[Tobacco, alcohol and illegal drug consumption among adolescents and the relationship with lifestyle and environment].
To identify the age at which adolescents first experiment with tobacco, alcohol and illegal drugs and to identify the relationship between consumption of these substances and lifestyle and environment. Cross-sectional descriptive study based on a survey of 2,178 adolescents aged 12-16 years old from Cantabria (Spain). Tobacco was considered a drug by 80.4 % of the adolescents. Forty-four percent had smoked at some time and 19.3 % were smokers. Alcohol was not considered a drug by 44.5 %, 69.2 % had drunk alcohol at some time and 37 % drank regularly. Most of the adolescents (92.9 %) drank at weekends and 88 % drank all the spirits surveyed. The adolescents were introduced to this habit by friends (54.1 %) and relatives (16.4 %). Forty-six percent of those who drank regularly had got drunk once or more in the previous 6 months. At the age of 15 years, 29.4 % smoked and 61.8 % drank alcohol regularly. An association with illegal drugs was less common; 10.2 % smoked hashish. Consumption of all these substances was associated with greater age, living in an environment in which these substances were consumed and with certain forms of leisure activity. Logistic regression analysis revealed that considering tobacco and alcohol as drugs protected adolescents against their consumption and that consuming other drugs, getting drunk and being in a consumer environment were risk factors for consumption. Contact with illegal drugs, alcohol and tobacco starts early in adolescence. Levels of consumption are worrying. Environment and lifestyle are closely associated with risk factors for consumption.