Medical marijuana acts on the endocannabinoid system – a homeostatic regulator that is present in all humans. Interestingly, research suggests that certain cannabinoids found in marijuana (i.e. THC and CBD) may have significant mood-stabilizing properties that could be beneficial for patients with the disorder.


Studies have shown that THC, under certain conditions, can have anti-anxiety, hypnotic and antidepressant effects, resulting in improvements in mood and overall well-being in normal subjects as well as in patients suffering from pain, multiple sclerosis or cancer. CBD seems to counter the psychoactive effects produced by high doses of THC and may also possess anti-anxiety, hypnotic and anticonvulsant properties of its own.

Researchers have also identified a link between marijuana use and cognitive improvements in patients with schizophrenia – a finding could explain evidence of similar improvements in bipolar disorder.

A number of recent studies have set out to determine the effects of marijuana use on patients with bipolar disorder and have provided some thought-provoking findings.

Researchers at the University of Oslo in Norway published the results of a study conducted on 133 bipolar patients. What they found was that patients who used cannabis regularly actually performed better than non-users on tests of verbal fluency and learning, although improvements in learning were not statistically significant.

In another study, researchers at the Zucker Hillside Hospital in New York, regular marijuana use was linked to higher levels of attention, processing speed and memory among the 200 bipolar patients that the researchers followed over a 9 year span.

On the other hand, while these results suggest that marijuana use might improve cognitive function in cases of bipolar disorder, a study published found that bipolar patients who used cannabis exhibited less treatment compliance as well as higher levels of illness severity, mania and psychosis, although data was only collected over a 12 month period.

Interestingly, the study also found that while cannabis users were less likely to have a relationship and were less satisfied with life in general, they were still more engaged in social activities than non-users. Furthermore, the study identified no significant differences between cannabis use and independent living or work impairments.