UC Santa Cruz

Objective

To report results from a follow-up study of alcohol, cannabis and other drugs on suicidal behavior.

Method

We estimated prospective associations of substance use as a risk factor for incident suicide ideation and attempt, from a follow-up conducted in 2013 (n = 1071) of the original Mexican Adolescent Mental Health Survey conducted in 2005.

Results

Cannabis use before age 15 (ideation risk ratio (RR) = 3.97; 95% confidence interval (CI) = 1.43-11.03; attempt RR = 5.23; 95% CI = 1.17-23.32), early onset of DSM-IV drug use disorder (DUD) among cannabis users (ideation RR = 3.30; 95% CI = 1.11-9.84; attempt RR = 4.14; 95% CI = 1.28-13.36), high frequency of cannabis use (RR for attempts = 4.60; 1.03-20.60) and recent DSM-IV-DUD among cannabis users (RR for attempts = 4.74; 1.09-20.57) increased the RR. For "other drug use", significant results were found among those with high frequency use of other drugs such that they had a higher RR of suicide attempt (5.04; 1.03-24.64). For alcohol, only those who initiated alcohol before age 15 had higher RRs of suicide attempt (1.79; 1.00-3.20).

Discussion

Those who used cannabis at an early age, early onset of DSM-IV-DUD, and those with heavy cannabis use and recent DSM-IV-DUD among cannabis users in the last 12-months had increased risk of suicide ideation and attempt. Drugs other than cannabis showed some of these associations, but to a lesser degree. Prevention of substance use and treatment of those already engaged in drug use, by decreasing suicide ideation and attempt, may help to prevent suicide in Mexico.