Psychiatry is a very important subject in today’s world. Almost every second person is falling prey to mental ailments due to the excessive stress and competition in our daily life. The mounting complexities and the diversified responsibilities mandates us to possess knowledge and awareness of the various types of mental health ailments and their causes. This text has been written keeping in mind the requirement of not only nurses but also a common man to know and understand the various types of psychiatric ailments, their causes, assessment and cure. It is a ready reckoner for nurses and all others dealing with mental health problems and patients.