Non-Suicidal Self-Injury and Indirect Self-Harm among Danish High School Students

Background: Non-suicidal self-injury (NSSI) and indirect self-harm are prevalent among adolescents, but it is rare to see them described as related topics.Objective: The purpose of this study was to investigate whether there is a correlation between the frequencies of NSSI and indirect self-harm (e.g., eating problems, alcohol and drug use) and how this may be influenced by gender.Method: Questionnaires about NSSI (e.g., cutting, burning, scratching, hitting oneself) and indirect self-harm were distri­buted to high school students in theCopenhagen area (N = 5650; response rate 53%; females 60.8%).Results: A total of 21.5% of the survey respondents had engaged in NSSI (lifetime prevalence), and 16.2% had practiced NSSI within the previous year. Gender differences in NSSI methods were identified. A total of 53.9% of the students had engaged in one or more types of indirect self-harm. The correlation between NSSI and indirect self-harm is twice as high for males (0.44; P < .001) as compared with females (0.20; P < .001).Conclusions: Clinicians must be aware of both NSSI and indirect self-harm. A positive correlation is seen, especially among young males. Males often perform other kinds of NSSI as compared with females, and clinicians must look for gender-specific signs of NSSI. It is argued that NSSI can be perceived as a “social pathology,” but it is also indicated that NSSI and indirect self-harm can be evaluated as an expression of ordinary behavior among modern high school students that must not be medicalized.