Objective
To conduct a pilot RCT investigating the feasibility, acceptability, and preliminary efficacy of dialectical behavioral therapy (DBT) for marijuana cessation and craving reduction.

Methods
Sixty-one patients with marijuana use disorder diagnoses were randomly assigned to a DBT group or a control group (psycho-education). Patients completed measures at pre-intervention, post-intervention, and at two-month follow-up. The Marijuana Craving Questionnaire (MCQ) and marijuana urine test kits were used to assess craving and abstinence respectively.

Results
The feasibility of DBT was significantly higher than control group feasibility. In the DBT 29/30 participants completed all sessions (96% retention) and 24/31 control group participants completed all sessions (77% retention) (χ2 = 4.95, p = 0.02). Moreover, 29/30 (96%) participants in the DBT group completed the two-month follow-up and 20/31 (64.5%) control group members completed the two-month follow-up (χ2 = 9.97, p = 0.002). The results showed that patients in the DBT group had significantly higher intervention acceptability rates (16.57 vs. 9.6) than those in the control group. This pattern was repeated for appropriateness rates (p < 0.05). The overall results for craving showed that there was no significant difference between the groups (F = 3.52, p > 0.05), although DBT showed a significant reduction in the “emotionality” subscale compared to the control group (F = 19.94, p < 0.05). To analyze cessation rates, DBT was compared to the control group at the posttest (46% vs. 16%) and follow-up (40% vs. 9.5%) and the results confirmed higher effectiveness in the DBT group for cessation (p < 0.05). Furthermore, among those who had lapsed, participants in the DBT group had fewer consumption days than those in the control group (p < 0.05).

Conclusions
DBT showed feasibility, acceptability, and promising efficacy in terms of the marijuana cessation rate.

Clinical trial registration
Thailand Registry of Clinical Trials, TCTR20200319007.