Towards explaining time trends in adolescents’ alcohol use: a multilevel analysis of Swedish data from 1988 to 2011

BACKGROUND: Alcohol use has decreased among Swedish adolescents in the past few decades. We examined peer and parent factors (i.e. time spent with peers, time spent with parents and parental monitoring) that could contribute to explaining this trend by investigating their main effects and interaction effects with investigation years on alcohol use. We furthermore examined whether municipality-level socioeconomic conditions could contribute to explaining the trend. METHODS: We used data from a repeated cross-sectional study that took place eight times between 1988 and 2011. The study targeted all ninth grade students (15–16 years old) in Värmland County, Sweden. Adolescents (N = 22 257) reported their monthly alcohol use, time spent with peers and parents and parental monitoring. Municipality-level socioeconomic conditions were based on parent education levels. RESULTS: Logistic multilevel regression analyses showed that peer and parent factors and municipality-level socioeconomic conditions were associated with alcohol use among adolescents. The interaction effects between peer and parent factors and investigation years were not significant. The decreased trend in time spent with peers was associated with the decreased trend in frequency of alcohol use over time. CONCLUSIONS: The findings of the current study provide an indication that the decreased trend in alcohol use that has been observed in Swedish adolescents over the past few decades may be related to changes in adolescents’ social interactions with peers.