Can Marijuana Help Your Bipolar Disorder?

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My good friend John McManamy has written a thoughtful blog about the possible use of medical marijuana as a treatment for mania. I honestly think the risks outweigh any possible benefits, but the topic is worth discussing.

In 2010 I reported on a study looking for links between cannabis and the development of psychosis and bipolar. And back in 2005 a Dutch study found that marijuana use doubled the risk of developing schizophrenia.

Since both bipolar depression and mania can have psychotic features, there is at least some evidence that even medical marijuana use might have negative effects in people with bipolar disorder.

Studies Show Links to Worse Outcomes

Medical research shows that cannabis use in people with psychosis (but not necessarily bipolar) is associated with an earlier age of their first psychotic episode. It's also associated with manic symptoms and with problems thinking.

In one study, patients who quit using marijuana or reduced its use following their first psychotic episode had the greatest improvement in symptoms at the one year mark, compared both to continuing cannabis users and people who had never used cannabis.

Long-term cannabis use may have a negative effect on long-term clinical outcomes for those with bipolar spectrum disorders, as well.

A 2015 study found lower bipolar disorder remission rates for current regular cannabis users (those who used it three times a week or more often) and those who regularly smoke tobacco when compared to people who don't use either substance.

That study, which lasted two years, concluded that regular marijuana users who also have bipolar don't do as well long-term as people who don't use the drug.

Another study looked at the short-term effects of cannabis use in people with bipolar disorder, and concluded that the drug was associated with both manic and depressive symptoms.

However, that study couldn't find evidence that people with bipolar were using cannabis to self-medicate on a regular basis.

Now, none of these studies prove that cannabis is actually causing these problems in people with bipolar — they just show an association between marijuana use and problems. But you should factor this information into your thinking when deciding whether to use cannabis.

Marijuana: Substance Abuse Risk?

All drugs have risks and side effects, and cannabis is no exception.

As McManamy says in his blog, substance abuse is quite prevalent among those with bipolar disorder. People have used alcohol and drugs to try to control their systems in great numbers, and may reduce their likelihood of successful treatment of their bipolar as a result.

By using marijuana to self-medicate for bipolar disorder, you run the risk of gaining a second diagnosis in addition to your bipolar diagnosis: substance abuse.


Kim SW et al. Impact of Cannabis Use on Long-Term Remission in Bipolar I and Schizoaffective Disorder. Psychiatry Investigation. 2015 Jul;12(3):349-55.

Mané A et al. Relationship between cannabis and psychosis: Reasons for use and associated clinical variables. Psychiatry Research. 2015 Sep 30;229(1-2):70-4.

Stone JM et al. Cannabis use and first-episode psychosis: relationship with manic and psychotic symptoms, and with age at presentation. Psychological Medicine. 2014 Feb;44(3):499-506.

Tyler E et al. The relationship between bipolar disorder and cannabis use in daily life: an experience sampling study. PloS One. 2015 Mar 4;10(3):e0118916.

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