Associations of adolescent alcohol use and self-reported alcohol tolerance with risk of self-harm and suicide in early adulthood: a birth-cohort study

Abstract

Objective We aimed to assess the predictive associations of age at first drink (AFD), age at first intoxication (AFI), frequency of intoxication, and self-reported alcohol tolerance at age 15-16 to self-harm requiring medical attention or suicide death by age 33.<p>

<p>Method In an ongoing follow-up study, the Northern Finland Birth Cohort 1986, a total of 7,735 individuals were included at age 15-16. Information on alcohol and other substance use was assessed via questionnaires. Information on self-harm or suicide was collected from national registers until the participants were 33 years of age. Baseline psychiatric symptomatology measured with the Youth Self-Report questionnaire and socio-demographic background variables were controlled for in multivariable analyses using Cox regression analyses.

<p>Results Male gender and psychiatric symptoms at age 15-16 were consistently associated with greater risk of self-harm and suicide death. When baseline psychiatric symptomatology and other background variables were adjusted for, younger AFI (Hazard Ratio, HR, 2.28. 95% CI 1.16-4.47) and high inherent alcohol tolerance (HR 3.76, 95% CI 1.55-9.08) were associated with self-harm. Furthermore, frequent alcohol intoxication (HR 5.39, 95% CI 1.44-20.23) and high inherent alcohol tolerance (HR 6.20, 95% CI 1.18-32.45) were associated with suicide death by age 33.

<p>Conclusions High alcohol tolerance, age of onset and frequency of alcohol intoxication in adolescence, appear to be significant predictors of self-harm and suicide in early adulthood. Self-reported alcohol tolerance in adolescence is a novel empirical approach to assess adolescent alcohol use associating with subsequent harms.