ABSTRACT
The purpose of this paper is to provide an estimate of the prevalence and distribution of non-suicidal self-injury among Danish high school students. In a questionnaire study in seven high schools in the Copenhagen area (n = 2 864), we find a lifetime prevalence of 21.5% with a little preponderance of women, but it seems that men are involved in a more persistent and intense form of self-injurious behaviour. More men (14.7%) than women (6.2%) have injured themselves more than 20 times in the last year. Fewer men than women did not harm themselves in the last year. We conclude that it is important to be aware of self-harm both among women and men in high schools to avoid escalation. Copyright © 2011 John Wiley & Sons, Ltd.