Premorbid functioning in schizophrenia: relation to baseline symptoms, treatment response, and medication side effects

Impaired premorbid functioning prior to the onset of acute psychosis has frequently been noted in schizophrenia. This study examined retrospectively the premorbid status of patients in their first episode of psychosis in order to determine relationships with baseline symptoms, treatment response, and medication side effects. One hundred eleven schizophrenic and schizoaffective patients participating in a large prospective study of first episode schizophrenia were evaluated with the Premorbid Adjustment Scale (PAS). Premorbid functioning in males became progressively worse over time. Deficit state patients exhibited worse premorbid functioning. A third of patients exhibited sustained poor premorbid functioning. At various developmental stages, lower "sociability and withdrawal" scores correlated with increased time to treatment response, more severe negative symptoms, increased drug-induced parkinsonism, and deterioration of premorbid functioning. Various mean PAS scores predicted susceptibility to tardive dyskinesia. Our findings suggest that prior to acute psychosis onset there are certain behavioral precursors reflected in premorbid functioning that may predict subsequent illness manifestations. Measures of premorbid functioning indicate that disease pathogenesis is manifest, albeit more subtly, prior to presentation of first psychotic symptoms.