Text book of Psychopathology has been prepared with the aim to provide an understanding of abnormal behaviour scientifically and compassionately. The general sequence of the book may be summarised as follows: Chapter one presents a brief historical discussion that traces the changing approaches to mental disorders from ancient to modern times. Chapter two begins by defining the concept of psychopathology or abnormal behaviour, its characteristics, differences between normal and abnormal behaviour and includes a description of mental health professionals. Chapter three is related to assessment techniques and classification systems of abnormal behaviour. Chapter four deals with biological, psychosocial and sociocultural causal factors of abnormal behaviour. Chapter five, six and seven explain nature, types, causes, symptoms and treatments of anxiety disorders, somatoform and mood disorders and substance related disorders. Chapter eight reflecting the nature, types, causes and treatment of personality disorders has been included to provide an understanding of psychopaths. A detail description of schizophrenia, a complex and dangerous disorder, also has been presented in chapter nine which includes nature, types, symptoms, causes and treatments of this disorder. Various forms of clinical interventions or psychotherapy has been presented in chapter ten. And finally, chapter eleven deals with the concept,components and importance of mental health, characteristics of mentally healthy people, factors influencing mental health and measures for promoting mental health.