Polydrug use trajectories and differences in impulsivity among adolescents

Background/Objective: Although alcohol, tobacco and cannabis are the most widely consumed drugs, sparse data exist regarding polydrug use in adolescents and its relationship with impulsivity. This study aims to identify trajectories of polydrug use and analyze differences in impulsivity between them. Method: A total of 1,565 adolescents (54.4% males; mean age = 13.02, SD = 0.57) were annually assessed over three years using the Barratt Impulsiveness Scale, the Zuckerman Impulsive Sensation Seeking Scale, a Stroop Test and a Delay Discounting Task. Frequency of alcohol, tobacco, and cannabis use, intoxication episodes and problem drinking were also assessed. Polydrug trajectories were identified using latent class mixed modelling. To examine differences in self-reported and behavioral impulsivity two mixed multivariate analyses of covariance were used. Results: Three trajectories of substance use were found. The 'Experimental use' and the 'Early use' trajectories presented the lowest and highest impulsivity, respectively. Substance use increases in the 'Telescoped used' trajectory were associated with parallel increases in impulsivity. Conclusions: individuals with divergent patterns of substance use during adolescence differ in their impulsiveness, primarily in general impulsivity and sensation seeking. Present findings suggest the relevance of these facets as possible targets for interventions preventing the onset and escalation of substance use. (C) 2018 Published by Elsevier Espana, S.L.U. on behalf of Asociacion Espanola de Psicologia Conductual.