Prevalence and incidence of drug use among college students: an 8-year longitudinal analysis.

Background: Drug use among college students is associated with adverse academic and health outcomes and risks to personal safety.

Objectives: This study utilized data from a longitudinal study to estimate annual prevalence, cumulative lifetime prevalence, and incidence of ten types of drug use during the eight years after college entry and the average age of onset of each drug used.

Methods: Participants (N = 1,253; 52% female) were young adults who were originally enrolled as first-time, first-year students at a university in the mid-Atlantic US. Annual personal interviews gathered data about the use of seven illicit drugs and three prescription drugs used nonmedically. Annual follow-up rates ranged from 76 to 91%.

Results: Marijuana was the most commonly used drug in every year of the study, with the highest annual prevalence estimates in Year 3 (47%). In Year 8, when the modal age of participants was 25, 29% used marijuana during the past year. Nonmedical use of prescription drugs was more prevalent during college than in the later years of the study. Although the prevalence of cocaine and ecstasy use was low (cumulative prevalence estimates of 17% and 13% respectively), incidence for these drugs was particularly high in the later years of the study.

Conclusion: Drug use is prevalent among college students, and drug use persists among young adults, even after many have graduated college. More attention should be directed at identifying and intervening with students at risk for drug use to mitigate possible academic, health, and safety consequences.