Time-Specific Associations and Developmental Trajectories of Co-occurring Substance Use and Disordered Eating among Adolescent Girls

Despite the established co-prevalence of substance use (SU) and disordered eating (DE), few longitudinal studies have sought to examine their shared development. Findings have been inconsistent within the extant literature. This may be attributable in part to several methodological aspects, including overlooking distinct psychopharmacological properties of common substances of abuse, examining only between-person relations, and failing to account for shared risk factors. The current study sought to address these gaps by applying latent curve models with structured residuals (LCM-SR) to a preexisting, national sample of adolescent girls followed into adulthood, Add Health. In Aim 1, between-person effects examined the simultaneous development of alcohol, tobacco, and marijuana use and DE behaviors in substance-specific models. In Aim 2, bivariate latent curve models were expanded to account for within-person effects (LCM-SR) in order to examine the potentially bidirectional, prospective relationship between use of a specific substance and DE. Lastly, models accounted for shared developmental risk factors. Findings of the current study demonstrate preliminary evidence of substance-specific effects with DE emerging in adolescence. Across model-building steps, DE engagement in early adolescence was significantly associated with growth in tobacco use and marginally associated with marijuana use. Appetitive side-effects of both substances may link use with DE behaviors and enhance instrumental use for weight control. Significant associations did not emerge between alcohol and DE, and results of the conditional model indicate this co-occurrence is best explained by third variable mechanisms. Implications for prevention are discussed.