Data on single & multiple addiction-risk behaviours & suicidal behaviour were obtained from a large sample of Dutch secondary school students, aged 16-19 years. The number of addiction-risk behaviours reported by the adolescents showed an almost linear increasing relation with the percentage of suicide attempters. The results suggest that suicidal behaviour & addiction-risk behaviours should both be regarded as part of a complex interaction of multiple behavioural problems. (11 refs.)