ABSTRACT:Objective: This study describes the sexual behavior among students who participated in the National Adolescent School-based Health Survey (PeNSE) 2012 and investigates whether social inequalities, the use of psychoactive substances and the dissemination of information on sexual and reproductive health in school are associated with differences in behavior. Methodology: The response variable was the sexual behavior described in three categories (never had sexual intercourse, had protected sexual intercourse, had unprotected sexual intercourse). The explanatory variables were grouped into socio-demographic characteristics, substance use and information on sexual and reproductive health in school. Variables associated with the conduct and unprotected sex were identified through multinomial logistic regression, using "never had sexual intercourse" as a reference. Results: Over nearly a quarter of the adolescents have had sexual intercourse in life, being more frequent among boys. About 25% did not use a condom in the last intercourse. Low maternal education and work increased the chance of risky sexual behavior. Any chance of protected and unprotected sex increased with the number of psychoactive substances used. Among those who don't receive guidance on the prevention of pregnancy in school, the chance to have sexual intercourse increased, with the largest magnitude for unprotected sex (OR = 1.41 and OR = 1.87 ). Conclusion: The information on preventing pregnancy and STD/ AIDS need to be disseminated before the 9 th grade. Social inequalities negatively affect risky sexual behavior. Substance use is strongly associated with unprotected sex. Information on the prevention of pregnancy and STD/AIDS need to be disseminated early.

Results reinforce the association between social disadvantages and experimenting and regular smoking. In addition, the use of other tobacco products is worthy of attention and may lead to regular smoking.

ABSTRACT:Objective: To evaluate the association between the consumption of psychoactive substances (tobacco, alcohol and illicit drugs) and demographic variables, mental health and family context among school-aged children. Methods: The National Adolescent School-based Health Survey was held with a national sample of 109,104 students. Data regarding demographic variables, family background and mental health were collected. Logistic regression was used to evaluate the associations of interest. Results: Multivariate analyses showed that alcohol consumption was higher among girls, drug experimentation was more frequent among boys and that there was no difference between sexes for smoking. Being younger and mulatto were negatively associated with the use of tobacco, alcohol and illicit drugs. Also negatively associated with such risk behaviors were characteristics of the family context represented by: living with parents, having meals together and parental supervision (when parents know what the child does in their free time). Moreover, characteristics of mental health such as loneliness and insomnia were positively associated with use of tobacco, alcohol and illicit drugs. Not having friends was positively associated with use of tobacco and illicit drugs and negatively associated with alcohol use. Conclusions: The study shows the protective effect of family supervision in the use of tobacco, alcohol and drugs and, on the contrary, the increasing use of substances according to aspects of mental health, such as loneliness, insomnia and the fact of not having friends. The study's findings may support actions from health and education professionals, as well as from the government and families in order to prevent the use of these substances by adolescents.