Familiality of symptom dimensions in schizophrenia

The division of schizophrenic symptoms into three core dimensions - psychom otor poverty, reality distortion, and disorganisation - is well established . When factor analytic studies have included affective symptoms they have i dentified two additional dimensions - manic and depressive. Whether these f ive dimensions represent underlying psychopathology of a genetic or environ mental aetiology remains unclear. The aims of this study were to perform fa ctor analysis of symptoms in a group of familial schizophrenic patients and to investigate the familiality of the symptom dimensions identified, and t heir relationship to clinical characteristics. Symptoms were recorded, usin g the Operational Criteria Checklist for Psychotic Illness, for 155 Caucasi an subjects with an RDC diagnosis of schizophrenia, schizoaffective disorde r, or psychosis of unknown origin, from 61 families multiply affected with schizophrenia. Factor analysis indicated five symptom dimensions: depressiv e, manic, reality distortion, disorganisation, and psychomotor poverty. The psychomotor poverty, disorganisation, and manic dimensions were shown to h e familial. Psychomotor poverty, disorganisation, and reality distortion we re all associated with deterioration from premorbid functioning and chronic course of the disorder. In addition, psychomotor poverty was significantly related to poor premorbid functioning, as well as to single marital status and unemployment at onset. Disorganisation was significantly related to si ngle marital status and unemployment at onset. The familiality of the psych omotor poverty, disorganisation, and manic dimensions supports their use in the delineation of homogeneous subsets for genetic studies. (C) 2001 Elsev ier Science B.V. All rights reserved.