Cannabis use may worsen illness course in bipolar disorder

By Mark Cowen, Senior medwireNews Reporter

Cannabis use disorder (CUD) is associated with a more severe illness course among patients with bipolar disorder (BD), researchers report.

Shaul Lev-Ran (Centre for Addiction and Mental Health, Toronto, Ontario, Canada) and colleagues also found that BD patients with co-occurring CUD were more likely than those without to use other substances and have antisocial personality disorder.

The researchers studied data on 1905 individuals, aged 18 years and older, with BD who participated in the National Epidemiological Survey of Alcohol and Related Conditions (NESARC) 2001-2002, which comprised a nationally representative sample of 43,093 individuals.

Overall, 7.2% (n=119) of BD patients fulfilled criteria for DSM-IV-defined CUD in the previous 12 months compared with 1.2% of NESARC participants without the mood disorder.

Among individuals with BD, those with co-occurring CUD (n=119) were mostly men (62%), aged 18-29 years (70%), high-school educated (67%), unmarried (57%), and living in a rural area (60%).

After accounting for age, gender, and other sociodemographic variables, the team found that patients with BD and co-occurring CUD were at increased risk for nicotine dependence (adjusted odds ratio (AOR)=3.8), alcohol use disorder (AOR=6.6), any drug disorder (AOR=11.9), and any personality disorder (AOR=2.36), compared with BD patients without CUD (n=1786).

BD patients with co-occurring CUD also had a significantly higher median number of mood episodes per year than other BD patients, at 1.8 versus 0.7, as well as an earlier age at onset of a first manic (19.5 vs 25.1 years) or depressive (18.5 vs 24.4 years) episode.

Lev-Ran et al conclude: "Co-occurring CUD is associated with significant co-morbidities and a more severe course of illness among individuals with bipolar disorder."

They suggest: "Comprehensive evaluation of patients with bipolar disorder (especially males) should include a systematic assessment of substance use disorders, including CUD."

Licensed from medwireNews with permission from Springer Healthcare Ltd. ©Springer Healthcare Ltd. All rights reserved. Neither of these parties endorse or recommend any commercial products, services, or equipment.


  1. Matt Riley Matt Riley Australia says:

    What garbage, this study is looking to find problems to report about cannabis use, not scientifically trying to see what's going on. The cannabis use is because of the bipolar disorder in the vast majority of cases. Effectively your study means very little which is of any consequence but none the less it sends a message to everyone who reads it that cannabis is bad, be scared of it. This type of fear mongering serves no benefit to society. It continues an entrenched prejudice against cannabis users in society. A prejudice which allows cannabis prohibition to continue despite the fact that cannabis prohibition causes far more damage to peoples lives than cannabis ever has or ever will.

    Why is it that none of these studies ever look at the benefits that the cannabis users feel they receive from their cannabis use? Simple, there is prejudice. This is why society allows cannabis users to be discriminated against in so many ways. Employment opportunities lost, careers destroyed on the basis of a urine test with no actual workplace incident or problem occurring, police harassment and the threat of the criminal justice system. Stigma and attitude from people in society, nasty looks from neighbours. Isolation in the community, a loss of support networks. Family breakdown and discrimination against cannabis users in the family court. All of these things hurt cannabis users. Cannabis users are people. People make up society.

    Your article is supporting a system that creates prejudice to keep pharmaceutical companies profitable and it does so at the societies cost. Grow a conscience.

  2. Shana Rosenberg Shana Rosenberg United States says:

    The headline and article as written is meaningless and wrong. People with a worse course of bipolar disorder do often have comorbid personality disordered behavior (sometimes not deserving the diagnosis but instead better medical care) and comorbid "substance abuses" such as cannabis, alcohol, and nicotine. If anything this headline should be "Severe Bipolar Disorder Causes Comorbid Cannabis Use Disorder".

  3. La Ella La Ella United States says:

    is CUD a DSM-IV or DSM-V defined term or diagnosis? I dont think so.... Anyway brings up an excellent point regarding self medicating and BD. Im more intrigued to see a physiologic standpoint on this issue.

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News Medical.
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