Aim. To evaluate the effectiveness, safety, and cost-effectiveness of psychosocial interventions for cannabis use disorder (CUD). Design. A systematic review of randomized controlled trials (RCTs; PROSPERO protocol CRD42024553382). We searched databases (MEDLINE/PsycInfo/Cochrane CENTRAL) to 12-Jun-2024. We assessed results using Risk of Bias 2 and conducted meta-analyses where possible. Setting. Inpatient/outpatient/community-based. Participants. Individuals with CUD aged ≥16 years. Interventions. Psychosocial interventions lasting >4 sessions, delivered in real time. Measurements. Primary outcomes were continuous- and point-abstinence, withdrawal intensity, treatment completion and adverse events. Findings. We included 22 RCTs (3,304 participants). At the end of treatment, cognitive-behavioural therapy (CBT) increased point abstinence (odds ratio [OR]=18.27, 95% confidence interval [9.00; 37.07]), and continuous abstinence (OR=2.72 [1.20; 6.19]), but reduced treatment completion (OR=0.53 [0.35; 0.85]) versus inactive/nonspecific comparators. Dialectical behavioural/acceptance and commitment therapy increased point abstinence versus inactive/nonspecific comparators (OR=4.34 [1.74; 10.80]). The effect of CBT plus affect management versus CBT on point abstinence was OR=7.85 [0.38; 163.52]. The effect of CBT plus abstinence-based contingency management versus CBT on point abstinence was OR=3.78 [0.83; 17.25], and on continuous abstinence OR=1.81 [0.61; 5.41]. For CBT plus abstinence-contingency management versus CBT plus attendance-contingency management, the effect on point abstinence was OR=1.61 [0.72; 3.60], and on continuous abstinence OR=2.04 [0.75; 5.58]. The effect of community reinforcement on point abstinence was OR=0.29 [0.04; 1.90] versus CBT, and on continuous abstinence OR=47.36 [16.00; 140.21] versus nonspecific comparator. Interventions other than CBT may not affect treatment completion. No adverse events were reported. No study reported withdrawal intensity. Two economic evaluations reported higher costs for more complex psychosocial interventions and contingency management. Conclusions. Cognitive-behavioural and dialectical behavioural/acceptance and commitment therapies may increase abstinence relative to inactive/nonspecific comparators. The conclusions remain tentative due to low to very low certainty of evidence and small number of studies.

The authors have declared no competing interest.

This review was funded by the NIHR Evidence Synthesis Programme (NIHR167862). The views expressed are those of the authors and not necessarily those of the NIHR or the Department of Health and Social Care.

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The data to support the findings of this review are available in Table 3, Figures 2-5, and Supporting Information 8-13.