Successful outcomes with low-threshold intervention for cannabis use disorders in Norway - an observational study.

Aims: Cannabis is the most commonly used regulated drug by European youths. Yet, few cannabis-specific interventions have been examined in Europe. The Cannabis Cessation Program (CCP) was developed in Sweden in the 1990s and has been implemented in some Norwegian municipalities. The present study aimed to examine outcomes of this intervention in the Norwegian setting.

Method: The respondents (N = 102) were recruited in four community-based CCPs in Norway. We examined their changes in cannabis use, other substance use, mental distress, well-being, sense of coherence (SoC), and social networks, from baseline (T0) to post-treatment (T1) and up to a 3-month follow-up period (T2). Changes were evaluated with pair-wise t-tests.

Result: Seventy-six participants (75%) completed the 8-week program, according to plan. All participants reported a significant reduction in cannabis use at T1 (average reduction ~16 days per month) and at T2 (N = 59; ~13 days per month). Among those that completed the program, 67% was abstinent from cannabis at T1 and 37% was abstinent at T2. An intention-to-treat analysis showed that 50% (51/102) and 22% (22/102) were abstinent from cannabis use at T1 and T2, respectively. In parallel to abstinence, we observed a substantial reduction in mental distress and an increase in well-being and SoC. Respondents socialized with fewer friends with current substance use, but drug-free social networks were not expanded.

Conclusion: Our findings suggested that the CCP was a valuable, low-threshold manual-based intervention for cannabis use disorders. It showed considerable potential for reducing individuals' cannabis use.

Clinical Trial Registration: Clinicaltrials.gov no. NCT04989205. Registered 12 July 2021, i.e., the study was retrospectively registered.