Bullying behaviour and criminality: a population-based follow-up study of adolescent psychiatric inpatients in Northern Finland

Abstract

The recent school shootings in Europe and the USA have raised the question of whether victims of bullying run an increased risk of committing violent crimes later in life, but scientific research in this area is scarce. The aim of this work was to investigate whether bullying behaviour is associated with later criminal offences committed in adolescence and young adulthood. We studied a sample of 508 Finnish adolescents (age 12-17 years) admitted to psychiatric inpatient care between April 2001 and March 2006. Data on crimes committed and the age of onset of criminal activity were extracted from the official criminal records of the national Legal Register Centre in October 2008. The Schedule for Affective Disorder and Schizophrenia for School-Age Children, Present and Lifetime (K-SADS-PL) was used to define bullying status, and to obtain DSM-IV-based psychiatric diagnoses for the adolescents. Violent crimes were statistically significantly associated with bullying behaviour, but not non-violent crimes. Furthermore, being a bully was predictive of an early onset of severe violent offences. When controlled for the psychiatric diagnoses of the adolescents, we observed decreased likelihood of criminality among victims. Thus bullying others may increase the risk of violent offences, while being a victim is not a risk factor for criminality.