SCHIZOPHRENIA AND AFFECTIVE-DISORDER - DISTINCT ENTITIES OR CONTINUUM- AN ANALYSIS BASED ON A PROSPECTIVE 6-YEAR FOLLOW-UP

The purpose of this study was to determine whether the preponderance o f data support a continuum hypothesis of the psychoses or a concept of separate, autonomous illnesses. Patients (N = 70) were hospitalized f or nonmanic psychoses, given structured interviews and a dexamethasone suppression test (DST), and diagnosed according to the Research Diagn ostic Criteria (RDC). Patients were then evaluated at 1 year and 6 yea rs with a structured interview. Diagnoses were made at three points of time: intake, 1 year. and 6 years. The patients were divided into gro ups that had a consistent (over the three points) set of affective dis order diagnoses (affective disorder or schizoaffective disorder, mainl y affective [AD group]) and those that had a consistent set of schizop hrenic diagnoses (schizophrenic or schizoaffective disorder, mainly sc hizophrenic [S group]). A third group (inconsistently diagnosed) consi sted of subjects who at one point were diagnosed in the AD group and a t another in the S group. A series of discriminant function analyses s uggested that the AD group differs widely from the S group; and the in consistently diagnosed group most closely resembled the AD group. The family background of the inconsistent group was similar to that of the AD group. The DST and outcome showed that the inconsistent group was more like the AD group than the S group. Using the characteristics of the medical model-clinical picture, outcome, laboratory tests, and fam ily history-the group that was inconsistent with regard to diagnosis o ver time appeared similar to the AD group. Taking the follow-up evalua tion into account, the data favor the possibility that patients who ha ve a variable clinical diagnosis over time do not suffer from schizoph renia. Copyright (C) 1996 by W.B. Saunders Company