Deconstruyendo La Psicosis

Home / Research Background
Deconstructing Psychosis (February 15-17, 2006) 
Prepared by Michael B. First, M.D., DSM Consultant to the American Psychiatric Institute for Research and Education (APIRE), a subsidiary of the American Psychiatric Association

“Deconstructing Psychosis,” the fifth diagnosis-related research planning session convened under the conference series on the “Future ofPsychiatric Diagnosis: Refining the Research Agenda,” was held at APA headquarters in Arlington, Virginia on February 16th and 17th, 2006.  . APA’s American Psychiatric Institute for Research and Education (APIRE) is sponsoring the project in collaboration with the World Health Organization and the funding agency, the National Institutes of Health.  The five-year effort represents an unprecedentedscientific preparatory phase in advance of the next revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V) and other psychiatric classification systems.
Carol A. Tamminga, M.D., University of Texas Southwestern Medical Center in Dallas, TX, and Jim Van Os, M.D., Maastricht University, Maastricht, the Netherlands co-chaired the psychosis meeting.  Twenty-one invitedscientists from around the world participated.  The goal of the conference was to examine psychosis dimensionally,  the definition of, and new data concerning, schizophrenia, bipolar disorder, major depressive psychosis, and substance-induced psychosis.  "Functional" psychotic states (e.g. paranoia) and those related to defined pathological changes in the brain (e.g., dementia) were not a focus of thereviews or recommendations.

Three initial presentations reviewed the diagnostic features of schizophrenia, bipolar psychosis, and major depressive psychosis.  Jim Van Os, M.D. (Maastricht, the Netherlands) presented evidence for and against the diagnostic validity and usefulness of a schizophrenia diagnosis and discussed possible alternative approaches.  Noting that the current phenotype ofpsychosis originated in psychiatric hospitals at the time of Kraepelin, Van Os observed that little is known today about how psychosis presents in general practice settings or in the general population.  Given that psychosis results from the interaction of many genes, it is likely to be a continuous phenotype with mild forms present in the general population.  At present, 114 combinations of symptoms canlead to meeting the DSM-IV definition of schizophrenia; that, and the fact that different populations of patients are defined by different diagnostic systems (i.e., ICD-10, RDC, DSM-III-R, DSM-IV), raise questions about the validity of the DSM-IV definition.  One means of improving diagnosis will be to find groups that are more homogeneous, such as patients who are characterized primarily by thedeficit syndrome.  Another approach that Dr. Van Os proposed entails grouping symptoms into dimensions rather than people into categories, with the aim of developing quantitative phenotypes that correspond more closely to clinical realities than do the current diagnostic categories.   While some evidence suggests that a dimensional approach may be superior to a categorical approach in terms ofclinical usefulness and prognostic ability, additional research is needed to determine which type of dimensional representation would have the most diagnostic usefulness.  Commenting on Dr. Van Os’ paper, Wolfgang Gaebel, M.D. (Dusseldorf, Germany), noted that the diagnostic entity of schizophrenia comprises a loose boundary around a heterogeneous collection of interrelated and relatively distinctphenotypes.  These variants relate to relatively distinct brain-behavioral modules each with either overlapping or separate etiology, pathophysiology, course characteristics, and treatment response.  Dr. Gaebel suggested that the diagnostic concept of schizophrenia be abandoned or supplemented in favor of a modular illness concept that focuses on pathological functions and etiopathogensis (e.g.,...