Section 7. Mental Health Disorders

Chapter 98. Overview of Mental Health Care

Topics: Introduction | Mental Illness in Society | Classification and Diagnosis of Mental Illness | Treatment of Mental Illness

Classification and Diagnosis of Mental Illness

In 1952, the American Psychiatric Association first published the Diagnostic and Statistical Manual of Mental Disorders (DSM-I), marking the first attempt to approach the diagnosis of mental illness through standardized definitions and criteria. The latest edition, DSM-IV, published in 1994, 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, Clinical Modification (ICD-10-CM), a book published by the World Health Organization, uses diagnostic categories similar to those in the DSM-IV. This similarity suggests that diagnoses of specific mental illnesses are becoming more standard and consistent throughout the world.

Advances have been made in diagnostic methods. Several brain imaging techniques are available, including computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET), a type of scan that measures blood flow to specific areas of the brain (see Section 6, Chapter 77). These imaging techniques are being used to map brain structure and function in people with normal and abnormal behavior, giving scientists greater understanding of how the brain functions in people with and without mental illness. Research that has differentiated one mental health disorder from another has led to greater precision in diagnosis.