From psychiatric symptom to diagnostic category: self-harm from the Victorians to DSM-5

It is rare that a symptom becomes a disease entity. 'Self-harm' is now a full-fledged diagnostic category for DSM-5. The existing literature of the topic posits that it is a trans-historical psychiatric category and that examples of self-harm can be found from the earliest written records, which is part of the underlying argument for its inclusion in DSM-5. But how old is self-harm and indeed what defines 'self-harm' historically and culturally?