Comparison of negative symptoms in schizophrenic and poor outcome bipolar patients

Using the Scale for the Assessment of Negative Symptoms (SANS), affective blunting, alogia, and attentional impairment were assessed in 30 manic patients with chronic impairment of inter-episode instrumental functioning and 85 chronic schizophrenic patients. The schizophrenic patients had markedly higher ratings on all three negative symptom dimensions. When negative symptoms were examined categorically, no manic patient was rated to show prominent affective flattening or alogia. This relative specificity may not apply to attentional impairment which was rated as prominent in 17% of the manic patients and in 55% of the schizophrenic patients.