suggests they do not provide long-lasting relief from OCD symptoms.
Psilocybin, on the other hand, may reduce connectivity in the brain's default mode network, which is “essentially involved in self-referential thinking and rumination. The default mode network is really activated in OCD,” he says.
Differences in research methodology between cannabis and psilocybin may also have contributed to the different results, says Dr. Mohamed Sherif, a psychiatrist and computational neuroscientist at Brown University who will lead a future clinical trial of psilocybin for obsessive-compulsive disorder. Psychedelic clinical trials like the ones Sherif is planning typically offer patients not only medication, but encourage them to frame their experience as a therapeutic “journey.”
“This has not been done with cannabinoids [studies,]— the Sheriff explained.
Dr. Terrence Ching, a clinical psychologist at Yale School of Medicine, also wondered whether the way people use cannabis versus psilocybin might explain the different results. Although people tend to use cannabis for temporary relief, psilocybin can promote real changes in the brain and in patients' perception of their OCD.
“Cannabis can be used for the same therapeutic reason, to confront something deeper about your OCD or your obsessive fears. But traditionally, people tend to use cannabis for the avoidance function,” Ching explained.
Preliminary results from Ching's clinical trial of a single dose of psilocybin for OCD were included in Van Ameringen's review article and showed that psilocybin was effective for OCD symptoms compared to placebo. Ching is now preparing the study for publication and is planning a second clinical trial in which patients with OCD will receive two doses of psilocybin at different times.
During the single-dose study, each of the 11 patients received psilocybin or niacin, a placebo designed to mimic some of the effects of psilocybin so that patients would not be sure which drug they received. During dosing sessions, patients sat with two facilitators who offered minimal guidance in the form of open-ended questions.
Ching said his protocol includes strict rules about the type of touch that is allowed if patients request it (hand on the shoulder or forearm only) to create clear ethical boundaries. Past psychedelic clinical trials caused controversy when the hosts initiated unwanted touching of participants who were intoxicated.
Ching said the study was useful not only for showing that psychedelics can improve OCD symptoms, but also for teaching more about the nature of OCD for both clinicians and the participants themselves.
According to Ching, psilocybin is known for inducing “mystical experiences,” characterized by a specific type and intensity of psychedelic effects.
“What we see with OCD most often are partial mystical experiences. People kind of hit the brakes when they sense that psilocybin wants to take them into a deeper state of experience,” Ching said, adding that this highlights one of the core features of the disorder—the need to be in control.
While clinicians involved in psychedelic research can usually encourage patients to go deeper, Ching said it's important to remain “non-directive and non-judgmental” with OCD patients.
In Ching's study, he saw patients become aware of their own resistance to the drug and gain a deeper understanding of their need for control, saying things like, “I do realize that this is how I've approached the unknowable things in my life, but that's life. Life is full of unknowable things.”
Ching is hopeful about the future of psychedelic drugs, but there are a number of obstacles that make their research difficult. Psilocybin is still an illegal Schedule I substance in the US, meaning researchers must take additional steps to study it, including working with a DEA representative and using a DEA-approved safe that “must be secured to the ground” in a separate, windowless room.
Researchers must also address the issue of “functional blindness,” or the fact that psychedelic effects may mean that study participants may guess whether they received psilocybin or a placebo, which could change their perception of their own symptoms. This is especially problematic given the hype surrounding psychedelics, Ching said.
Many participants will enter the trial expecting a “miracle cure,” a narrative that Ching believes is actually harmful to psychedelic research: “What we need to do now is take psychedelics seriously, like any other medicine worthwhile, do the research in a controlled, rigorous, ethical way, honoring the traditional indigenous users of psychedelics, because they are there, and there is great wisdom in that too.”
