Aims: To assess the associations of intoxication frequency and number of drinks needed to become intoxicated in mid-adolescence with onset of psychiatric disorders in early adulthood.
Design, setting and participants: Prospective cohort study in Northern Finland, with people from the Northern Finland Birth Cohort 1986 who self-reported adolescent alcohol use: 6548 subjects (69.4% of the original sample). Data on alcohol use were collected using questionnaires at ages 15-16 years.
Measurements: Outcomes were any non-organic psychosis, mood disorder, anxiety disorder, any substance use disorder (SUD) and all the studied psychiatric disorders in early adulthood gathered from nation-wide health care, pension and insurance registers. Number of drinks needed to become intoxicated was categorized into three classes: (1) no alcohol use or intoxication, and (2) low and (3) high alcohol tolerance (more than seven/nine drinks for females/males) groups. Similarly, intoxication frequency was divided into three classes: (1) never, (2) one to two times and (3) three or more times during the past 30 days. Information regarding gender, family type, other drug use, psychopathology using Youth Self-Report (YSR) total score and parental psychiatric disorders were used as covariates.
Findings: In the multivariable analyses, both low [odds ratio (OR) = 3.0, 95% confidence interval (CI) = 1.3-6.7, P-value = 0.009] and high (OR = 4.4, 95% CI = 1.8-11.1, P-value = 0.001) alcohol tolerance were associated with increased risk of SUD. More frequent intoxication was associated with increased frequency of SUD (OR = 3.9, 95% CI = 2.0-7.3, P-value < 0.001) and mood disorder (OR = 1.6, 95% CI = 1.1-2.3, P-value = 0.008). The latter was attenuated after adjusting with concurrent psychopathology (YSR) and other drug use.
Conclusions: Both higher alcohol tolerance and frequent intoxication in adolescence appear to be associated with increased risk of future substance use disorder.
Keywords: Adolescent; alcohol tolerance; birth cohort; early adulthood; intoxication frequency; prospective; psychiatric disorders; substance use disorder.
© 2019 Society for the Study of Addiction.