Purpose: To study the association between adolescent alcohol use, smoking, other substance use, and later substance-use-related problems in a large general population sample in Northern Finland.
Methods: Data from the Northern Finland 1966 Birth Cohort (n = 11,017) were linked with National Crime Registers and the Finnish Hospital Discharge Register. Information on adolescent alcohol use, smoking, and other substance use was gathered via a questionnaire in 1980 and 1981, when subjects' age was 14 years. Logistic regression analyses were performed to examine the association between alcohol use frequency, tendency for heavy drunkenness, smoking and other substance use in adolescence, and drunk driving offenses between ages 15 and 32 years and hospital-treated substance use disorders between ages 16 and 31 years, adjusting for parental social class, family type, and school performance.
Results: The most powerful predictor for drunk driving was regular smoking at the age of 14 years (AOR 6.8, 95% CI 4.6-10.1 for males and 6.3, 95% CI 1.9-20.6 for females). Hospital-treated substance use disorders were associated with male regular smoking (AOR 9.4, 95% CI 4.6-19.2) and female regular alcohol use (AOR 7.5, 95% CI 2.6-21.5), and having often been heavily drunk (AOR 12.7, 95% CI 4.0-40.4) at the age of 14 years.
Conclusions: Teenage regular and heavy alcohol use and smoking are important predictors for substance-use-related problems later in adolescence and in young adulthood. Adolescents with early onset regular smoking and with drunkenness-oriented alcohol use are especially at risk for developing hazardous substance use later in life.