Cannabis Use, Health Problems, and Criminal Offences All Rose in Germany from 2009 to 2021

Age-standardized cannabis use prevalence nearly doubled (5.7% to 10.6%), cannabis-related diagnoses more than tripled (1.1 to 3.7 per 1,000), and minor possession offences increased (1.8 to 3.1 per 1,000) between 2009 and 2021. The steepest increases in use and offences were among 40-59 year olds, while the largest diagnostic increases were in 35-44 year olds. Rates for minors remained relatively stable.

Researchers analyzed three national routine data sources: population-based surveys for cannabis use prevalence, ICD-10 F12 code outpatient medical data for cannabis-related diagnoses, and registered narcotics law violations for minor possession offences. Age-standardized rates were calculated across German federal states from 2009 to 2021.

Germany was preparing to decriminalize cannabis when this study was conducted, making the baseline data on use, health problems, and legal consequences critical for evaluating the impact of policy changes. The finding that health problems rose faster than use itself suggests that either cannabis potency or patterns of problematic use are intensifying.

Germany legalized recreational cannabis in 2024, making this pre-legalization data invaluable as a baseline. The pattern of health problems rising faster than use is consistent with trends seen in other countries and may reflect higher-potency products or shifts in consumption patterns.

Outpatient diagnostic data depends on clinical coding practices, which may have changed over time (increased awareness could inflate apparent increases). Survey-based prevalence may undercount true use. The study period ends before legalization, so it captures pre-reform trends only.