Association between cumulating substances use and cumulating several school, violence and mental health difficulties in early adolescents.

Multiple substances (alcohol, tobacco, cannabis and other illicit drugs (OID)) have been frequently used in early adolescents maybe due to school, violence and mental-health difficulties. We investigated the associations between substance-use patterns and related difficulties among 1559 middle-school adolescents from north-eastern France (mean age 13.5 ± 1.3). They completed a questionnaire including socioeconomic features, school, violence and mental-health difficulties (school grade repetition, sustained physical/verbal violence, sexual abuse, perpetrated violence, poor social support, depressive symptoms and suicide attempt; cumulated number noted SVMD) and the time of their first occurrence during the life course. Data were analyzed using logistic and negative binomial regression models. Alcohol, tobacco, cannabis and OID use affected 35.2, 11.2, 5.6 and 2.8% of the subjects respectively. The risk of using tobacco only, alcohol and tobacco, alcohol plus tobacco and cannabis, or all alcohol, tobacco, cannabis and OID strongly increased with the SVMD (socioeconomic features-adjusted odds ratio reaching 85). The risk began in early years in middle schools and then steadily increased, more markedly for elevated SVMD. Exposure to several SVMDs may be a transmission vector towards the substance use, starting mostly with alcohol/tobacco, and then shifting to cannabis/OID. These findings help to understand substance-use risk patterns and identify at-risk adolescents.