Abstract
BACKGROUND: Two scientific and clinical challenges for treating cannabis use disorder (CUD) are developing efficacious treatments with high likelihood of uptake and scalability, and testing the clinical mechanisms by which treatments work. Because young adults experience more CUD than other age groups, a need exists to test the efficacy and hypothesized causal pathways of novel treatments for CUD. Text-delivered treatments have the potential to reach young adults by increasing access and perceived privacy. METHODS: We conducted a randomized clinical trial (n = 1078) of a 4-week CUD treatment with U.S. young adults from Colorado and Tennessee. Participants were allocated to Peer Network Counseling-text (PNC-txt), a text-message delivered brief motivational interviewing informed treatment, or a wait-list control condition, and followed for 6 months. RESULTS: No significant direct treatment effects on cannabis use were found between experimental conditions. However, significant treatment effects were identified on hypothesized mediators: readiness to change and protective behavioral strategies. Tests of indirect effects using latent change score mediation modeling showed the treatment group (PNC-txt) increased in readiness to change and protective behavioral strategies at the 1-month follow-up period, which led to decreases in the number of days participants used cannabis from baseline to 6-months, compared to controls. CONCLUSIONS: While no direct treatment effects were identified, PNC-txt appears successful in reducing cannabis use relative to controls indirectly by activating participants' motivation to change and through teaching harm reduction strategies. Results suggest targeting readiness to change and protective behavioral strategies as modifiable clinical mechanisms when treating CUD in young adults.