A multivariate exploration of basic symptoms.
Little is known about the relationship between the different categories of basic symptoms (BS). Researchers of the Bonn School have accurately described the progression from second-level BS (relatively characteristic BS) to first-rank Schneiderian symptoms. Using a multiple regression model, the present study tried to investigate which kind of dynamic deficiencies (DDs; uncharacteristic first-level BS) mostly lead to each type of second-level BS. A group of 108 patients with a DSM-III-R diagnosis of schizophrenia completed an inventory on BS, with all items in strict accordance with those of the Bonn Scale. Five dependent variables (cognitive thought disorders, cognitive perception disorders, cognitive action disorders, increased impressionability, cenesthesias) and four independent variables (DDs with direct negative symptoms, DDs with indirect negative symptoms, affective DDs, relational DDs) were considered. Among the significant findings, a widespread contribution of DDs with indirect negative symptoms to most of the dependent variables, and the special role of DDs with direct negative symptoms as a predictor of cognitive thought disorders, must be emphasized. Suggestions for further multivariate studies in the field of BS are presented.