Beyond DSM-5: Levels of explanation in psychiatry (the “fuzzy set” approach)

Daniel Lende of Neuroanthropology has listed a lot of interesting reading re the DSM-5 process that basically boils down to whether this discussion and debate should be open to the public.

I think it should, and not only because psychiatry intersects with powerful market forces (i.e., the global psychopharmaceutical industry – UPDATE: See Kalman Applbaum’s terrific coverage of the Texas vs. Johnson & Johnson Risperdal trial at Somatosphere.net) and the use of the DSM extends well beyond psychiatry (neuroscience researchers, schools, the legal system, how we define disability) but also because the DSM “suffuses the ways in which patients (and the broader public) make sense of their distress and dysfunction” (Gone & Kirmayer, 2010). Greg Downey in a January 2011 post, makes a great point about the consequences of diagnosis:

What Desjarlais’ account [from Shelter Blues: Sanity and Selfhood Among the Homeless] suggests is that being diagnosed as insane or schizophrenic or some other medical condition can, through a process that is as much sociological and economic as it is medical, lead a person to become homeless.  In the process, the day-to-day reality of the individual becomes increasingly slippery, increasingly challenging — for a mentally ill individual, this transition might make recovery virtually impossible as they are shorn of all the material supports of normal personhood and pushed into an alternative reality that would severely test the healthiest among us.

But I also think a tremendous amount of care and thought has gone into the DSM-5 process on the part of individual work groups. For example, William Carpenter and Jim van Os (both members of the psychosis work group) provide a thoughtful commentary on the pros and cons of recognizing an attenuated psychosis syndrome in adolescents and young adults at high risk for schizophrenia and other psychotic disorders in the American Journal of Psychiatry, which opens with the following excerpts:

The best hope for secondary prevention of the often devastating course of psychotic disorders resides in early detection and intervention when individuals first develop symptoms. There is sufficient evidence for attenuated psychosis syndrome as a clinical syndrome with predictive validity to establish this diagnostic class. There is much that clinicians can and should do for care-seeking individuals with distress and dysfunction who manifest early psychotic-like psychopathology. A new DSM-5 diagnosis can focus attention on this syndrome and stimulate the creative acquisition of new knowledge that may be life altering for afflicted persons. There is little reason to rely on less specific diagnostic categories, such as anxiety and depression, if we can reli- ably give patients and their families a more informative picture of their situation.—William T. Carpenter

The best hope for early intervention in psychotic disorders resides in public health measures for the population as a whole rather than in attempts to diagnose risk in individuals for what will be a low incidence of future psychosis. Making services more accessible, providing general diagnostic training to primary care workers, and creating community awareness will make the filters on the pathway to mental health treatment more permeable for people with early psychotic symptoms in need of care. Individual treatment should be initiated early but when it is indicated, as when cri- teria are first met for psychotic disorder not otherwise specified. Creating a diagnostic class that does not unambiguously define a specific group, treatment, or outcome does not add value for patients and their families.—Jim van Os

DSM-6.0 and Beyond

The DSM-5 system of classifying mental disorders may be the last of its kind. (Is there anything else particularly ground-breaking about the DSM-5, apart from the possibility of including a “person-centered” dimensional approach in the case of personality disorders, which would involve “a reduction in the number of specified types” as well as an interesting DSM-II-ish description of specified types (or prototypes) “in narrative format that combines typical deficits in self and interpersonal functioning and particular trait configurations”?)

On the other hand, Kenneth Kendler has a review in the latest issue of Molecular Psychiatry (“Levels of explanation in psychiatric and substance use disorders: Implications for the development of an etiologically based nosology”) that argues for an understanding of disorder “in terms of “fuzzy sets of cross-level mechanisms varyingly instantiated in individual patients.”

Such a viewpoint has been developed to explain what kinds of things biological species are – fuzzy sets defined by mechanisms at multiple levels that act and interact to produce the key features of the kind [Boyd, 1999].

(Actually, Boyd uses a phrase, “‘homeostatically’ sustained clustering of properties or relations,” that has a nice, systems-oriented ring to it.) This seems like a good direction for DSM-6.0 and beyond.  The next ten years may reveal an even more radical rethinking of all sorts of boundaries that will create deeper understandings of brain and mind in social, cultural, and physical contexts in terms of complex systems that have the potential of underwriting more collective and powerful responses to our “problems of living.”

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