Examining a structural model of the relationships among alcohol use, marijuana/hashish use, their effects, and emotional and psychological problems over time in a cohort of high‐risk youths

Using data collected in a longitudinal study of detained juveniles, we test a model of the relationships among alcohol and marijuana or hashish use, reported adverse effects of the use of these substances, and emotional and psychological problems. Significant interrelationships were found among these factors over time. Degree of involvement in alcohol and marijuana or hashish use (measured either by self‐reports or both self‐reports and urine test results) was significantly related at Time 1 with the number of reported averse effects of the use of each specific substance; a similar relationship was found at Time 2 for marijuana or hashish use. In addition, emotional and psychological problems were significantly associated with reported adverse effects of the use of alcohol or marijuana or hashish at each time period. The results further indicate that youths who become more involved in the use of alcohol or marijuana or hashish over time report more adverse effects of their use of each of these substances. These findings highlight a network of interconnected experiences that add insight into the youths’ functioning over time. At the same time, the youths’ Time 2 emotional and psychological problems, reported effects of their alcohol use, and reported effects of their marijuana or hashish use are weakly predicted by the variables in the model; these findings suggest considerable change in these experiences over time. Theoretical and policy implications of these findings are discussed.