Computerized Brief Intervention (CBI) for Cannabis

Evaluations

• Computer and therapist based brief interventions among cannabis-using adolescents presenting to primary care: One year outcomes.

  Walton MA, Bohnert K, Resko S, Barry KL, Chermack ST, Zucker RA, Zimmerman MA, Booth BM, Blow FC. Drug and Alcohol Dependence. 2013. 132(3): 646-643. PMCID: PMC3770780.

  Summary: In this randomized controlled trial examining the impact of a computerized brief intervention (CBI) for cannabis use, adolescents receiving care at seven federally qualifying health clinics were screened. Adolescents currently using cannabis were eligible for randomization. A total of 328 participants were randomly assigned to either a computerized brief intervention (CBI), a therapist-delivered brief intervention (TBI), or to a control condition. While participants assigned to CBI completed one computerized, brief, individual session, participants assigned to TBI met with a trained therapist for one brief, individual session. Participants assigned to the control group received an educational brochure on cannabis and cannabis-related problems. Cannabis use, cannabis-related consequences, and other substance use were measured at 3, 6, and 12 month follow-up assessments. Overall, cannabis use decreased among all participants over time. Significant decreases in cannabis use were found in the CBI and TBI groups, while participants in the control group had no significant changes in cannabis use. Comparisons of the CBI and control groups revealed that drug use and cannabis-related consequences decreased more in the CBI group than the control group at the 3 month follow-up. Compared to the control group, the TBI group had no significant decreases in cannabis use during the follow-up period. By 12 months, no significant differences were detected between the three groups.

  Take Away: CBI contributes to short-term decreases in cannabis use among adolescents already using cannabis. There was no difference in effects between the CBI and TBI approaches.

• A randomized controlled trial testing the efficacy of a brief cannabis universal prevention program among adolescents in primary care.

  Walton MA, Resko S, Barry KL, Chermack ST, Zucker RA, Zimmerman MA, Booth BM, Blow FC. Addiction. 2014. 109(5): 786-797. PMCID: PMC3984620.

  Summary: To examine the effects of a brief intervention on cannabis initiation, adolescents (age 12-18) at seven federally qualifying health clinics were screened for cannabis use. After completing the computerized screening questionnaire, 714 adolescents had not initiated cannabis use. These participants were randomly assigned to one of three treatments: a computerized brief intervention (CBI), a therapist-delivered brief intervention (TBI), or a control condition. Participants assigned to CBI completed one individual session at the health clinic. Participants assigned to TBI met with a trained therapist and completed one session of motivational interviewing. Control participants received a brochure describing signs of cannabis use problems and providing community resources. Follow-up interviews were conducted 3, 6, and 12 months after the intervention session. Overall, the CBI group was less likely to initiate cannabis use than the control group. During the 12 month follow-up period 24% of control participants used cannabis, while only 17% of CBI participants used cannabis. Compared to the control condition, the frequency of cannabis use was also lower in the CBI group, but only at 3 and 6 months post-intervention. No differences in cannabis use frequency were detected after 6 months. At all follow-ups, cannabis use was equivalent in participants assigned to the control condition and TBI.

  Take Away: The CBI intervention for cannabis was successful in reducing cannabis initiation and frequency of use. These changes were not sustained after 6 months. There was no difference in effects between the CBI and TBI approaches.