Cannabis and mental health in Germany: a baseline estimation pre legalization

Background

Existing research suggests a connection between cannabis use and anxiety, depression, and bipolar disorders. With cannabis legalization planned in Germany for 2024, it's crucial to examine the extent of this association within the German population, to sufficiently support prevention and treatment services. In particular, we will focus on the extent to which past-year cannabis use in Germany is associated with the occurrence of various mental disorders, including anxiety, depression, and mania, and at how this prevalence has changed over time. 

Methods

The data encompass three waves (2015 [n = 9,204], 2018 [n = 9,267], 2021 [n = 9,046]; ntotal = 27,517) of the German Epidemiological Survey of Substance Abuse (ESA), a nationally representative study surveying individuals aged 18–64 in Germany. The presence of core symptoms of various mental health disorders was evaluated using questions adapted from the DIA-X-Stamm-Screening Questionnaire (DIA-X-SSQ), which was derived from the Composite International Diagnostic Interview (CIDI) developed by the World Health Organization. In particular, the ESA queries core symptoms of somatoform disorders, panic disorders, generalized anxiety disorder, social phobia, agoraphobia, specific phobias, depression (dysthymia), mania, and post-traumatic stress disorder, as well as affective disorders and anxiety disorders. Logistic regression was used to determine the likelihood of mental illnesses based on cannabis use within the last 12 months and sample weights were applied to address variations in region, age, sex, and education, ensuring the study's representativeness. 

Results

Age, gender, age of first use, frequency of use, and the presence of cannabis use disorder, recognized as influencing factors, were considered in the analysis. Preliminary findings reveal an association between core symptoms of several mental disorders and individuals who used cannabis in the past 12 months. The strength and direction of these associations varied based on the specific mental disorder. Additionally, the odds of exhibiting core symptoms increased for all disorders from 2015 to 2018 and 2021.

Discussion

The observed associations between past 12-month cannabis use and core symptoms of various mental disorders underscore the complexity of the relationship between cannabis consumption and mental health outcomes. The differing strengths of these associations across the three survey waves suggest a dynamic nature of this relationship that may be influenced by evolving societal attitudes, policies, and individual factors. It is essential to acknowledge the limitations of this study, including the reliance on self-reported data and the cross-sectional nature of the analysis. Understanding the nuanced associations between cannabis use and specific mental disorders can inform targeted public health interventions and prevention strategies.