Cannabis is the most frequently used illegal substance in Switzerland. Around 30% of the Swiss population aged 15 years and older consumed cannabis at least once and 3% report having used cannabis during the past month (Suchtmontoring 2012: Gmel et al. 2013). More men than women consume cannabis and the highest prevalence of cannabis use is found in the age group 20-34 years (Suchtmonitoring 2012). Most cannabis users in Switzerland smoke cannabis mixed with tobacco in the form of joints (Baggio et al. 2013). Possible consequences of regular cannabis use include respiratory diseases (such as chronic coughing) as well as memory and attention problems, which usually diminish when cannabis use is discontinued. Furthermore, cannabis use can increase the risk of psychotic symptoms and disorders and can cause physical and psychological dependence, with between 9 and 16% of all cannabis users developing cannabis dependence (Hall & Degenhardt 2009). Compared to substances such as tobacco and alcohol, cannabis contributes significantly less to the burden of disease in society (Degenhardt et al. 2013), whereby young people in particular underestimate the risk of developing a tobacco addiction by smoking cannabis together with tobacco, which in turn counts much more heavily for the burden of disease in society (see tobacco).
The ISGF is currently developing and investigating ways in which young and adult cannabis users can stop their cannabis consumption or control it better with the help of internet-based interventions or new family and group therapy methods. In addition, the ISGF collects consumption data on cannabis within the framework of the Swiss Addiction Monitoring and evaluation of Safer Nightlife Swiss.