ABSTRACT
It is difficult to differentiate between ‘normal’ and ‘abnormal’ behaviour. It also is difficult to provide a good pathophysiological description of psychiatric illnesses. For this reason it is difficult to make a correct psychiatric diagnosis. Without the correct diagnosis, it is not possible to establish the appropriate treatment. To overcome the diagnostic problem, different criteria have been used to diagnose mental illness and disorders. The diagnostic system used by most experts today is the DSM-IV (Diagnostic and Statistical Manual of Psychiatric Disorders, 4th revised edition). In this system, the diagnoses are criterion-based, i.e. a certain number of symptoms and conditions must be fulfilled before a diagnosis can be made. DSM-IV does not attempt to explain the causes of a condition. The system has proved to be useful regardless of whether one is seeking psychological, biological or social explanations for the illness.
