How do mental illnesses manifest? How are they treated? How can a professional approach to working with people with mental illnesses be shaped? What difficulties and challenges does this work entail? These are the questions that (aspiring) professionals in social work are repeatedly confronted with. Students of social work have engaged with these topics and created this compact and content-rich practical handbook. It is aimed not only at professionals in social work and other interested parties but particularly at students of social work. The book provides a comprehensive overview and serves as an introduction to the subject. It covers fundamental mental illnesses, from alcohol dependence to depression and schizophrenia, addressing their origins, symptoms, diagnostic criteria, and possible treatment approaches.