This textbook presents a critical overview of the main theoretical perspectives relevant to mental health practice and argues that no one theory provides a comprehensive framework for practice. By examining traditional models of mental health, as well as new, it challenges some of the accepted views in the field and illustrates the importance of recognising the contribution, strengths and limitations of the range of different ideas. With new chapters on intersectional and environmental perspectives as well as an expanded focus on LGBTQIA+ and trauma-informed models, this new edition has been updated throughout to reflect contemporary issues and new research. Part of the Foundations Of Mental Health Practice series, this is indispensable reading for anyone studying or working in mental health.