Using an Optimized Marijuana Purchase Task to Examine Cannabis Demand in Relation to Cannabis Misuse in Heavy Drinking Emerging Adults.

OBJECTIVE: A behavioral economic approach to cannabis misuse emphasizes a crucial role of high drug demand (i.e., reinforcing value), which may be measured using a marijuana purchase task (MPT). The multiple indices from this measure have been associated with cannabis misuse, but somewhat inconsistently, possibly because of task variability across studies. Based on recent qualitative research, the current study implemented an optimized MPT to examine the underlying factor structure and the relationship between cannabis demand and both cannabis misuse and motivation to change. METHOD: Participants were two independent samples of emerging adults who reported cannabis use and heavy episodic drinking in the last month, one Canadian (n = 396) and the other American (n = 275). Both were assessed using an MPT, the Cannabis Use Disorder Identification Test (CUDIT), the Marijuana Adverse Consequences Questionnaire (MACQ), and readiness to change items. RESULTS: Principal component analyses of the MPT indices revealed the same two-factor latent structure in both samples, interpreted as Amplitude (intensity, O_max, elasticity) and Persistence (breakpoint, P_max). Regressions revealed that Amplitude was significantly associated with CUDIT and MACQ in both samples. In the Canadian sample, Persistence was also significantly associated with CUDIT and MACQ, and both factors were associated with motivation to change. CONCLUSIONS: The optimized MPT generated a two-factor latent structure that was parallel across samples, and the Amplitude factor was consistently associated with cannabis misuse. The current findings indicate the robust relevance of behavioral economic demand for cannabis in relation to cannabis misuse but suggest that links to motivation may be sample-specific.