Diagnostic and Statistical Manual of Mental Disorders-IV

The fourth edition of the Diagnostic and Statistical Manual of Mental Disorders, DSM-IV published by the American Psychiatric Association (APA) in 1994, acts as a comprehensive guide to the nomenclature, classification, and diagnostic criteria for mental disorders in the United States. Used widely for research, clinical, and statistical purposes, the DSM-IV provides a systematic method to form psychiatric diagnoses and facilitates communication by providing general and universally used definitions and descriptions of mental disorders, and possible courses of action for each diagnosis.

The lack of an adequate statistical measure of mental illness in U.S. censuses in the nineteenth century sparked the formation of a systematic nomenclature system for mental illness in 1917. This new system, developed by the APA and the National Commission on Mental Hygiene, was devised mainly for clinical and statistical use. The APA developed the first edition of the DSM (DSM-I) in 1952 after mental illnesses were included in the World Health Organization's sixth edition of the International Classification of Diseases (ICD-6). Sixteen years later, DSM-II appeared, with few changes. In 1978 DSM-III—including more specific diagnostic criteria, a multiaxial system, and unbiased descriptions—helped the efforts of clinicians and researchers. The revised edition (DSM-III-R) was published in 1987. DSM-IV is notably more culture sensitive than DSM-III-R.

DSM-IV uses five axes to diagnose mental illness. Each axis considers a different component of a patient's overall physical and mental health. The axial system allows clinicians and researchers to better gauge how a mental illness fits with a patient's overall health and lifestyle. Axis I consists of current mental disorders; some of the disorders classified on Axis I are learning disorders, dementias, schizophrenias, and mood, anxiety, eating, and sleep disorders. Personality disorders (e.g., obsessive-compulsive personality disorder) in adults and developmental problems (e.g., mental retardation) in children and adolescents are listed on Axis II. General medical conditions that may influence mental health are listed on Axis III. Axis IV rates an individual's psychosocial stressors, and Axis V rates an individual's level of functioning on a numerical scale (Davison and Neale).

The DSM-IV uses a categorical classification approach for assigning diagnosis, which has the advantage of simplicity and ease of communication (Widiger). However, categorical classification of psychopathology is exceedingly difficult; a psychological diagnosis is rarely defined by the presence of a single attribute. It is more typical for diagnosis instead to be based on some of several listed attributes (e.g., symptoms, course), none of which alone is sufficient for diagnosis.

In addition, the majority of psychological phenomena operate on some type of continuous distribution that categorical systems cannot precisely and reliably describe (Frances). Categorical systems also are less able to account for borderline cases and variability across clinical settings according to variables such as geographical location, socioeconomic status, and coexisting medical conditions (Finn).

Mental disorders that commonly affect older adults are generally found in the "Delirium, Dementia, Amnestic, and Other Cognitive Disorders" or the "Mental Disorders Due to General Medical Condition" sections of DSM-IV. However, a number of the diagnostic criteria for other disorders, most notably anxiety disorders, are still based primarily on studies in adolescents and younger adults and are applied primarily to these age groups.