rethinkTHC Search
Menu
Study breakdown

An Umbrella Review of 25 Systematic Reviews Found Consistent Evidence Linking Cannabis to Suicidal Ideation and Attempts

Umbrella ReviewStrong evidence
The takeaway

Across 25 systematic reviews, evidence generally showed a positive association between recreational cannabis use and suicidal ideation and attempts, with younger initiation, longer use, and heavier consumption linked to worse outcomes, while therapeutic CBD was considered safe.

Psychiatrists, suicide prevention researchers, public health communicators, cannabis policy makers.

22 of 25 systematic reviews found positive association between cannabis and suicidality

What the researchers found

25 systematic reviews were included (24 on recreational use, 1 on therapeutic). Only 3 recreational use reviews found no effect or inconsistent results. Evidence showed positive associations between cannabis and suicidal ideation and attempts across general population, military veterans, and patients with bipolar or major depression. Younger initiation, long-term use, and heavy consumption were associated with worse outcomes. A bidirectional causal association was mentioned. Therapeutic CBD was considered safe.

Why it matters

This is the highest level of evidence synthesis available on cannabis and suicide risk. The consistency across 25 reviews, with only 3 finding null or inconsistent results, represents a strong signal that should inform both clinical practice and public health messaging.

The numbers in context

25 systematic reviews included. 24 on recreational use. 3 found no effect or inconsistent results. Associations found in general population, veterans, and bipolar/depression patients. Dose-response pattern with initiation age, duration, and amount.

How the study worked

Umbrella review searching 7 databases and 2 registries without restrictions. AMSTAR-2 for quality assessment. Corrected covered area and citation matrix for overlap assessment.

What this study cannot tell us

Umbrella review is limited by the quality of included reviews. AMSTAR-2 scores varied. Cannot determine causation from observational evidence alone. Overlap between included reviews may inflate apparent consistency. Publication bias possible.

How to read the evidence

Umbrella review (highest level of evidence synthesis) of 25 systematic reviews. Consistent findings across most reviews.

When this study was published

Published in 2023.

The bigger picture

Cannabis is the most common illicit substance found in suicide victims' toxicology tests. This umbrella review consolidates the evidence suggesting this is not coincidental. The distinction between recreational and therapeutic use (CBD appears safe) is clinically important.

Questions still open

  • Does cannabis directly increase suicide risk or is the association mediated by depression and other mental health factors?
  • Should suicide risk screening be standard for patients reporting heavy cannabis use?

Common questions

Is cannabis linked to suicide risk?
Across 25 systematic reviews, evidence consistently showed recreational cannabis use was associated with suicidal ideation and attempts, with stronger associations for earlier initiation, longer use, and heavier consumption.
Is CBD safe regarding suicide risk?
The one review on therapeutic cannabis found that CBD was considered safe. The suicide risk association appears specific to recreational cannabis use.

Read the original research

Suicidality risk after using cannabis and cannabinoids: An umbrella review.

Dialogues in clinical neuroscience, 25(1), 50-63

Citation

Shamabadi, Ahmad; Ahmadzade, Ali; Pirahesh, Kasra; Hasanzadeh, Alireza; Asadigandomani, Hassan. (2023). Suicidality risk after using cannabis and cannabinoids: An umbrella review.. Dialogues in clinical neuroscience, 25(1), 50-63. https://doi.org/10.1080/19585969.2023.2231466

Explore the wider topic