Psychologists, psychotherapists, psychiatrists and nurses are increasingly involved in treatments which include psychological therapy, and particularly cognitive therapy, for serious mental disorders. The aim of this book is to guide such professionals towards better practice by treating the the individual symptoms of delusions, voices and paranoia, rather than by the categorisation of schizophrenia. The authors provide an introduction to their cognitive model and show how therapy depends crucially on the collaborative relationship with the client. While earlier approaches to these distressing symptoms depended on an overall model of schizophrenia which emphasised fundamental discontinuities with normal thought and psychological processes, the authors' approach is supported by substantial research that indicates that delusions, voices and paranoia lie on a continuum of differences in thought and behaviour, and do not arise from fundamentally different psychological processes. This book offers a practical, research-based and essentially hopeful approach to the assessment and treatment of psychotic disorders and also an argument for the development of a person model for treatment, which is based on the person's enduring psychological vulnerabilities.