More than half of people with bipolar will qualify for a substance use disorder diagnosis at some point. In many places, the most popular drug (other than alcohol) in people with bipolar is cannabis.
People with bipolar are almost 7 times as likely to use cannabis than the general population.
In the United States, many states have legalized cannabis for medical indications, and two states have legalized its recreational use.
I happen to live in one of the states that legalized medical marijuana (California) and have had lots of experience with people with bipolar using marijuana.
Many studies show that, in bipolar disorder, cannabis use is associated with an earlier age of onset, greater illness severity, more time spent in manic/mixed episodes, more psychotic symptoms, more rapid cycling, poorer life functioning, and poor adherence to prescribed treatments.
Overall, the evidence is clear that cannabis is likely to worsen the course of bipolar.
What happens when someone with bipolar stops using marijuana?
A recently published study, based on data from a large, ongoing, study (the European Mania in Bipolar Longitudinal Evaluation of Medication (EMBLEM) study) looked at this question.
This is a large study, with over 1922 people being followed. Of these people, 88.5% had never used cannabis, 6.9% were current users, and 4.6% were previous users.
The main finding of the study is that previous users had outcomes similar to those of never users.
However current users had significantly lower rates of recovery and remission, higher rates of recurrence, greater work impairment, and a lower likelihood of living with a partner than never users.
Although many people in California can find doctors who will prescribe marijuana as a “treatment” for mania, the evidence is overwhelming that marijuana makes things worse.
- Zorilla I, Aguado J, Haro JM, et al. Cannabis and bipolar disorder: does quitting cannabis use during manic/mixed episode improve clinical/functional outcomes? Acta Psychiatri Scand 2015;131:100-110.
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