The aim of this study was to analyse the contribution of social support from family, friend and school (teacher and classmate) contexts in substance use (tobacco and alcohol use) and well-being (life satisfaction and health-related quality of life). Participants were 5,784 Portuguese and 22,610 Spanish adolescents aged 11 to 16 years, from the 2014 edition of the Health Behavior in School-aged Children (HBSC) study in Portugal and Spain. Results showed that for a higher life satisfaction, family (p < .001, partial η2 = .032), teacher (p < .001, partial η2 = .018) and classmate (p < .001, partial η2 = .031) support were important in Portugal, and family (p < .001, partial η2 = .056) and friend (p < .001, partial η2 = .015) support in Spain. Similarly, for a better health-related quality of life, all the social support variables were relevant in Portugal (family: p < .001, partial η2 = .063; teacher: p < .001, partial η2 = .032; classmate: p < .001, partial η2 = .054; friend: p < .001, partial η2 = .034) and in Spain (family: p < .001, partial η2 = .054; teacher: p < .001, partial η2 = .014; classmate: p < .001, partial η2 = .018; friend: p < .001, partial η2 = .040). In contrast, only family support (p < .001, partial η2 = .014) was relevant in Portugal for tobacco use. Therefore, social support was more relevant for adolescent well-being than for adolescent substance use, and the most relevant source of support was family support, in both Spain and Portugal.

This research is part of the 2006 edition of the Health Behavior in School-aged Children (HBSC) study. The data presented were composed of a sample of 15942 Spanish adolescents ranging from 13 to 18 years of age. The instruments used included a variety of questions related to substance consumption among adolescents, their bio-psycho-social adjustment and developmental contexts, all of which are part of the HBSC study instrument bank. Through classification analysis, as well as significance and effect size tests, we obtained relevant information about the current epidemiology of substance consumption among Spanish adolescents. These results are representative of the Spanish adolescent population which allows the typical risk profile attributed to young people to be clarified. A gradual adjustment can be seen in terms of substance consumption levels in youth and that same level in their friends. Likewise, the analysis of the developmental context (family, friends and school) provides important information when it comes to preventing substance consumption, thus showing the advantages that coherence and connection have between the different environments where youth live, grow up and develop.