Cannabis use before age 15 was linked to nearly 4x higher risk of suicidal thoughts and 5x higher risk of suicide attempts in young Mexicans

In a follow-up study of over 1,000 young Mexicans, early cannabis use (before age 15), heavy use, and cannabis use disorders all significantly predicted later suicidal thoughts and attempts.

Borges, Guilherme et al.·Journal of psychiatric research·2017·Moderate EvidenceProspective Cohort
RTHC-01339Prospective CohortModerate Evidence2017RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Prospective Cohort
Evidence
Moderate Evidence
Sample
N=1,071

What This Study Found

In a prospective study following 1,071 young Mexicans from 2005 to 2013, cannabis use before age 15 was associated with nearly 4 times the risk of suicidal ideation (RR=3.97) and over 5 times the risk of suicide attempt (RR=5.23).

Early-onset cannabis use disorder among cannabis users tripled the risk of ideation (RR=3.30) and quadrupled the risk of attempt (RR=4.14). High-frequency cannabis use was associated with 4.6 times the risk of attempt, and recent cannabis use disorder with 4.7 times the risk.

Other drugs showed some similar associations but generally to a lesser degree. For alcohol, only initiation before age 15 was linked to increased attempt risk (RR=1.79).

Key Numbers

Cannabis before age 15: ideation RR=3.97 (95% CI 1.43-11.03), attempt RR=5.23 (95% CI 1.17-23.32). Early-onset DUD: ideation RR=3.30, attempt RR=4.14. High-frequency use: attempt RR=4.60. Recent DUD: attempt RR=4.74. Alcohol before age 15: attempt RR=1.79.

How They Did This

Prospective follow-up of the original Mexican Adolescent Mental Health Survey conducted in 2005, with follow-up in 2013 (n=1,071). Researchers estimated risk ratios for incident suicidal ideation and attempt based on earlier substance use patterns, adjusting for confounders.

Why This Research Matters

Suicide is a leading cause of death among young people in Mexico and globally. This prospective design, following the same individuals over eight years, strengthens the evidence that early and heavy cannabis use precedes suicidal behavior rather than simply co-occurring with it. The specificity of cannabis effects beyond other substances is notable.

The Bigger Picture

The consistency of the cannabis-suicide association across early use, heavy use, and use disorders suggests a dose-response relationship. The Latin American context is important because cannabis policy and cultural attitudes differ from North America and Europe, yet the associations appear similar, suggesting biological rather than purely cultural pathways.

What This Study Doesn't Tell Us

Relatively small follow-up sample (1,071 participants). Wide confidence intervals on some estimates reflect limited statistical power. Observational design cannot confirm causation. Self-reported substance use and suicidal behavior may be subject to reporting bias. The study cannot fully account for shared risk factors.

Questions This Raises

  • ?What mechanisms link early cannabis use to later suicidal behavior?
  • ?Would prevention of early cannabis initiation reduce suicide rates among Mexican youth?
  • ?Do these associations differ across Latin American countries with varying cannabis policies?

Trust & Context

Key Stat:
Cannabis use before age 15: 4x suicidal ideation risk, 5x suicide attempt risk
Evidence Grade:
Prospective cohort study with 8-year follow-up. Strong temporal design but limited by small sample size and wide confidence intervals.
Study Age:
Published in 2017. The association between early cannabis use and suicidal behavior continues to be studied across different populations.
Original Title:
Alcohol, cannabis and other drugs and subsequent suicide ideation and attempt among young Mexicans.
Published In:
Journal of psychiatric research, 91, 74-82 (2017)
Database ID:
RTHC-01339

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-ControlFollows or compares groups over time
This study
Cross-Sectional / Observational
Case Report / Animal Study

Enrolls participants and follows them forward in time.

What do these levels mean? →

Frequently Asked Questions

Does cannabis cause suicidal thoughts?

This study found that early and heavy cannabis use preceded suicidal behavior in a prospective design, which is stronger evidence than cross-sectional studies. However, it cannot prove causation. The association could involve cannabis exacerbating underlying vulnerability, or shared risk factors not fully controlled for.

Why is age of first use important?

Starting cannabis before age 15 carried the highest risk ratios in this study. The adolescent brain is still developing, particularly in areas governing emotional regulation and impulse control. Early exposure may disrupt these developmental processes in ways that increase vulnerability to suicidal thinking.

Read More on RethinkTHC

Cite This Study

RTHC-01339·https://rethinkthc.com/research/RTHC-01339

APA

Borges, Guilherme; Benjet, Corina; Orozco, Ricardo; Medina-Mora, Maria-Elena; Menendez, David. (2017). Alcohol, cannabis and other drugs and subsequent suicide ideation and attempt among young Mexicans.. Journal of psychiatric research, 91, 74-82. https://doi.org/10.1016/j.jpsychires.2017.02.025

MLA

Borges, Guilherme, et al. "Alcohol, cannabis and other drugs and subsequent suicide ideation and attempt among young Mexicans.." Journal of psychiatric research, 2017. https://doi.org/10.1016/j.jpsychires.2017.02.025

RethinkTHC

RethinkTHC Research Database. "Alcohol, cannabis and other drugs and subsequent suicide ide..." RTHC-01339. Retrieved from https://rethinkthc.com/research/borges-2017-alcohol-cannabis-and-other

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.