Depression, psychomotor retardation, negative symptoms, and memory in schizophrenia

Objective: The purpose of this study was to examine the relations between d epression, psychomotor retardation, and negative symptoms in schizophrenia as well as the specific contribution of each of these factors to memory imp airment. Background: It has been suggested that depression overlaps with ne gative symptomatology in schizophrenia. The relation between psychomotor re tardation and negative symptomatology has been unclear. Method: The Hamilto n Depression Rating Scale, The Positive and Negative Symptom Scale for Schi zophrenia, and Scale for the Assessment of Negative Symptoms were used to a ssess depressive and negative symptomatology in a sample of patients with s chizophrenia. Verbal memory performance was assessed by a free recall test. Two indices of processing speed were measured. Correlations among variable s were computed. Results: Depression score was correlated with the avolitio n item from the Scale for the Assessment of Negative Symptoms and with both measures of processing speed. Negative symptomatology was unrelated to pro cessing speed. Memory performance was correlated with depression score, slo wing of processing speed, and avolition. Its correlation with depression sc ore and processing speed remained significant when the other factors were p artialled out. Conclusions: Memory performance in schizophrenia may be affe cted by lack of motivation, psychomotor retardation, and depression. It is suggested that negative symptoms could be split between a volitional compon ent linked to depression and cognitive efficiency and an emotional componen t unrelated to them.