AIMS

To examine whether the association between prevalence measures of suicidality and substance abuse/dependence among adolescents (1) is attenuated when temporal priority of exposure and outcome are taken into account, (2) extends to substance use (i.e. without disorder), (3) applies to tobacco use and dependence independent of illicit drugs and alcohol use/disorder, and (4) is confounded by comorbid mental illness.

DESIGN

Discrete-time survival models were applied to retrospectively reported age of onset of first suicidal ideation, plan and attempt and age of onset of first substance use and disorder.

PARTICIPANTS

3005 adolescents aged 12-17 residing in the Mexico City Metropolitan Area in 2005.

MEASUREMENTS

The World Mental Health computer-assisted adolescent version of the Composite International Diagnostic Interview was used to assess suicidal outcomes and psychiatric disorders including substance dependence/abuse.

FINDINGS

Use of and dependence on tobacco is as strong a predictor of subsequent suicidality as is use of and dependence with abuse of alcohol and drugs. The association between substance use and subsequent suicidality is not fully accounted for by comorbid mental illness.

CONCLUSION

Efforts to reduce the use as well as the abuse of alcohol, drugs and tobacco may help reduce the risk of subsequent suicidal behaviors among adolescents in Mexico.