This guide is designed to help work effectively with young people that have complex mental health issues. It provides guidance to understand and respond to emerging personality disorder, trauma history, self-harm and suicidal behaviour, and other difficulties with identity, emotions and relationships. The aim is to assist all people interested in improving the mental health of young people. Counsellors, health staff, welfare workers, teachers and school administrators often require additional information to effectively identify, respond, support and refer young people with severe and complex mental health concerns, particularly personality disorder. A further goal is to help those who care for young people to respond to challenging behaviours common in this population, for example, self-harm.