Illnesses can be diagnosed through two main classification systems known as DSM and ICM. The DSM is the Diagnostic and Statistical Manual of Mental Disorders and is published by the American Psychiatric Association. It was first published in 1952 and has been followed by many further editions, with the latest published in 1994 (DSM-IV). Similarly, the ICM is the International Classification of Diseases and Related Health Problems and is published by the World Health Organisation. Mental disorders were included in the ICD for the first time in 1948 (ICM-6) and ICD-10 was published in 1992.
In the ICD there are 11 categories of mental disorders, such as mood disorders. The DSM assumes that all symptoms can be grouped together to form a specific mental disorder. It lists around 400 disorders including clinical depression. However, there are problems with these two classification systems. Diagnosis is the process of identifying a disease and allocating it to a category on the basis of symptoms and signs. Any system of classification will be of little value unless psychiatrists can agree with on another when trying to reach a diagnosis (Gelder et al) and so they can have inter-judge reliability. Another problem is that they are reductionist as they are based on medical/biological models, and they assume that illness can be identified by a set of specific symptoms. This can lead to mis-diagnosis if the symptoms are wrong.
Research into the effects of gender, ethnicity and social class also illustrate problems of reliability and validity in relation to the diagnosis of psychological abnormality. Accusations have been made by a number of people including Fernando (1991), Rack (1982) and Ussher (1992), that there are biases in diagnosis. There is relevant