DOI link for Categorical classification
Categorical classification book
The frustrating lack of progress in psychiatric research and treatment may be partly due to the limitations of the dominant classification systems generally used in psychiatry: the Diagnostic and Statistical Manual of Mental Disorders (published by the American Psychiatric Association) and the International Statistical Classification of Diseases and Related Health Problems (ICD published by the World Health Organization). The ICD is an initiative of the World Health Organization (WHO), first published in 1948 and it is not restricted to mental disorders. Mental disorders are listed under chapter 5. A categorical system classifies a disorder as being present or not, depending on whether the patient fulfills a certain set of criteria (Chmura Kraemer et al., 2004) and is designed to make communication between researchers and clinicians worldwide simple and efficient (Sheehan et al., 1998).