Sarah D. Lynne-Landsman

Effects of State Medical Marijuana Laws on Adolescent Marijuana Use

OBJECTIVES Medical marijuana laws (MMLs) have been suggested as a possible cause of increases in marijuana use among adolescents in the United States. We evaluated the effects of MMLs on adolescent marijuana use from 2003 through 2011. METHODS We used data from the Youth Risk Behavior Survey and a difference-in-differences design to evaluate the effects of passage of state MMLs on adolescent marijuana use. The states examined (Montana, Rhode Island, Michigan, and Delaware) had passed MMLs at different times over a period of 8 years, ensuring that contemporaneous history was not a design confound. RESULTS In 40 planned comparisons of adolescents exposed and not exposed to MMLs across states and over time, only 2 significant effects were found, an outcome expected according to chance alone. Further examination of the (nonsignificant) estimates revealed no discernible pattern suggesting an effect on either self-reported prevalence or frequency of marijuana use. CONCLUSIONS 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.

Testing a developmental cascade model of adolescent substance use trajectories and young adult adjustment

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.

Trajectories of aggression, delinquency, and substance use across middle school among urban, minority adolescents.

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.

School Attendance Problems and Youth Psychopathology: Structural Cross-Lagged Regression Models in Three Longitudinal Data Sets

This study tests a model of reciprocal influences between absenteeism and youth psychopathology using 3 longitudinal datasets (Ns = 20,745, 2,311, and 671). Participants in 1st through 12th grades were interviewed annually or biannually. Measures of psychopathology include self-, parent-, and teacher-report questionnaires. Structural cross-lagged regression models were tested. In a nationally representative data set (Add Health), middle school students with relatively greater absenteeism at Study Year 1 tended toward 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 2 regionally representative data sets were also partially supportive. Longitudinal links were more evident in adolescence than in childhood.

Do Trajectories of Household Risk in Childhood Moderate Pubertal Timing Effects on Substance Initiation in Middle School

Previous research on pubertal timing has either evaluated contextual predictors of early puberty or negative adjustment outcomes associated with off-time development, especially early maturation. In this study, we integrated these 2 lines of research by evaluating the moderating influence of early childhood household risk on associations between early puberty and 8th-grade substance use in a longitudinal sample of 1,070 participants. We determined trajectories of early childhood household risk using group-based trajectory analysis. Rates of early maturation were higher but not significantly so in groups with high household risk. Early timing was associated with higher rates of substance initiation only among individuals with a history of high household risk.

Is Sensation Seeking a Stable Trait or Does It Change over Time

The theory of sensation seeking has conceptualized this construct as a stable personality trait associated with a variety of problem behaviors. Reckless behavior theory posits that increases in reckless behavior during adolescence can be attributed, in part, to increases in sensation seeking. This study evaluated patterns of stability and change in sensation seeking among 868 urban, minority youth (53% female), followed longitudinally across middle school (6th–8th grades). Group-based trajectory analysis identified a stable low group (20%), a moderate increasing group (60%), and a stable high group (20%) each of which demonstrated unique associations with changes in problem behaviors. Stable low sensation seekers reported consistently low levels of aggression, delinquency, and substance use across middle school. Moderate increasing sensation seekers reported significant increases in these risk behaviors over time from levels near zero in the 6th grade. Stable high sensation seekers reported high, stable levels of aggression and delinquency upon entry into middle school as well as significant increases in substance use across middle school. These results lend support to both theories and highlight a need for caution when categorizing adolescents as high or low sensation seekers.

Prevention Trial in the Cherokee Nation: Design of a Randomized Community Trial

Despite advances in prevention science and practice in recent decades, the U.S. continues to struggle with significant alcohol-related risks and consequences among youth, especially among vulnerable rural and Native American youth. The Prevention Trial in the Cherokee Nation is a partnership between prevention scientists and Cherokee Nation Behavioral Health to create, implement, and evaluate a new, integrated community-level intervention designed to prevent underage drinking and associated negative consequences among Native American and other youth living in rural high-risk underserved communities. The intervention builds directly on results of multiple previous trials of two conceptually distinct approaches. The first is an updated version of CMCA, an established community environmental change intervention, and the second is CONNECT, our newly developed population-wide intervention based on screening, brief intervention, and referral to treatment (SBIRT) research. CMCA direct-action community organizing is used to engage local citizens to address community norms and practices related to alcohol use and commercial and social access to alcohol among adolescents. The new CONNECT intervention expands traditional SBIRT to be implemented universally within schools. Six key research design elements optimize causal inference and experimental evaluation of intervention effects, including a controlled interrupted time-series design, purposive selection of towns, random assignment to study condition, nested cohorts as well as repeated cross-sectional observations, a factorial design crossing two conceptually distinct interventions, and multiple comparison groups. The purpose of this paper is to describe the strong partnership between prevention scientists and behavioral health leaders within the Cherokee Nation, and the intervention and research design of this new community trial.

