Multiple motives for cannabis use: identifying common motive combinations and exploring differences across combinations.

BACKGROUND: Several ecological momentary assessment studies have examined event-level associations between motives for cannabis use and cannabis use outcomes (e.g., duration of intoxication, consequences), and endorsing multiple motives during the same observation has been linked to heavier cannabis use and more consequences. However, it remains unclear whether specific combinations of motives are differentially associated with cannabis use outcomes above and beyond the effect of endorsing more motives. METHODS: We utilized ecological momentary assessment data from 571 young adult females who regularly used cannabis to conduct a multilevel latent class analysis of observations during which multiple motives for cannabis use were endorsed and compared results to those derived from a count of the number of motives endorsed. RESULTS: Endorsing more motives (operationalized as a count of motives) was associated with heavier cannabis use and more consequences of use at the event-level. Six common combinations of motives (i.e., classes) were identified in the latent class analysis of observations with multiple motives. Results indicated differences among motive classes with the same number of motives. For example, the two classes characterized by the endorsement of three motives displayed different patterns with one (coping, social, enhancement) being consistently associated with heavier use than most classes characterized by endorsing two motives, while the other (coping, enhancement, medical) was not consistently associated with heavier use. Further, one class characterized by endorsement of two motives (coping and medical) was consistently associated with lighter use and fewer consequences compared to other classes characterized by endorsement of two motives. CONCLUSION: Results indicate that specific combinations of motives are associated with differences in cannabis use outcomes above and beyond the effect of simply endorsing more motives.