Cannabis-related treatment demand at the eve of German cannabis legalization - a 20-years trend analysis.

Post-2000, the prevalence of cannabis consumption has been rising internationally. This paper investigates whether cannabis-related treatment demand in German outpatient addiction care facilities (OACFs) has been following this trend. Treatment demand related to cannabis use disorder (CUD) for the period 2001 to 2021 was investigated using data from the nation-wide standardized German Addiction Care Statistical Service. Analyses covered all and first-time treatment admissions, demographics, and treatment outcomes. We identified years with significant changes in slope or direction of trends through joinpoint regression. Trends within the CUD client population were contrasted with trends among the entire OACF client population. CUD is the second-most common cause for OACF admissions in Germany. Between 2001 and 2021, the share of CUD-related cases among total OACF caseload increased from 7.1 to 19.9%, whereby the share of first-time treatment admissions declined from 79.6 to 55.6%. The share of CUD client population > 35 years almost tripled from 6.0 to 17.4%, that of female client population rose from 15.6 to 18.1%. From 2001 to 2007, the share of CUD-related treatments completed with improved symptomatology increased from 54.7 to 65.6%, followed by a marginal decline. CUD-related treatment demand is growing in Germany's OACFs, involving a client population that is increasingly older and more experienced with the addiction care system. As current intervention programmes mainly target adolescents and young adults who have been consuming cannabis only for a short time, adapting service offers to the changing client profiles appears paramount to improve treatment effectiveness.