This work presents the results obtained on applying a drug-abuse prevention programme, an adaptation of Botvin's 'Life
skills training' programme. The initial sample comprised 1029 adolescents from five secondary schools in the city of
Santiago de Compostela (NW Spain), distributed in three experimental conditions, two treatment, in which the programme
was applied by teachers or by members of the research team, and a control condition. The article presents the results on
the use of different drugs over four years of follow-up. The results obtained show how for the treatment condition lower
levels of tobacco and alcohol consumption are found after a year of follow-up. In later evaluations these effects fade, but
important differences emerge in the use of other drugs, such as cannabis, tranquillizers or amphetamines.