Self-harming and suicidal behaviour are both well-recognized problems during adolescence. While prevalence rates are very high and still rising in most western countries, there is an extensive need for understanding childhood developmental aspects, personality factors and psychological correlates of self-harm and suicidality. Additionally, specific and effective prevention should be established regarding self-harming and suicidal behaviour as one of the largest concerns of public health during this period of life.

To investigate the prevalence and the associated psychological and social factors of self-harming behaviour in adolescents. To evaluate a school-based intervention aimed at reducing self-harming behaviour in adolescents.

In the years 2005 and 2010 we performed one population-based, cross-sectional study including a sample of 5,759 ninth-grade students and one randomized-controlled, school-based prevention study within the large EU-consortium (SEYLE) comprising a sample-size of 1,387 students on self-harming and suicidal behaviour in Heidelberg.

The data suggest that there is a strong link between social factors and occasional self-injurious behavior and, especially in repetitive self-injurious behaviour, that there is a strong association between self-injurious behaviour and suicidal behaviour as well as self-injurious behaviour and emotional and behavioural problems. Preliminary results of the randomized-controlled prevention study could reveal a decrease of self-harming behaviour in adolescents in the short-term as well as long-term-follow-up.

The results support a need to investigate the possible neurobiological underpinnings as well as social factors of self-harming behaviour within a longitudinal model.