[Development of cannabis use from adolescence to young adulthood and risk and protective factors for problematic use-results of a longitudinal study].

Introduction: On April 1, 2024, the new cannabis law came into force, legalizing the use of cannabis in Germany. Even before, Cannabis had been one of the most commonly used drugs. However, problematic cannabis use is related to a variety of health risks especially for adolescents and young adults. This study examines the development of cannabis use from adolescence to young adulthood as well as risk and protective factors for problematic use among young adults.

Methods: The data come from the German longitudinal study "Future Family" (Start: 2001; 18-year follow-up: 2020-22). The sample includes N = 278 young adults (M = 22.3 years). Prevalence rates and the development of cannabis use from adolescence to young adulthood are analyzed. Various child- and family-related variables from early childhood and adolescence are examined as potential risk and protective factors for problematic cannabis use.

Results: The lifetime prevalence of cannabis use was 57.6%, and the prevalence of problematic use was 13.7%. Young men had a 3.3 times higher risk of problematic cannabis use compared to young women. Young adults who had already used cannabis at least once in their youth when surveyed had a 2.6 times higher risk of problematic use in young adulthood. The extent of mother-reported externalizing behavior problems in adolescence significantly predicted problematic use eight years later.

Discussion: The results confirm that cannabis use and problematic use in young adulthood were not a rare phenomenon even before legalization. They highlight the need for both conditional and behavioral preventive actions and provide numerous starting points for future research.