Contingency management for alcohol use disorder reduces cannabis use among American Indian and Alaska Native adults.
Determine whether a culturally tailored contingency management (CM) intervention targeting alcohol abstinence resulted in secondary effects on cannabis use among American Indian and Alaska Native (AIAN) adults. The research team conducted this secondary data analysis to examine cannabis abstinence using data from a randomized control trial of CM for alcohol use among three AIAN-serving organizations. One hundred and fifty-eight adults met the randomization criteria (i.e., submission of 50% or more urine samples and one alcohol-positive urine test during a 4-week, pre-randomization, observation period). For 12 weeks after randomization, participants received incentives for submitting a urine test negative for ethyl glucuronide (EtG < 150 ngmL, CM group) or incentives for submitting a urine sample regardless of abstinence (Non-contingent NC Control group). Generalized linear mixed effects models assessed group differences in cannabis abstinence during the intervention, verified by urine tetrahydrocannabinol negative tests (11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid <50 ngmL). At baseline, 42.2% (n 35) of participants in the NC group and 40.0% (n 30) of those in the CM group had a cannabis positive urine test. An overall intervention by time interaction was detected for a cannabis negative urine test (χ CM addressing alcohol misuse may be an effective strategy for decreasing cannabis use among AIAN adults. ClinicalTrials.gov number, Identifier NCT02174315.