Cannabis Use in Germany Increased Dramatically Across Both Time Periods and Birth Cohorts

Period effects showed cannabis use odds rising from OR 0.33 in 1995 to OR 2.96 in 2021. Cohort effects were even more dramatic, rising from OR 0.02 for those born in 1936 to OR 16.69 for those born in 2002. Age effects showed steep decline from OR 9.44 at age 18 to OR 0.13 at age 59.

Binary logistic regression using generalized additive models analyzed data from 10 waves (1995-2021) of the German Epidemiological Survey of Substance Abuse (ESA), a nationally representative household survey. N=78,678 adults aged 18-59. Age, period, and cohort effects estimated simultaneously.

Germany partially legalized recreational cannabis in 2024. This comprehensive pre-legalization baseline shows cannabis use was already rising dramatically through both secular trends and generational shifts, providing essential context for evaluating legalization's impact.

The steep age-related decline in use suggests most people who try cannabis do not continue long-term. But the massive cohort effect (800-fold difference between 1936 and 2002 birth cohorts) means each successive generation is starting from a higher baseline, which could eventually shift the age-prevalence curve upward.

Self-reported data subject to social desirability bias. Survey methodology changes over 26 years may affect comparability. Age-period-cohort models have inherent identification problems. German context may not generalize. Household surveys may miss heavy users and institutionalized populations.