A relationship between alcohol use and aggression is well-established; however, less is known about how these factors develop and influence each other over time. This study examined the immediate and delayed effects of alcohol use on aggression during adolescence. Alcohol use and aggression were measured in a subset of students (n = 1560) from the Climate and Preventure study, Australia. Participants completed self-report surveys across five assessments (ages 13, 13.5, 14, 15 and 16). In a two-stage analysis, parallel and auto-regressive latent growth curve models were applied to investigate person-specific trajectories (or between-person effects) of alcohol use and aggression and identify the time-varying impact (or within-person effects) of alcohol use on aggression. Average alcohol consumption increased between ages 13 and 16, while average aggression levels decreased over time. Overall growth in alcohol use was positively related to heightened aggression at age 16, and vice versa. Spikes (time-varying increases) in alcohol use were linked to corresponding increases in aggression at each time point. There was evidence of a prospective effect where aggression was associated with hazardous alcohol use a year later, but no evidence that alcohol use was associated with subsequent aggression. Change in hazardous alcohol consumption and aggression beginning early in adolescence are interrelated and are predictive of one another at age 16. The time-varying effects of alcohol on aggression appear to be immediate rather than delayed; however, there is evidence for a prospective relationship where aggression influences later alcohol use. Implications for the timing and nature of novel harm reduction intervention approaches for young people are discussed.
Keywords: Adolescence; Aggression; Alcohol; Longitudinal; Substance use.