Adolescent Cannabis Use and Its Associations With Decision-Making and Episodic Memory: Preliminary Results From a Longitudinal Study

Objective: Impairments in neurocognitive functioning, including memory and executive functions, have been identified among adult cannabis users; however, less is known about the effects of cannabis use (CU) among adolescent users. Delineating the directionality of associations between CU and neurocognition has been restricted due to the relatively few longitudinal studies examining this question. As such, we examined whether decision-making prospectively predicted CU, and whether increases in CU were associated with changes in decision-making and episodic memory among a sample consisting predominantly of adolescent cannabis users. Method: Adolescents (n = 401), aged 14-17 at baseline, completed 3 (biannual) assessments across a 1-year period. Latent growth curve analyses in structural equation models were conducted to examine potential associations between decision-making and growth in CU, and associations between change in CU and change in decision-making or episodic memory performance. Results: Significant cross-sectional associations were observed between greater CU and poorer decision-making and episodic memory performance (p < .05), consistent with our hypotheses and prior findings. However, decision-making performance did not predict change in CU frequency across 1 year. Neither was change in decision-making associated with changes in CU. However, increasing cannabis use was associated with worsening immediate (but not delayed) episodic memory. Conclusions: Our findings suggest that poorer decision-making does not put teens at relatively early stages of cannabis use at risk for further escalation in use over one year. However, increasing cannabis use over the same period was associated with declines in immediate memory. General Scientific Summary The present findings suggest that cannabis use in adolescence adversely affects episodic memory but not decision-making. Therefore, our results do not support interventions focused on decision-making as a prevention effort for cannabis addiction.