ABSTRACT
How common is self-harm? The answer to this question is not straightforward. It depends on the definition of self-harm – whether researchers want to establish the prevalence of suicide attempts, suicidal and non-suicidal self-harm or just non-suicidal self-harm,1 detection tools – whether these are anonymised, self-reported or interviewer-administered;2 survey type – cross-sectional, retrospective or prospective;1,3 informants – usually either adolescents or their parents,1,3 age of participants4 and population studied – general population, clinical population (inpatients or outpatients) or adolescents presenting to emergency departments.3
