Relationships among negative, positive, and depressive symptoms in schizophrenia and psychotic depression

Background. We examined relationships among positive, negative, and depressive symptoms in schizophrenia and major depression with psychosis. Method. Patients with schizophrenia (n = 17) and major depression and psychotic features (n = 25), with no prior psychopharmacologic treatment were assessed on scales measuring positive psychotic, negative, and depressive symptoms. Results. Analyses revealed that depressive symptoms positively correlated with anhedonia/asociality and avolition/apathy in both patient groups. Positive psychotic symptoms significantly correlated with depressive symptoms in the schizophrenic group. Conclusions. Several specific symptoms used in defining both depressive and negative syndrome constructs appear to be shared. The relationship between positive symptoms and depression in schizophrenia and not psychotic depression suggests the severity of depression may be involved in this relationship.