Marijuana use patterns among African-American middle-school students: a longitudinal latent class regression analysis.

The aim of this paper was to describe patterns of marijuana involvement during the middle-school years from the first chance to try marijuana down through the early stages of experiencing health and social problems from marijuana use in a sample of African-American adolescents. A total of 488 urban-dwelling African-American middle-school students were interviewed in sixth, seventh and eighth grades as part of a longitudinal field study. Longitudinal latent class models were used to identify subgroups (classes) of adolescents with similar patterns of marijuana involvement. Three classes were identified; little or no involvement (prevalence 85%, 71%, 55% in sixth, seventh and eighth grade, respectively), marijuana exposure opportunity (12%, 19% and 26%), and marijuana use and problems (2%, 9% and 19%). High levels of aggressive/disruptive behavior exhibited as early as first grade and moderate to high levels of deviant peer affiliation were associated with an increased risk of marijuana exposure opportunities in middle-school. Moderate to high levels of aggressive/disruptive behavior and deviant peer affiliation, moderate to low levels of parent monitoring and high levels of perceived neighborhood disadvantage were associated with an increased risk of marijuana use and problems. Significant interactions with grade provided evidence that the influences of parent monitoring and neighborhood disadvantage decrease through the middle-school years. Although not statistically significant, the magnitude of the effects of deviant peer affiliation on marijuana use and problems increased two-fold from sixth to eighth grade. These findings highlight the importance of marijuana exposure opportunities in the pathway to marijuana use and problems and the potential to intervene on behaviors exhibited as early as first grade. It also underscores the importance of developing interventions that are sensitive to the strong influence of parents at entry into middle-school and the shift to peer influences by the end of middle-school.

A comparison of girls' and boys' aggressive-disruptive behavior trajectories across elementary school: prediction to young adult antisocial outcomes.

Multiple group analysis and general growth mixture modeling was used to determine whether aggressive- disruptive behavior trajectories during elementary school, and their association with young adulthood antisocial outcomes, vary by gender. Participants were assessed longitudinally beginning at age 6 as part of an evaluation of 2 school-based preventive programs. Two analogous trajectories were found for girls and boys: chronic high aggression- disruption (CHAD) and stable low aggression- disruption (LAD). A 3rd class of low moderate aggression- disruption (LMAD) for girls and increasing aggression- disruption (IAD) for boys also was found. Girls and boys in analogous CHAD classes did not differ in trajectory level and course, but girls in the CHAD and LAD classes had lower rates of antisocial outcomes than boys. Girls with the LMAD trajectory differed from boys with the IAD trajectory.

Mediators of the stress-substance-use relationship in urban male adolescents.

Exposure to chronic or severe acute stressors throughout the lifespan has been linked with numerous negative behavioral, emotional, cognitive, and physical consequences. Adolescence is considered to be a particularly vulnerable period given that the brain is experiencing dramatic developmental change during this time. The present study examined a sample of adolescents (N=125) considered to be at high risk for stress exposures and drug use by virtue of their environment and low income levels to identify possible neurocognitive (i.e., impulsivity, delay of gratification, emotional perception, and risky decision-making) and social competency mechanisms that may mediate this relationship. Using Mplus, a mediational model was tested using full information maximum likelihood estimates. Risky decision-making and poor social competency skills were related to previous stressful experiences; however, only social competencies mediated the effect of stressors on reports of past year marijuana, alcohol, and polydrug use. As such, stress appears to exert its negative impact through alterations in abilities to generate and execute prosocial decisions and behaviors. Interventions that directly address the effects of stress on social competencies may be especially important for children who have experienced adversity including those exposed to parental divorce, parental psychopathology, neglect or abuse, parental death, and poverty.

Neurocognitive skills moderate urban male adolescents' responses to preventive intervention materials.

The present experiment was designed to determine whether individual variation in neurobiological mechanisms associated with substance abuse risk moderated effects of a brief preventive intervention on social competency skills. This study was conducted in collaboration with the ongoing preventive intervention study at Johns Hopkins University Prevention Intervention Research Center (JHU PIRC) within the Baltimore City Public Schools. A subsample (N = 120) of male 9th grade students was recruited from the larger JHU study population. Approximately half of the participants had a current or lifetime diagnosis of CD while the other half had no diagnosis of CD or other reported problem behaviors. Measures of executive cognitive function (ECF), emotional perception and intelligence were administered. In a later session, participants were randomly assigned to either an experimental or control group. The experimental group underwent a facilitated session using excerpted materials from a model preventive intervention, Positive Adolescent Choices Training (PACT), and controls received no intervention. Outcomes (i.e., social competency skills) were assessed using virtual reality vignettes involving behavioral choices as well as three social cognition questionnaires. Poor cognitive and emotional performance and a diagnosis of CD predicted less favorable change in social competency skills in response to the prevention curriculum. This study provides evidence for the moderating effects of neurocognitive and emotional regulatory functions on ability of urban male youth to respond to preventive intervention materials.

When the course of aggressive behavior in childhood does not predict antisocial outcomes in adolescence and young adulthood: an examination of potential explanatory variables.

Theoretical models and empirical studies suggest that there are a number of distinct pathways of aggressive behavior development in childhood that place youth at risk for antisocial outcomes in adolescence and young adulthood. The prediction of later antisocial behavior based on these early pathways, although substantial, is not perfect. The goal of the present study was to identify factors that explain why some boys on a high-risk developmental trajectory in middle childhood do not experience an untoward outcome, and, conversely, why some boys progressing on a low-risk trajectory do become involved in later antisocial behavior. To that end, we explored a set of theoretically derived predictors measured at entrance to elementary and middle school and examined their utility in explaining discordant cases. First-grade reading achievement, race, and poverty status proved to be significant early predictors of discordance, whereas the significant middle-school predictors were parent monitoring, deviant peer affiliation, and neighborhood level of deviant behavior.