Schizoaffective psychoses: Genetical clues to classification

ArticleinAmerican Journal of Medical Genetics 60(1):7-11 · February 1995with27 Reads
DOI: 10.1002/ajmg.1320600103 · Source: PubMed
Abstract
The diagnostic classification of schizoaffective psychoses has varied much since Kasanin introduced the concept in 1933. The various classifications have agreed that schizoaffective psychoses present a combination of schizophreniform and affective symptoms, but the diagnostic criteria differ as to the number, quality, and time sequence of the symptoms even in recent classifications like RDC, DSM-III-R, and ICD-10. The classifications are syndromatical, and the etiology of the schizoaffective psychoses is still undetermined apart from evidence for a strong genetic factor. Results from family, twin, and adoption studies are divergent, but all the same, support a separate classification of broadly defined schizoaffective psychoses as possibly being phenotypical variations or expressions of genetic interforms between schizophrenia and affective psychoses.
    • "Family studies report that SAD occurs at a higher rate among relatives of probands with SCZ and MD. SCZ and MD occur at higher rates among relatives of probands with SAD, as compared to the general population (Bertelsen and Gottesman 1995; Kendler et al. 1993; Gershon et al. 1982). Research findings indicate that MD, SAD, and SCZ occur along a continuumfrom mood disorders to mood disorders accompanied by psychosis to schizophrenia. "
    [Show abstract] [Hide abstract] ABSTRACT: Schizoaffective disorder as a diagnostic entity is of particular present-day relevance; however, the concept of schizoaffective disorder, and its management and prognosis remain contentious. Descriptions of the disorder have varied over time. In this literature review, after tracking the evolution of the concept and nosology of schizoaffective disorder, research findings are summarized. This review takes a broad overview of the epidemiology, neurobiology, clinical presentation, diagnostic validity and stability, treatment, course, and outcome of schizoaffective disorder. Importance is given to the distinctness of schizoaffective disorder, and the overlap with schizophrenia and mood disorders, and problems associated with the construct are examined. Possible ways to treat the construct in the future in the best interest of patients, clinicians, and researchers are discussed.
    Full-text · Article · Jun 2015
    • "The two classes of symptom may occur simultaneously or at different times, although current diagnostic criteria require some temporal overlap, and affected patients tend to have an outcome intermediate between schizophrenia and bipolar disorder (for a review see McKenna, 2007 ). The nosological status of schizo-affective disorder remains a matter of controversy, with arguments that it represents a third independent form of psychosis (Procci, 1976), a form of bipolar disorder (Pope et al. 1980), a midpoint on a psychotic continuum (Crow, 1986), or the expression of genetic risk factors for both disorders (Bertelsen & Gottesman, 1995 ). One traditional method for resolving such uncertainties, family history studies, has not provided decisive support for any of these positions : first-degree relatives of schizo-affective patients have variously been found to show elevated rates of schizophrenia, affective disorder or both illnesses (Coryell & Zimmerman, 1988 ; Maier et al. 1993 ; Kendler et al. 1995 ; Laursen et al. 2005). "
    [Show abstract] [Hide abstract] ABSTRACT: BACKGROUND: Schizo-affective disorder has not been studied to any significant extent using functional imaging. The aim of this study was to examine patterns of brain activation and deactivation in patients meeting strict diagnostic criteria for the disorder.Method Thirty-two patients meeting Research Diagnostic Criteria (RDC) for schizo-affective disorder (16 schizomanic and 16 schizodepressive) and 32 matched healthy controls underwent functional magnetic resonance imaging (fMRI) during performance of the n-back task. Linear models were used to obtain maps of activations and deactivations in the groups. RESULTS: Controls showed activation in a network of frontal and other areas and also deactivation in the medial frontal cortex, the precuneus and the parietal cortex. Schizo-affective patients activated significantly less in prefrontal, parietal and temporal regions than the controls, and also showed failure of deactivation in the medial frontal cortex. When task performance was controlled for, the reduced activation in the dorsolateral prefrontal cortex (DLPFC) and the failure of deactivation of the medial frontal cortex remained significant. CONCLUSIONS: Schizo-affective disorder shows a similar pattern of reduced frontal activation to schizophrenia. The disorder is also characterized by failure of deactivation suggestive of default mode network dysfunction.
    Full-text · Article · May 2012
    • "independent disorders in their own right [Brockington and Meltzer, 1983; Kendell, 1988; Bertelsen and Gottesman, 1995; Kendler et al., 1995; Cheniaux et al., 2008; Craddock et al., 2009]. Criticisms include poor inter-rater reliability [Hiller et al., 1993; Maj et al., 2000] and instability of diagnosis over time [Schwartz et al., 2000; Laursen et al., 2005]. "
    [Show abstract] [Hide abstract] ABSTRACT: The nosological status of schizoaffective disorders remains controversial. Twin studies are potentially valuable for investigating relationships between schizoaffective-mania, schizoaffective-depression, and other psychotic syndromes, but no such study has yet been reported. We ascertained 224 probandwise twin pairs [106 monozygotic (MZ), 118 same-sex dizygotic (DZ)], where probands had psychotic or manic symptoms, from the Maudsley Twin Register in London (1948-1993). We investigated Research Diagnostic Criteria schizoaffective-mania, schizoaffective-depression, schizophrenia, mania and depressive psychosis primarily using a non-hierarchical classification, and additionally using hierarchical and data-derived classifications, and a classification featuring broad schizophrenic and manic syndromes without separate schizoaffective syndromes. We investigated inter-rater reliability and co-occurrence of syndromes within twin probands and twin pairs. The schizoaffective syndromes showed only moderate inter-rater reliability. There was general significant co-occurrence between syndromes within twin probands and MZ pairs, and a trend for schizoaffective-mania and mania to have the greatest co-occurrence. Schizoaffective syndromes in MZ probands were associated with relatively high risk of a psychotic syndrome occurring in their co-twins. The classification of broad schizophrenic and manic syndromes without separate schizoaffective syndromes showed improved inter-rater reliability, but high genetic and environmental correlations between the two broad syndromes. The results are consistent with regarding schizoaffective-mania as due to co-occurring elevated liability to schizophrenia, mania, and depression; and schizoaffective-depression as due to co-occurring elevated liability to schizophrenia and depression, but with less elevation of liability to mania. If in due course schizoaffective syndromes show satisfactory inter-rater reliability and some specific etiological factors they could alternatively be regarded as partly independent disorders.
    Article · Mar 2012
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