The Evaluation of Two First-Grade Preventive Interventions on Childhood Aggression and Adolescent Marijuana Use: A Latent Transition Longitudinal Mixture Model

Aggressive, disruptive behavior during early childhood has been linked to a number of later negative outcomes, one of them being adolescent marijuana use. This study evaluates the impact of two first-grade universal interventions (classroom-centered and family–school partnership) on the development of aggression in early childhood (grades 1–3) and marijuana use in adolescence (grades 8–12) via a latent transition longitudinal mixture model. For males, despite the significant proximal impact of the classroom-centered intervention on trajectory class membership of early childhood aggression, as well as the significant association between aggression trajectory class membership and marijuana use longitudinal latent class membership, the predicted probabilities of being in the high frequency marijuana use class did not differ significantly by intervention status, though in the expected direction. Associations for females are limited to the proximal impact of the classroom-centered intervention on trajectory class membership of aggression. This study extends the prior work of Petras et al. (Prev Sci 12:300–313, 2011) by considering that aggressive, disruptive behavior during early childhood is linked not only to adolescent aggressive, disruptive behavior (i.e., homotypic continuity) but also to adolescent marijuana use (i.e., heterotypic continuity) and by considering that an early intervention may influence later non-targeted behaviors through these heterotypic developmental pathways. Implications for developmental theories and substance abuse prevention are discussed.

Evaluating a pregnancy and STI prevention programme in rural, at-risk, middle school girls in the USA:

Objective: Young people in urban areas are often the focus of pregnancy and sexually transmitted infection (STI) prevention programmes because of their high risk of unwanted pregnancy and contracting an STI. Young people in rural areas are far less studied but also have a high risk of similar outcomes. This study evaluates Giving Our Girls Inspiration & Resources for Lasting Self-Esteem (GO GIRLS), an after-school pregnancy and STI prevention programme, in a sample of high-risk middle school girls living in rural areas using quasi-experimental methods. Design: GO GIRLS was assessed using the same survey administered at three time points: prior to the start of the programme, directly following completion of the programme and at the end of the school year. The sample for this study was drawn from a larger evaluation of a multi-faceted health initiative conducted over the course of the school year in three rural counties in South Central Florida. Setting: The GO GIRLS programme was implemented in a rural area of South Central Florida. This area has higher rates of teenage pregnancy and poverty and lower educational attainment in comparison with state averages. Method: Propensity scores and nearest-neighbour matching without replacement were used to select a group of girls who did not participate in the programme but were comparable to participants. Programme participants were compared to the propensity score–selected controls on key outcomes using hierarchical linear regression. Results: Findings indicate that at follow-up, girls who participated in GO GIRLS had attitudes more accepting of delaying sexual intercourse than controls. However, participants did not differ in their levels of sex refusal skills at follow-up. Conclusion: This study shows that the GO GIRLS programme has promise for at-risk, rural girls and highlights where future evaluation research is needed.

Integrating translational neuroscience to improve drug abuse treatment for adolescents.

Adolescence is an exciting and challenging period of maturation, rapid brain development, and developmental changes in neurobiological, neurocognitive, and neurobehavioral processes. Although behavioral therapies available for adolescent substance abuse have increased, effectiveness research in this area lags considerably behind that of clinical research on treatment for drug-abusing adults. Behavioral treatment approaches show significant promise for treating drug-abusing adolescents, but many have not incorporated innovations in neuroscience on brain development, cognitive processes, and neuroimaging. Linking developmental neuroscience with behavioral treatments can create novel drug abuse interventions and increase the effectiveness of existing interventions for substance-abusing adolescents. Contemporary research on brain development, cognition, and neuroscience is ripe for translation to inform developmentally sensitive drug abuse treatments for adolescents. Neuroscientists and interventionists are challenged to build mutual collaborations for integration of neuroscience and drug abuse treatment for adolescents.