Longitudinal assessment of negative symptoms in schizophrenia/schizoaffective patients, other psychotic patients, and depressed patients

This study assessed differences in negative symptom presentation between sc hizophrenia/schizoaffective, other psychotic, and depressed patients over a 10-year followup period. One hundred fifty individuals with schizophrenia or schizoaffective disorders (SZ/SZAF), other psychotic disorders (OP), and depressed patients (DP) were assessed at index hospitalization, then reass essed at 4.5-year, 7.5-year, and 10-year followups. SZ/SZAF patients signif icantly differed from DP patients in frequency and persistence of negative symptoms but were not significantly different from the OP group. Negative s ymptoms were not associated with depression in any diagnostic group. Dosage , but not simple use, of conventional antipsychotic medications was related to severity of symptoms in the SZ/SZAF group. Although negative symptoms w ere typically most severe and most common in the SZ/SZAF subjects in compar ison to the DP patients, there were few statistically significant differenc es in the phenomenology of negative symptoms between the OP and SZ/SZAF gro ups. The data are consistent with a model that identifies negative symptoms as common to mental illnesses generally, with particularly high rates in p sychotic illnesses.