Our results suggest that, in the states assessed here, MMLs have not measurably affected adolescent marijuana use in the first few years after their enactment. Longer-term results, after MMLs are more fully implemented, might be different.

Developmental models highlight the impact of early risk factors on both the onset and growth of substance use, yet few studies have systematically examined the indirect effects of risk factors across several domains, and at multiple developmental time points, on trajectories of substance use and adult adjustment outcomes (e.g., educational attainment, mental health problems, criminal behavior). The current study used data from a community epidemiologically defined sample of 678 urban, primarily African American youth, followed from first grade through young adulthood (age 21) to test a developmental cascade model of substance use and young adult adjustment outcomes. Drawing upon transactional developmental theories and using growth mixture modeling procedures, we found evidence for a developmental progression from behavioral risk to adjustment problems in the peer context, culminating in a high-risk trajectory of alcohol, cigarette, and marijuana use during adolescence. Substance use trajectory membership was associated with adjustment in adulthood. These findings highlight the developmental significance of early individual and interpersonal risk factors on subsequent risk for substance use and, in turn, young adult adjustment outcomes.

This study tests a model of reciprocal influences between absenteeism and youth psychopathology using three longitudinal datasets (Ns= 20745, 2311, and 671). Participants in 1st through 12th grades were interviewed annually or bi-annually. Measures of psychopathology include self-, parent-, and teacher-report questionnaires. Structural cross-lagged regression models were tested. In a nationally representative dataset (Add Health), middle school students with relatively greater absenteeism at study year 1 tended towards increased depression and conduct problems in study year 2, over and above the effects of autoregressive associations and demographic covariates. The opposite direction of effects was found for both middle and high school students. Analyses with two regionally representative datasets were also partially supportive. Longitudinal links were more evident in adolescence than in childhood.

This study evaluated bidirectional associations between substance use, aggression, and delinquency across sixth, seventh, and eighth grades using data available from a large study of urban minority youth (n = 2,931). Group-based trajectory analysis revealed trajectories of aggression, delinquency, and substance use which support the existence of both adolescent-limited and life-course persistent offenders. In addition, a pattern of decreasing aggression was observed during middle school. Clear temporal associations were observed between developmental changes in aggression, delinquency, and substance use. Notably, the decreasing aggression trajectory was as likely to be associated with high trajectories of substance initiation as was the high aggression trajectory. Furthermore, trajectories of delinquency were differentially associated with future substance use; however, substance use trajectories did not predict trajectories of delinquency. There were few gender differences in the developmental progression of these problem behaviors during middle school with only two exceptions, males were more likely to follow a trajectory of decreasing aggression and a trajectory of high stable delinquency. Evaluations of ethnic/racial differences in the trajectory group membership also revealed few differences. The results of this study provide important information regarding interconnections between developmental changes in problem behavior that occur during the middle school years, highlighting groups that may be missed via traditional analytic approaches that predict mean changes.