Cannabis Use in Bipolar Disorder Presents a Treatment Challenge

In some patients, cannabis use can complicate the management of bipolar disorder by causing mood instability and psychosis. Other patients believe it helps manage their moods.

Among patients with bipolar disorder, cannabis is the most commonly abused drug. Lifetime use of cannabis among bipolar patients is estimated to be around 70%, and 30% present a comorbidity of cannabis abuse or dependence. The risk for psychotic disorders increases with the frequency and intensity of cannabis use. Researchers have found that cannabis use is also associated with a younger age at onset of first manic episode, increased manic and depressive episodes, increased risk of rapid cycling, poorer outcome, and poorer treatment compliance.1

These findings illuminate the challenges in treating patients with bipolar disorder who use cannabis, especially as an increasing number of US states legalize marijuana. Self-medication with cannabis was recently found to be 3.73 percentage points higher among those living in states with medical marijuana laws.2 Although further investigations are needed to clarify the relationship between mania onset and cannabis use, researchers say they are “undeniably correlated.”1

Psychiatry Advisor spoke with Girish Subramanyan, MD, a psychiatrist in full-time private practice in San Francisco, California, specializing in the treatment of adults with mood and anxiety disorders, including treatment-resistant mood and anxiety disorders.

Psychiatry Advisor: Does cannabis use present any challenges in treating patients with bipolar disorder? If so, what are the challenges and how do they affect treatment? 

Dr Girish Subramanyan: Yes. It can complicate the management of bipolar disorder by virtue of causing mood instability and psychosis in certain patients with bipolar disorder. Cannabis is a known psychotogenic drug for some people, although the majority of people who use it do not develop psychosis. But, among those that do, there seems to be a higher risk for conversion to schizophrenia and bipolar disorders, unfortunately. Moreover, it’s not uncommon for me to see patients with bipolar disorder relapse into mania with recent cannabis use. Observational studies have demonstrated a correlation between cannabis use and hypomanic and manic relapse in bipolar disorder.

Psychiatry Advisor: Are there distinct challenges or effects of cannabis use in patients with bipolar I vs bipolar II? 

Dr Subramanyan: Yes. The possibility of cannabis contributing to manic relapse in bipolar I disorder makes it potentially more dangerous in bipolar I disorders. Manias have the potential to cause devastating consequences in the lives of patients and their families. Plus, there is a real possibility that cannabis can contribute to psychotic manic episodes. This risk is probably lower in individuals with bipolar II disorder, but it is possible, I suppose, that someone with a true diagnosis of bipolar II disorder could have a cannabis-induced manic episode with psychotic features, something that may never have occurred spontaneously for this individual.

In bipolar II disorder, you may end up seeing more mood instability, mixed states, and hypomanic episodes, and although these states are uncomfortable, and even dangerous, if they are accompanied by suicidal ideations, they generally don’t do as much damage as full-blown manic episodes.

Psychiatry Advisor: Has the legalization of recreational marijuana use in California had any noticeable effect on your treatment of bipolar disorder?

Dr Subramanyan: Surprisingly, I don’t think I’ve seen much in the way of increased incidence of mania or psychosis in my practice since the legalization of recreational marijuana in California. What I have noticed, however, is that more and more patients in my practice are using some kind of cannabinoid for a variety of reasons: treatment of anxiety, treatment of pain, treatment of insomnia, etc. Patients seem to be using cannabidiol (CBD) products, in particular, more frequently. CBD is interesting in that it seems to have opposite effects in the brain as does THC. There is a thought that it could actually have antipsychotic function.

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Psychiatry Advisor spoke with customers of Southwest Patient Group, a San Diego marijuana dispensary.

Amanda Hasten: I was diagnosed with dipolar disorder at age 12. I always knew I was different because, one minute I’d be happy, [the] next minute I was crying, and then it all became too much and I ended up trying to commit suicide at 14. I was prescribed all kinds of medication, but nothing seemed to work. At the age of 16 years, I began smoking marijuana and my life was changed. No longer do I have these constant mood changes, and my mind doesn’t run a mile a minute with dread and fear. I have a medical marijuana card now as an adult, and I am grateful to the marijuana industry for saving my life.

Nicholas G.: I have been struggling with and managing my manic and depressive episodes since 2004. I experience a lesser form of mania called hypomania, which means that although I may not experience grandiosity or psychosis like those with a bipolar 1 diagnosis, my behaviors are impulsive and have lasting consequences. This has cost me educational and professional opportunities, relationships, and even a bankruptcy. When I am on my prescribed meds I am able to reduce the frequency and severity of my manic and depressive episodes, but they will never completely go away.

I began using cannabis as a senior in high school. I increased my cannabis use as an undergrad when, unbeknownst to me, I began using cannabis to self-medicate. I had never seen a psychiatrist and knew little about mental health, but I did notice that smoking indica-heavy cannabis helped me sleep better and was one of the only methods I had ever discovered that slows my manic thoughts to a manageable level (which is why I stay far away from anything sativa, as that accelerates my thinking and makes things much worse). I used cannabis to stimulate my appetite when depression and anxiety made it too difficult to eat, and as a common activity with friends to help maintain a supportive network of friends. I stopped using cannabis completely for 6 years after I was initially diagnosed and stabilized on psychotropic medication. Unfortunately, once…I lost my insurance and was no longer able to afford to see my psychiatrist or pay for my medications…I turned back to cannabis to help manage my symptoms. The psychotropic medications are essential for me to maintain stable mental [health], but cannabis helps make things a little softer and more manageable.


  1. Bally N, Zullino D, and Aubry JM. Cannabis use and first manic episode. J Affect Disord. 2014;165,103-108.
  2. Sarvet AL, Wall MM, Keyes KM, et al. Self-medication of mood and anxiety disorders with marijuana: higher in states with medical marijuana laws. Drug Alcohol Dependence. 2018;186,10-15.