The DSM-5 first draft has proposed many new diagnoses that would create enormous problems (especially false-positive "epidemics" and forensic misuse). Two perceived needs have driven the DSM-5 Work Groups in this unhappy direction:1) therapeutic zeal not to miss patients who might benefit from treatment; and 2) an aversion toward using the Not Otherwise Specified (NOS) categories. I will argue that these NOS categories impart a great deal of useful clinical information and are essential to the flexible and effective use of the manual. Giving every presentation a specific name and code in order to reduce the use of NOS would create much worse problems than it would solve.
The common prejudice against NOS diagnosis is that it puts psychiatry in a bad light. Why should as many as a third of our patients not qualify for anything more definitive? How do we explain this to them, their families, to referral sources, and to ourselves? How can we plan a specific treatment if the patient doesn't have a specific diagnosis? And so on. It may be useful to answer these questions in the act of exploring the different ways patients actually qualify for a NOS diagnosis:
1) There is simply not enough information to be more specific. Sometimes, this occurs because there was insufficient time for a complete evaluation or the patient is uncooperative and there is no informant or chart. Often, though, it comes from the inherent uncertainties of the situation. I have, for example, rarely felt comfortable with any label other than Psychotic Disorder NOS for psychotic teenagers who have only short track records. There is usually just too much uncertainty about the etiology (e.g., role of drugs) and their future course to be more definitive. There is nothing to be defensive about in using NOS in these situations. The designation Psychotic Disorder NOS conveys a great deal of information, while keeping tentative what deserves to be kept tentative. The immediate treatment target is clear without imposing a premature closure on long term treatment needs or prognosis. This can easily and productively be explained to patients and families.
2) The presentation clearly belongs in the section, but does not fit the prototype of any of the specific disorders defined there. For example, in DSM-IV we included binge eating disorder as an example of Eating Disorder NOS, rather than elevating it to a separate coded category. This allows the clinician the flexibility to diagnose an individual patient when this is deemed necessary without prematurely reifying a category that has yet to pass its risk-benefit test and might have unfortunate unintended consequences.
3) The condition is subthreshold to the specific criteria sets, but nonetheless causes obvious clinically significant distress or impairment. There is no bright line between mental disorder and normality. The decision whether a mental disorder is or is not present inherently has to be made on a case by case basis. The NOS categories provide needed flexibility in diagnosing the many people who present at the boundary with normality. Clinicians can use the appropriate NOS category for the early diagnosis of subthreshold conditions (e.g. "prepsychotic risk") when this clearly warranted for that particular person. This is far preferable to introducing a specific category for "psychosis risk" that would inevitably misidentify many individuals who would be much better off without diagnosis and treatment.
4) The condition presents a mixture of symptoms from different specific disorders that are individually subthreshold but jointly causative of clinically significant distress or impairment. The proposal for a Mixed Anxiety Depressive Disorder is a perfect example and is best handled as an NOS. If made an official category, it would immediately become one of the most popular diagnoses in DSM-5 without any proof that treatment would provide more good than harm for the millions of people who would get the diagnosis.
In all these ways, the NOS categories are indispensable. They should be celebrated, rather than denigrated, and used whenever they are the best description of the less than typical patient. The designation NOS is never really nonspecific or noninformative because it places the patient in a suitable section of the manual without providing more certainty or specificity than the situation allows.
Advice to DSM-5:
1) Accept the fact of life that a certain degree of diagnostic uncertainty and heterogeneity is inherent in the definition of mental disorder. Do not seek to attain an unattainable and pseudoprecise total specificity.
2) Appreciate that each NOS designation provides considerable information (for example, Psychotic Disorder NOS is very different in its treatment and prognostic connotations from Mood Disorder NOS or Eating Disorder NOS).
3) List the most common examples under each NOS category and allow these to be subtypes of that NOS (e.g., "Eating Disorder NOS, binge eating presentation" or "Mood Disorder NOS, premenstrual dysphoric presentation."
4) Clinicians using the NOS diagnoses are dealing with nonprototypical boundary cases. They must therefore be especially careful in determining that the presentation is accompanied by sufficient clinically significant distress or impairment to warrant a diagnosis of mental disorder.
5) Do not create new diagnoses in a vain attempt to replace NOS. The suggestions for new DSM-5 diagnoses should instead be available as examples under the most appropriate NOS ("minor neurognitive" under Cognitive Disorders NOS, etc). There are two exceptions among the proposed new diagnoses -- "paraphilic coercive" and "hypersexuality" -- both of which are harmful constructs whose use should be discouraged altogether, even within the NOS rubric.
The statistics have become astonishing, the stakes are typically massive, it is tough to talk about and even more difficult to do something about it. Technology, counselling, communication... they all compete with human nature. In addition to each and every situation is unique.