The deficit syndrome of the psychotic illness. A clinical and nosological study.

The deficit syndrome is thought to be specific to and a subtype of schizophrenia; however, there are scarce or no data on the prevalence and characteristics of this syndrome in non-schizophrenic psychoses. The aim of this study was to explore the prevalence and correlates of different types of negative symptoms (NegS) in a mixed sample of psychotic disorders. Six-hundred and sixty psychotic inpatients were classified according to the presence and type of NegS into the following groups: no NegS, transitory NegS, persistent secondary NeS, persistent doubtful secondary NegS, and persistent primary NegS (i. e., deficit symptoms). Furthermore, the nosological status of this symptom classification such as its clinical and etiological correlates were examined. Depending on the diagnostic criteria used for diagnosing schizophrenia, the prevalence of the deficit syndrome in schizophrenia and in non-schizophrenic psychoses ranged from 14%-32% and 2%-22%, respectively. Deficit syndromes in both schizophrenic and non-schizophrenic patients shared most of the syndrome-related clinical features. Regarding the associated clinical pattern, the transitory NegS group was closer to the group without NegS than to the groups with enduring NegS. Patient groups with enduring primary and enduring secondary NegS did not show relevant clinical or etiological differences, thus, suggesting that the primary versus secondary issue may be less relevant than previously acknowledged. The deficit syndrome may be diagnosed irrespective of the specific categories of psychotic disorders.