Behavioral Health, Mental Health, Substance Abuse
Illicit and nonmedical drug use among young adults: An 8-year longitudinal analysis from college entry through age 25
(School of Public Health (UMD) Behavioral and Community Health Doctoral Student)
Background: Substance use can compromise college student health, safety, and academic performance. Drawing on Ecological Systems Theory, this study used longitudinal data to examine how substance use might fluctuate as college students transition into young adulthood. Methods: Using data from a longitudinal cohort study of 1,253 first-year college students at a single public university, these analyses estimated: 1) the annual prevalence of use of ten types of drugs; 2) the cumulative lifetime prevalence of each drug used; and 3) the incidence (i.e., “new cases”) of drug use during Years 1-4 of the study (i.e., during college) and Years 5-8 of the study (i.e., post-college). Data were gathered via personal interviews. Past-year drug use was measured annually using standard questions for marijuana, hallucinogens, inhalants, cocaine, ecstasy, amphetamines, heroin, and nonmedical use of prescription stimulants, analgesics, and tranquilizers. Descriptive statistics were used to estimate prevalence and incidence. Results: The annual prevalence of use for marijuana, prescription stimulants, and prescription analgesics increased from college entry through modal age 20, and then declined through age 25. Hallucinogens and cocaine followed a similar trajectory, but a small increase was detected at modal age 24. Heroin, cocaine, ecstasy, and prescription tranquilizers all had relatively low lifetime prevalence estimates at college entry, but the cumulative lifetime prevalence for these drugs increased substantially by Year 8. Marijuana was the most commonly used drug during all eight years. Comparing incidence rates during Years 1-4 with Years 5-8 revealed surprising findings that indicate that risk for becoming a new marijuana user persists into the mid-20s. Significance: Findings suggest that colleges should provide substance use screening and interventions throughout the college years to mitigate consequences. In addition, drug prevention efforts for young adults should also continue after graduation, as a substantial proportion of participants delayed drug use initiation until post-college.