Treating cannabis use disorder: Exploring a treatment as needed model with 34-month follow-up

Research has demonstrated that motivational enhancement (MET) and cognitive behavioral therapy (CBT) are some of the most effective interventions for adults with cannabis use disorder (CUD). As few as two sessions of combined MET and CBT has produced abstinence and reductions in cannabis use greater than delayed treatment controls. Despite their efficacy, outcomes in previous studies yielded abstinence rates from cannabis in the range of 20-30% at follow-ups of 6 to 12 months, and CUD remained a chronic condition for many. Additional models of providing treatment "as needed" (PRN), rather than as a single fixed-dose, are necessary to meet the different needs of adults with CUD and reengage those who do not respond to treatment initially or who relapse later. In the current study, 87 adults who met DSM-IV criteria for cannabis dependence were randomly assigned to receive either a fixed-dose of nine sessions of MET/CBT or to a PRN condition that provided a smaller initial dose of treatment, but allowed repeated access to treatment for 28 months. Cannabis use and associated problems were assessed every six months throughout a 34-month period. More than one-third of participants in the PRN condition accessed additional treatment episodes, but the total number of treatment sessions that participants utilized was comparable across conditions. Both treatments yielded significant reductions in cannabis use and associated problems at each follow-up. Contrary to hypotheses, the PRN condition did not yield better outcomes at the longer-term follow-ups. The fixed-dose condition produced greater rates of abstinence at the first follow-up, but otherwise there were no between group differences in outcomes. Future studies should test active approaches to reengaging participants with treatment when initial outcomes are less than optimal.