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-TR, published in 2022, 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, 11th Revision, (ICD-11), which was first published by the World Health Organization in 2019, uses diagnostic categories similar to those in the DSM-5-TR. This similarity indicates that diagnoses of specific mental illnesses are becoming more standard and consistent throughout the world.
