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Classification and Diagnosis of Mental Illness


Michael B. First

, MD, Columbia University

Last full review/revision Mar 2020| Content last modified Mar 2020

In 1980, the American Psychiatric Association published the third edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-III), marking the first attempt to approach the diagnosis of mental illness through standardized definitions and criteria. The latest edition, DSM-5, published in 2013, provides a classification system that attempts to separate mental illnesses into diagnostic categories based on descriptions of symptoms (that is, what people say and do as a reflection of how they think and feel) and on the course of the illness.

The International Classification of Disease, 10th Revision, (ICD-10), which was first published by the World Health Organization in 1992, uses diagnostic categories similar to those in the DSM-5. This similarity indicates that diagnoses of specific mental illnesses are becoming more standard and consistent throughout the world.

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