Valerie Johnson, PhD¹, Robert J. Pandina, PhD¹, and Steven Buyske, PhD². (1) Center of Alcohol Studies, Rutgers University, 607 Allison Rd., Piscataway, NJ 08854, 732-445-2424, vjohnson@rci.rutgers.edu, (2) Statistics Department, Rutgers University, 110 Frelinghuysen Rd., Piscataway, NJ 08854

This study assessed adult comorbid conditions among subjects categorized into one of several longitudinal marijuana use trajectories. Subjects were 1380 adolescents, interviewed when they were 12, 15 or 18 years old and again at four additional times. It was found that 78% had used marijuana at some time during their life. Using growth curve analysis and measures of frequency and consequences of use, multiple use patterns were found. Analyses were conducted separately by age and gender. Up to four use trajectory groups were found, and generally reflected 1) low level use at age 15 with cessation by young adulthood, 2) peak levels of use at age 18-21 with cessation by 24, 3) high levels of use from ages 15-25 with cessation by age 28 and 4) sustained high levels of use from 15-31. Depression was measured using subscales of the Inventory to Diagnose Depression. Negative affect was measured by stressful life events, stressful conditions, use of negative coping, and anxiety. Alcohol abuse was measured using DSM criteria. It was generally found that subjects who used marijuana at high levels throughout young adulthood, also reported the highest levels of depressive symptoms, alcohol abuse, and negative affect. While subjects who ceased or decreased their use in adulthood exhibited lower levels of comorbid symptomologies, they exhibited some detriments. We conclude that marijuana use patterns are critical determinants of adult outcomes. (Supported by NIDA 17552, 03395; NIAAA 05823, 11699; Peter F. McManus Charitable Trust).

Learning Objectives: At the conclusion of the session, the participant (learner) in this session will be able to

• Learn a means to characterize marijuana use over multiple test occasions
• Understand the developmental differences in marijuana use among males and females
• Understand the association of marijuana use and subsequent comorbid conditions
• Identify marijuana user subgroup differences in outcomes
• Discuss associations between comorbid conditions and marijuana use
• List the types of marijuana users found in a community sample
• Articulate the differences in behavior patterns for males and females of various ages
• Articulate the marijuana use pattern characteristics found for subjects over a 20-year period

Keywords: Marijuana, Youth

Presenting author's disclosure statement:
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.