Depressive and negative symptoms in major psychiatric disorders.

Among 193 inpatients with Research Diagnostic Criteria (RDC) major psychiatric disorders, the scores in Hamilton's Rating Scale for Depression (HRSD) were higher among those patients with RDC schizoaffective disorder depressed type and major depressive disorder, whereas the scores in the Scale for Assessment of Negative Symptoms (SANS) were higher among patients with these two disorders, as well as those with RDC nonaffective psychoses (schizophrenia and unspecified functional psychosis). The HRSD and SANS items were factor-analyzed, yielding nine factors that discriminated depressive and negative symptoms. These findings suggest that although depressive and negative symptoms frequently coexist, they constitute discrete syndromes.