Adolescents' drinking habits predict later occurrence of traumatic brain injury: 35-year follow-up of the northern Finland 1966 birth cohort

Abstract Purpose To examine the relationship between adolescents' drinking habits and the risk of traumatic brain injury. Method We prospectively studied the 10,424 adolescents from northern Finland who were born during the year 1966 after exclusion of those who died or emigrated. Data on the frequencies of alcohol use and drunkenness after alcohol intake were collected at the age of 14 years, and the subjects were thereafter followed up until the age of 35 years. The traumatic brain injuries (TBI) that had occurred after the age of 14 years were recorded from the Finnish Hospital Discharge Register and the Registry for Causes of Death by Statistics Finland. Results Compared with never-drinkers, those who drank alcohol once a month or more often (frequent drinkers) or had sometimes been drunk before the age of 14 years had an increased crude relative risk of TBI during the follow-up time of 21 years (relative risk [RR] 2.04; 95% confidence interval [CI] 1.06–3.93 and RR 1.42; 95% CI 1.08–1.88 for frequent alcohol use and drunkenness, respectively). Adjusted (for fathers' occupation, family background, place of residence and school performance) RRs for TBI during the 21-year follow-up were 2.21 (1.14–4.29) and 1.35 (1.01–1.79), respectively. Conclusions The habit of frequent drinking and the feeling of having been drunk at the age of 14 years or before seem to increase the risk for TBI in adolescence and young adulthood. Increased efforts should be made by policy makers to restrict adolescents′ alcohol drinking.