Cannabis Use Linked to Worse Outcomes in Depression and Bipolar Disorder
A systematic review of 78 studies found cannabis use associated with increased depressive and manic symptoms, higher likelihood of developing mood disorders, and worse treatment outcomes for both major depression and bipolar disorder.
Quick Facts
What This Study Found
Cannabis use was associated with increased depressive and manic symptoms in the general population, elevated likelihood of developing both major depressive disorder (MDD) and bipolar disorder (BD), and unfavorable prognosis in people already diagnosed with either condition. The relationship held across both cross-sectional and longitudinal study designs.
Key Numbers
3,262 studies screened, 78 met criteria. Associations found with: increased depressive symptoms, increased manic symptoms, elevated risk of developing MDD, elevated risk of developing BD, unfavorable prognosis in both MDD and BD.
How They Did This
Systematic review following PRISMA guidelines. Searched EMBASE, PsycINFO, PubMed, and MEDLINE from inception through November 2023. Of 3,262 studies identified, 78 met inclusion criteria. Both cross-sectional and longitudinal designs were included.
Why This Research Matters
Cannabis is often used recreationally by people with mood disorders, and some advocate for its use as a mood treatment. This comprehensive review challenges that narrative, finding consistent associations between cannabis use and worse mood disorder outcomes across a large body of evidence.
The Bigger Picture
The finding that cannabis is associated with worse outcomes across both poles of mood disorders (depression and mania) and at both stages (development and prognosis) paints a consistent picture that challenges the self-medication hypothesis for mood conditions.
What This Study Doesn't Tell Us
The review is limited by the observational nature of most included studies. Confounders including concurrent substance use, genetics, and socioeconomic factors may explain some associations. Cannot determine whether cannabis causes mood problems or whether people with mood vulnerability are drawn to cannabis.
Questions This Raises
- ?Would specific cannabis constituents (CBD vs THC) have different effects on mood?
- ?Does the association hold at low-frequency use, or is it primarily a heavy-use phenomenon?
- ?Could cannabis withdrawal rather than cannabis use itself explain mood worsening?
Trust & Context
- Key Stat:
- Cannabis linked to worse outcomes in both depression and bipolar disorder
- Evidence Grade:
- Large systematic review with 78 studies and registered protocol, though limited by observational evidence.
- Study Age:
- 2024 systematic review
- Original Title:
- Cannabis use and mood disorders: a systematic review.
- Published In:
- Frontiers in public health, 12, 1346207 (2024)
- Authors:
- Sorkhou, Maryam(8), Dent, Eliza L, George, Tony P(23)
- Database ID:
- RTHC-05727
Evidence Hierarchy
Analyzes all available research on a topic using a structured method.
What do these levels mean? →Frequently Asked Questions
Does cannabis help or hurt depression?
This review of 78 studies found cannabis use consistently associated with increased depressive symptoms, higher risk of developing major depression, and worse treatment outcomes for people with existing depression.
Is cannabis bad for bipolar disorder?
According to this review, yes. Cannabis use was associated with increased manic symptoms, higher risk of developing bipolar disorder, and unfavorable prognosis in people already diagnosed.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-05727APA
Sorkhou, Maryam; Dent, Eliza L; George, Tony P. (2024). Cannabis use and mood disorders: a systematic review.. Frontiers in public health, 12, 1346207. https://doi.org/10.3389/fpubh.2024.1346207
MLA
Sorkhou, Maryam, et al. "Cannabis use and mood disorders: a systematic review.." Frontiers in public health, 2024. https://doi.org/10.3389/fpubh.2024.1346207
RethinkTHC
RethinkTHC Research Database. "Cannabis use and mood disorders: a systematic review." RTHC-05727. Retrieved from https://rethinkthc.com/research/sorkhou-2024-cannabis-use-and-mood
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.