To test longitudinal additive and synergistic dual-process models in youth at documented risk for drug use. The specific dual-process approach examined suggests that engaging in drug use behaviors results from a dynamic interplay between automatically activated associative memory processes and executive reflective/control processes.Design
This 3-year, three-wave population-based prospective study used mobile computer-based assessments.Setting
Self-directed computer assessments were completed in school settings in the Los Angeles metropolitan area, California, USA.Participants
Seven hundred and twenty-five at-risk adolescents (44% female) in continuation high schools were recruited during 9th grade (age at recruitment, 14–16).Measurements
Key outcome measures included past year alcohol, marijuana and cigarette use at each assessment. Predictors included working memory capacity (WMC), associative memory, the interaction term WMC by associative memory, sex, age, ethnicity and acculturation.Findings
A significant cross-sectional interaction revealed tobacco-relevant associations were weaker predictors of cigarette use among males with higher WMC than among those with lower WMC (P < 0.004). Alternatively, drug-relevant associations were stronger predictors of past year alcohol (P < 0.001) and marijuana use (P = 0.02) among females with higher WMC than among those with lower WMC. Longitudinal analyses revealed no significant interactions after adjusting for predictive effects of previous drug use. With respect to WMC, females with higher WMC were less likely to use marijuana at 2-year follow-up (P = 0.03). First-order effects of drug-related associations predicted greater alcohol and marijuana use prospectively in males at 1- and 2-year follow up (P ≤ 0.03), and greater past year alcohol and marijuana use in females at 1-year follow up (P ≤ 0.03).Conclusions
Drug-relevant memory associations play a key role in drug use behavior in at-risk youth.