Our results suggest that early drug use is associated with and predicts later psychiatric disorders. Preventive implications stem from the importance of studying a range of psychiatric disorders in the context of substance use assessed over a wide age range.

The purpose of this study was to identify distinct trajectories of cigarette smoking from ages 14 to 32, and to examine adolescent personality factors that distinguish trajectories of smoking behavior. Participants (N=975) were randomly selected and followed prospectively since 1975. Follow-up data on cigarette use and personality and behavioral attributes were collected at five points in time, using structured interviews given in private by trained interviewers. Of these subjects, 746 comprised the cohort used in this study. Growth mixture modeling identified five smoking trajectory groups: nonsmokers, occasional smokers, late starters, quitters, and heavy/continuous smokers. Adolescent personality and behavioral risk factors such as lower ego integration, more externalizing behavior, and lower educational aspirations distinguished the trajectory groups. No gender differences were noted. The findings supported the hypotheses indicating multiple distinct trajectory groups of smoking behavior. Smoking behavior appeared in early adolescence and most often continued into adulthood. Emotional difficulties (i.e., lower ego integration), externalizing behavior, and lower educational aspirations in early adolescence were associated both with smoking at an early age and with continuing to smoke into the thirties. To be more effective, smoking prevention programs should target personality and behavioral variations, before smoking becomes habitual, particularly focused on characteristics reflecting behavioral problems as manifested in emotional difficulties, externalizing behavior, and low educational aspirations in early adolescence. The implications for research, prevention, and treatment are discussed.

This study tested a developmental model of pathways to risky sexual behavior among South African adolescents. Participants comprised 633 adolescents, 12-17 years old, recruited from households in Durban, South Africa. Data were collected using in-person interviews. Topics included adolescents' sexual behaviors, household poverty levels, vulnerable personality and behavioral attributes, parent-child relations, and deviant peers. Structural equation modeling was used to assess the pathways to risky sexual behavior among the adolescents. The goodness-of-fit index (GFI) was .93. One major pathway indicated that family poverty was associated with difficulty in the parent-child relationship. This was related to vulnerable personality and behavioral attributes and to association with deviant peers, which, in turn, were related to risky sexual behavior. Findings suggest that poverty, parent-child relations, personality and behavioral vulnerabilities, and peer influences should be among factors addressed by prevention and intervention programs to reduce sexual risk behaviors by South African adolescents.

In this prospective longitudinal study, the authors investigated the association between marijuana use over a period of 13 years and subsequent health problems at age 27. A community sample of 749 participants from upstate New York was interviewed at mean ages of 14, 16, 22, and 27 years. Marijuana use over time was significantly associated with increased health problems by the late twenties, including respiratory problems, general malaise, neurocognitive problems, and lower academic achievement and functioning. Effective prevention and intervention programs should consider the wide range of adverse physiological and psychosocial outcomes associated with marijuana use over time.