The Genetics of Delusional Psychoses

Abstract

In a genetic study of the first-degree relatives of 77 patients with delusional (paranoid) psychoses, the morbidity risks for schizophrenia, affective disorders, and atypical psychoses were evaluated using ICD-9 criteria. The prevalence of schizophrenia was 3.10 percent (4.12 percent with age correction to 40 years and 4.94 percent with age correction to age 60), which is higher than in investigations of paranoid psychoses, but lower than in studies of paranoid schizophrenia. The prevalence figure for affective disorders (age-corrected 3.04 percent for unipolar plus bipolar patients) is also intermediate to those for relatives of paranoid schizophrenics and paranoid psychotics. When the 77 index delusional patients were subdivided into axial syndromes (endogenomorphic-schizophrenic, endogenomorphic-cyclothymic, and organomorphic axial syndromes), two very homogeneous subgroups emerged. The endogenomorphic-schizophrenic subgroup showed high rates of schizophrenic secondary cases, whereas the endogenomorphic-cyclothymic subgroup showed high rates of affectively disordered secondary cases. The third organomorphic subgroup showed a high prevalence of atypical psychoses among first-degree relatives. Thirty-seven of the 77 index patients could not be assigned to any axial syndrome; their first-degree relatives had an increased prevalence of schizophrenia, but affective disorders were no more frequent than in the normal population. These data suggest that the heterogeneous group of paranoid psychoses can be meaningfully subdivided by use of axial syndromes which are viewed as representing "basic" disturbances underlying delusional symptomatology.

Delusional Psychoses: Genetic Findings as a Critical Variable for the Validation of Diagnostic Criteria

“…Further information was gathered form hospital charts and interviews with other relatives or doctors. Some data of this study have already been published [Schanda et al, 1983]; the main shortcoming of this publication was the non blind diagnosis of the first-degree relatives. This shortcoming was now removed by blind rediagnosis with several diagnostic criteria.…”

“…The diagnostic systems under study were the Re search Diagnostic Criteria (RDC) [Spitzer et al, 1978] and the Vienna Research Criteria (VRC) in the version of Schanda et al [1983], Because of the resulting small samples after division into subgroups, we are presenting only the raw data (prevalence) in the tables. If, for better com parison with other studies, age-corrected morbidity risks are mentioned in the text, these were calculated using Weinberg's abridged method [Schulz, 1936] (age of risk schizophrenia 15-40, for MDI 15-60).…”

Position of Affective Symptomatology in the Course of Delusional Psychoses

“…Spitzer et al. 1978] and Vienna Research Cri teria (VRC) in a modified form according to Schanda et al [1983]; doing so. at the initial period, he was blind to subsequent course.…”

Conceptualization of Schizophrenia: The Symptom-Oriented Approach

“…Thus diagnostic systems which allow the attribution to schizophrenia on the basis of psychotic symptoms alone may entail the danger to group disorders of divergent origins under this heading. This objection, corroborated by several studies o f our group [16][17][18][19], concerns, for instance, the symptomatological schizophrenia criterion of D SM -IV [20], which allows two psychotic symptoms to determine the diagnostic attribution. Like other operational classifications D SM -IV tries to counterbalance this risk with the help of additional course-or severity-related criteria.…”