Regular Cannabis Use Linked to Better Decision-Making in People With Bipolar Disorder

People with bipolar disorder who used cannabis regularly showed decision-making and daily functioning comparable to healthy non-users, while cannabis impaired decision-making in healthy people.

Miranda, Alannah et al.·Translational psychiatry·2025·Preliminary EvidenceObservational
RTHC-07147ObservationalPreliminary Evidence2025RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Observational
Evidence
Preliminary Evidence
Sample
N=87

What This Study Found

Among 87 participants, people with bipolar disorder who used cannabis regularly (4+ times/week) performed comparably to healthy non-users on decision-making and functional capacity measures. In contrast, healthy participants who used cannabis showed impaired decision-making. Non-using bipolar participants performed worst.

Key Numbers

N=87. Four groups compared. Bipolar cannabis users matched healthy non-users on Iowa Gambling Task and UPSA-2 scores. Cannabis use defined as 4+ times per week.

How They Did This

Observational study comparing 87 participants across four groups (healthy cannabis users, healthy non-users, bipolar cannabis users, bipolar non-users) on the Iowa Gambling Task and UCSD Performance-based Skills Assessment.

Why This Research Matters

This counterintuitive finding suggests cannabis may have different cognitive effects depending on underlying brain conditions, potentially normalizing disrupted decision-making circuits in bipolar disorder.

The Bigger Picture

This challenges the assumption that cannabis uniformly impairs cognition. If cannabis normalizes decision-making in bipolar disorder while impairing it in healthy brains, this could reflect fundamentally different underlying neurochemistry.

What This Study Doesn't Tell Us

Small observational sample cannot establish causation. Selection bias: bipolar patients who use cannabis regularly may differ in important ways from those who do not. Cross-sectional snapshot does not capture long-term trajectories.

Questions This Raises

  • ?Does cannabis genuinely improve bipolar cognition, or are higher-functioning bipolar patients more likely to use cannabis?
  • ?Could cannabinoid-based treatments be developed specifically for bipolar cognitive deficits?

Trust & Context

Key Stat:
Bipolar cannabis users matched healthy non-users on decision-making tasks
Evidence Grade:
Small observational study with important selection bias concerns. Intriguing but needs replication in larger, controlled studies.
Study Age:
2025 study with novel findings on cannabis-bipolar cognitive interactions.
Original Title:
Chronic cannabis use in people with bipolar disorder is associated with comparable decision-making and functional outcome to healthy participants.
Published In:
Translational psychiatry, 15(1), 506 (2025)
Database ID:
RTHC-07147

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study

Watches what happens naturally without intervening.

What do these levels mean? →

Frequently Asked Questions

Can cannabis help with bipolar disorder symptoms?

This study found regular cannabis users with bipolar disorder performed as well as healthy non-users on decision-making tests, while bipolar non-users performed worse. However, the small sample and observational design mean this could reflect selection effects rather than a true treatment benefit.

Does cannabis affect everyone's cognition the same way?

No. This study found cannabis was associated with impaired decision-making in healthy participants but comparable or improved performance in those with bipolar disorder, suggesting the effects depend on underlying brain chemistry.

Read More on RethinkTHC

Cite This Study

RTHC-07147·https://rethinkthc.com/research/RTHC-07147

APA

Miranda, Alannah; Roberts, Benjamin Z; Holloway, Breanna M; Peek, Elizabeth; Rosberg, Holden; Ayoub, Samantha M; Piomelli, Daniele; Jung, Kwang-Mook; Barnes, Samuel A; Rossi, Steven; Geyer, Mark A; Perry, William; Minassian, Arpi; Young, Jared W. (2025). Chronic cannabis use in people with bipolar disorder is associated with comparable decision-making and functional outcome to healthy participants.. Translational psychiatry, 15(1), 506. https://doi.org/10.1038/s41398-025-03718-4

MLA

Miranda, Alannah, et al. "Chronic cannabis use in people with bipolar disorder is associated with comparable decision-making and functional outcome to healthy participants.." Translational psychiatry, 2025. https://doi.org/10.1038/s41398-025-03718-4

RethinkTHC

RethinkTHC Research Database. "Chronic cannabis use in people with bipolar disorder is asso..." RTHC-07147. Retrieved from https://rethinkthc.com/research/miranda-2025-chronic-cannabis-use-in

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.