Cannabis may reduce acute OCD symptoms, but long-term effects unclear
By Rich Haridy
October 20, 2020


New research from WSU is among the first to investigate real-world uses of cannabis to treat symptoms of OCD
TeriVerbickis/Depositphotos


Research from Washington State University (WSU), and published in The Journal of Affective Disorders, is reporting some people find their symptoms of obsessive-compulsive disorder (OCD) dramatically drop after smoking cannabis. The study suggests the improvements may only be beneficial in the short-term, and more research is necessary to understand the long-term effect of cannabis use on OCD.

Despite the broad interest in cannabis’ therapeutic effects over recent years there has been surprisingly little study focusing specifically on the drug’s relationship with OCD. The results from very first placebo-controlled study on the subject, published earlier this year, found smoking cannabis had the same effect on OCD symptoms as a placebo. However, several animal studies have found doses of CBD may inhibit certain compulsive behaviors.

This new WSU study is not a controlled clinical trial, but instead it relies on self-reported user data gathered by a smartphone app called Strainprint. This Canadian app was designed to offer personalized information for patients, enabling real-time tracking of medical symptoms against specific strains of cannabis.

In this case, subjects can report the severity of their OCD symptoms, before and after cannabis use, offering researchers a way to follow the efficacy of cannabis as a treatment in real-time, and in relation to the varying THC or CBD levels from strain to strain. The WSU team has produced three prior studies analyzing Strainprint data, most notably finding many cannabis users self-administer the drug to treat severe headaches and migraines.

The new study tracked data from 87 subjects with OCD symptoms using the Strainprint app. Over 31 months these subjects logged more than 1,800 cannabis sessions, allowing the researchers to infer valuable long-term use data, as well as examining the shorter, more acute effects.

OCD symptoms were divided into three categories (intrusions, compulsions, and anxiety), with each user rating their symptoms from 0 to 10, both before and after a cannabis session. Overall, the study found subjects reported a 60 percent drop in compulsions, a 49 percent drop in intrusions, and a 52 percent drop in anxiety from before to after smoking cannabis.

Reductions in OCD symptoms relating to compulsions and anxiety remained relatively stable over time, but reductions in intrusions seemed to grow smaller with continued cannabis use. The researchers hypothesize a tolerance to the effects of cannabis may build with long-term use.

“The results overall indicate that cannabis may have some beneficial short-term but not really long-term effects on obsessive-compulsive disorder,” explains Carrie Cuttler, corresponding author on the new study. “To me, the CBD findings are really promising because it is not intoxicating. This is an area of research that would really benefit from clinical trials looking at changes in compulsions, intrusions and anxiety with pure CBD.”

The Strainprint app tracks THC and CBD concentrations in particular strains of cannabis, allowing the researchers to effectively investigate whether cannabinoid levels influence symptomatic outcomes. As Cuttler indicates, the study reveals a distinct correlation between higher CBD levels and greater drops in compulsive OCD symptoms.

This finding certainly gels with earlier animal studies investigating compulsive behavior and CBD, however more targeted human trials are necessary to validate them.

The study is clear to note a number of caveats with this kind of self-reported study, particularly referencing what is called the “expectancy effect” whereby the Strainprint users' positive responses are potentially driven by prior expectations about the benefits of CBD in relation to OCD.

Sampling bias is another particular caveat cited in the study, limiting any broad conclusions about the efficacy of cannabis treating OCD symptoms.

“Specifically, it seems likely that the sample predominantly comprises individuals who find cannabis effective in managing their symptoms,” the researchers write in the study. “Individuals who find it ineffective and/or who do not tolerate its side effects would likely stop using cannabis and the app to track such use. This is further supported by evidence of individual differences in the efficacy of cannabis in reducing symptoms.”

None of this means the study is entirely useless. The researchers note the unique nature of the Strainprint app allows for extraordinary insights into real-world uses of cannabis. And despite the self-reported nature of the data, the ability to track the effect of the drug in single users over long periods of time offers researchers novel perspectives.

The ultimate conclusion of the new study is that cannabis may offer those with OCD some level of acute symptomatic relief in the short-term but there is evidence those benefits can diminish over time. And, the long-term effect of cannabis on OCD is still profoundly unclear.

The new research was published in The Journal of Affective Disorders.

Source: Washington State University