Many worries have already been aired. In mid-May an onslaught was delivered by the Division of Clinical Psychology of the British Psychology Society, which is sceptical about the very project of standardised diagnosis, especially of schizophrenia and bipolar disorders. More generally, it opposes the biomedical model of mental illness, to the exclusion of social conditions and life-course events. On a quite different score, Allen Frances, the chief editor of DSM-IV, has for years been blogging his criticisms of the modifications leading to DSM-5. More and more kinds of behaviour are now being filed as disorders, opening up vast fields of profit for drug companies. I shall discuss none of these important issues, and will try to be informative and even supportive until the very end of this piece, where I address a fundamental flaw in the enterprise.
Who needs the 947 pages of the DSM-5? All that most consumers need is the DSM-5 Diagnostic Criteria Mobile App. The more interesting question is who needs the DSM anyway? First of all, bureaucracies. Everyone in North America who hopes their health insurance will cover or at least defray the cost of treatment for their mental illness must first receive a diagnosis that fits the scheme and bears a numerical code. For example, opening the book at random, I find 308.3 for Acute Stress Disorder. The coding is required both by American private insurers and by Medicare. It is also required for the universal health insurance plans provided in Canadian provinces.
There is another quite different bureaucratic use. Why is this a ‘statistical’ manual? Because its classifications can be used for studying the prevalence of various types of illness. For that one requires a standardised classification. In a sense, the manual has its origins in 1844, when the American Psychiatric Association, in the year of its founding, produced a statistical classification of patients in asylums. It was soon incorporated into the decennial US census. During the First World War it was used for assessing army recruits, perhaps the first time it was put to diagnostic use.