Digital interventions to reduce cannabis use

Digital prevention and treatment interventions were found in a systematic review with meta-analysis (Boumparis et al., 2019, 30 studies, N=13 333) to have a small but significant effect in:

• reducing Cannabis use at post-treatment in the prevention interventions (6 studies, N=2564, g=0.33; 95% CI 0.13 to 0.54, p= 0.001) and in the treatment interventions (17 comparisons, N=3813, g=0.12; 95% CI 0.02 to 0.22, p= 0.02) as compared with controls;
• the effects of prevention interventions were maintained at follow-ups of up to 12 months (5 comparisons, N=2445, g=0.22; 95% CI 0.12 to 0.33,p < 0.001) but were no longer statistically significant for treatment interventions

Computerized interventions were confirmed to be effective, by an additional systematic review with meta-analysis (Olmos et al 2017, 9 RCTS; n=2963) in:

• reducing cannabis use (self-reported or urine testing) at 6 months follow-up (SMD: -0.19; 85% CI: -0.26 to -0.11; ).

Computerized interventions included personalised online feedback, motivational interviewing, computer-delivered cognitive behavioural therapy and clinician-assisted computer-based interventions.

Digital interventions (internet- or computer-based interventions) were found in a systematic review with meta-analysis (Hoch et al., 2016, 4 studies, N=1 928) to be effective in:

• reducing cannabis use (self-reported) after 3 month follow-up (MD – 4.07, 95 % CI -5.8 to -2.34). The largest treatment effects were found for the web-based online chat with a trained psychotherapist, plus online diary with weekly personalized, written feedback based on CBT/MI.