Kaess et al. BMC Public Health 2011, 11:597 http://www.biomedcentral.com/1471-2458/11/597 R E S E A R C H A R T I C L E Open Access Explaining gender differences in non-fatal suicidal behaviour among adolescents: a population-based study Michael Kaess1,4*, Peter Parzer1, Johann Haffner1, Rainer Steen2, Jeanette Roos3, Martin Klett2, Romuald Brunner1 and Franz Resch1 Abstract Background: While suicide is the second leading cause of death among young people in most industrial countries, non-fatal suicidal behaviour is also a very important public health concern among adolescents. The aim of this study was to investigate gender differences in prevalence and emotional and behavioural correlates of suicidal behaviour in a representative school-based sample of adolescents. Methods: A cross-sectional design was used to assess suicidal behaviour and various areas of emotional and behavioural problems by using a self-report booklet including the Youth Self-Report. One hundred sixteen schools in a region of Southern Germany agreed to participate. A representative sample of 5,512 ninth-grade students was studied. Mean age was 14.8 years (SD 0.73); 49.8% were female. Results: Serious suicidal thoughts were reported by 19.8% of the female students and 10.8% of the females had ever attempted suicide. In the male group, 9.3% had a history of suicidal thoughts and 4.9% had previously attempted suicide. Internalizing emotional and behavioural problems were shown to be higher in the female group (difference of the group means 4.41) while externalizing emotional and behavioural problems slightly predominated in male students (difference of the group means -0.65). However, the total rate of emotional and behavioural problems was significantly higher in the adolescent female group (difference of the group means 4.98). Using logistic regression models with suicidal thoughts or attempted suicide as dependent variables, the pseudo-R2 of gender alone was only 2.7% or 2.3%, while it was 30% or 23.2% for emotional and behavioural problems measured by the YSR syndrome scales. By adding gender to the emotional and behavioural problems only an additional 0.3% of information could be explained. Conclusions: The findings suggest that gender differences in non-fatal suicidal behaviour among adolescents can to a large extent be explained by the gender differences in emotional and behavioural problems during this age. Keywords: suicidal behaviour, suicide, gender, adolescence, emotional and behaviour problems Background Suicide and non-fatal suicidal behaviour are both well- recognized public health problems in young people [1,2]. Whereas the prevalence of suicide and suicidal behaviour remains relatively low before puberty [3], ado- lescent suicide is one of the leading causes of death in the teenaged group [4]. In Europe, suicide is the second * Correspondence: michael.kaess@unimelb.edu.au 1Department of Child and Adolescent Psychiatry, Centre of Psychosocial Medicine, University of Heidelberg, Heidelberg, Germany Full list of author information is available at the end of the article leading cause of death in male and female adolescents [5]. In the USA, suicide is reported to be the third lead- ing cause of death after accidents and homicides [6]. According to the findings of a WHO multi-centre study conducted in young people 15 to 24 years of age, the increase in suicide has been shown to be associated with an increase in suicide attempts [7]. Results of a systema- tic review of 128 studies on the prevalence of suicidal phenomena in adolescents revealed that, on average, 9.7% (95% CI 8.5 to 10.9) of adolescents reported to have attempted suicide while even 29.9% (95% CI 26.1 © 2011 Kaess et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.