Developmental Trajectories of Adolescent Substance Use

ABSTRACT

Longitudinal data from 746 adolescents in Toronto, Canada (54% females), was gathered in eight waves over seven years (1995 through 2001), beginning when the youths were 10 to 12 years old (mean age = 11.8, SD = 1.2 years). Five trajectories of substance use were identified: chronic-high, childhood onset-rapid high, childhood onset-moderate, adolescent onset-moderate, and non-use groups. Late childhood risk factors for substance use included delinquency, academic disengagement, low parental monitoring, and associating with substance-using peers. Externalizing problems emerged as an additional risk factor for the most severe substance-using group during adolescence. Of note, the childhood onset-moderate group reported only moderate levels of substance use during adolescence despite high levels of risk during late childhood. Implications for prevention of and intervention for substance use are discussed.

KEYWORDS:

• adolescent development
• developmental trajectories
• substance use