Why do the names of mental disorders keep changing every few years?
I am often asked this question specifically related to Asperger syndrome no longer being considered a diagnosis. I’ve been asked, “Did Asperger syndrome just disappear?” No, it did not disappear – it was just renamed and reclassified. Individuals who had a diagnosis of Asperger syndrome (or “Asperger’s”) would now be said to have a different disorder that is more in line with current research on developmental disorders. For example, they may now be said to have a mild, or high-functioning, version of Autism Spectrum Disorder or possibly a diagnosis of Social Communication Disorder.
First, some history on the nomenclature of mental illness. Some of the terms that historical medical and mental health professionals used to describe mental illnesses, and people with mental illnesses, are surprising and offensive to modern society. People with various psychological and developmental disorders were classified using terms like moron, feeble-minded, idiot, imbecile, hysterical, and lunatic. Now considered rude and offensive insults, these terms were once actual diagnoses. These terms are no longer used by professionals for two broad reasons:
The words morphed into insults and became degrading to use as diagnostic labels. Renaming a disorder whose name has become offensive in society is simply the right thing to do.
Research in mental health has redefined and reclassified symptoms and features into other disorders. For example, “idiot” was likely used to describe people we now know had one of a number of distinct disorders, such as Intellectual Disability, Autism Spectrum Disorder, genetic disorders such as Downs Syndrome, and the effects of a traumatic brain injury.
As you may already know, mental health and medical professionals use the Diagnostic and Statistical Manual of Mental Disorders, currently in its 5th Edition, to describe and classify mental disorders. Before the first DSM was ever written, however, the 1840 United States Census devised a single category for mental illness for the purpose of data collection. That category? “Idiocy/insanity.” The American Statistical Association protested this categorization, citing in part that African-American citizens were disproportionately coded as “insane.” Seven categories of mental illness were used for the 1880 census.
The American Psychiatric Association was formed in 1844, then called the wordy Association of Medical Superintendents of American Institutions for the Insane. By 1880, terms like dementia and epilepsy were being used, along with now-archaic labels such as melancholia. In 1917, a primitive classification manual was developed by the APA that included 22 diagnoses for use by mental hospitals to classify people with mental illness.
Fast forward to 1952, and the first edition of the DSM was published by the American Psychiatric Association. It included 106 named mental disorders. The DSM-II came along in 1968 and included 182 disorders. The increase in named disorders was not because more people were mentally ill, but scientists and health care professionals split broader categories into more specific collections of symptoms and revised criteria based on research. Revisions of the manual have also been aimed at increasing the reliability of diagnosis among mental health professionals and standardizing diagnosis with other countries. Notably, the sixth printing of the DSM in 1974, still known as the DSM-II, removed homosexuality as a mental illness based on research demonstrating that homosexuality is not a mental disorder.
The DSM-III was published in 1980 to further improve standardized diagnostic practices and to incorporate the findings of new research discoveries. The DSM-III-R, published in 1987, included 292 diagnoses, and the DSM-IV (1994) listed 410 disorders. The DSM-IV-TR (2000) was a text revision of the manual that did not change the diagnostic categories. The DSM-5 was published in 2013 and included extensive revisions to diagnoses based on research and the work of a large task force of mental health professionals. Like its predecessors, the DSM-5 also changed some labels to better align with socially acceptable language (e.g. “Mental retardation” is now listed as “Intellectual disability”).
The DSM is not a cookbook by which anyone can look up their symptoms and diagnose themselves; diagnosing a mental disorder involves far more than checking off symptoms. No matter how convinced you are that you meet all of the diagnostic criteria for a certain mental disorder, only a licensed mental health professional can make that determination. Diagnosing a mental disorder involves not only identifying the presence of symptoms, but determining the presence of “clinically significant distress or impairment” and ruling out other possible explanations for the symptoms.
The DSM is, simply stated, a taxonomy of mental disorders. Just like the terms “homo sapiens” and “arachnid” are helpful in categorizing animals, the names we apply to mental disorders are made-up terms aimed at making sense of the broad range of emotional, cognitive, and behavioral symptoms in mental health. While the DSM does include information about the prevalence and possible causes of the disorders it lists, that is not its purpose, and it does not include information on treating the disorders. The DSM’s current purpose is to provide a common language for professionals to use in the study and diagnosis of mental disorders. Each revision aims to improve the identification of mental disorders and, by extension, improve access to treatment.
The DSM-5 will certainly be revised again and again, as research into human psychology and behavior is ongoing. I look forward to the coming advances in the field of mental health.