Trajectory Classes of Externalizing and Internalizing Symptoms to Adolescent Gambling Participation: An Exploratory Study.

Engagement in underage gambling remains a public health concern. Risk factors for the development of gambling behaviours in adolescence include the presence of externalizing and/or internalizing problems. This study aims to better understand the role of co-occurrence between externalizing and internalizing symptoms from childhood to adolescence in adolescent gambling. Participants were drawn from an ongoing longitudinal study of children with and without early conduct problems. Externalizing and internalizing problems were measured annually using teacher and parent reports. Gambling behaviours were measured using self-report when participants were approximately 15 years old. Latent class growth trajectory analyses identified five mental health trajectory classes: (1) a co-occurring trajectory characterized by stable clinical levels of both externalizing and internalizing problems, (2) an externalizing trajectory characterized by stable high clinical levels of externalizing problems, (3) an internalizing trajectory characterized by stable at-risk levels of internalizing problems, (4) an at-risk externalizing trajectory characterized by decreasing levels of externalizing problems, and (5) a non-clinical trajectory. Invariance analyses suggested that this model remained valid in both boys and girls. Logistic regression analyses suggested that youth who belonged in the externalizing trajectory reported a greater likelihood of past-year gambling behaviours when compared to youth who belong in the comorbid trajectory. No other mental health trajectory was significantly associated with adolescent gambling. Stable high externalizing behaviours in development appear to increase one's risk of gambling behaviours in adolescence. Efforts to target these throughout development could help decrease one's future risk of engaging in these behaviours.