Negative symptoms in the course of first-episode affective psychosis.

To determine whether the prognostic implications of negative symptoms apply to functional psychotic disorders other than schizophrenia, we investigated the significance of negative symptoms in the 18-month course of individuals experiencing a first episode of affective psychosis. Although negative symptoms were found to occur during the acute phase of a major depression or a bipolar disorder with psychotic features, they did not endure and had limited prognostic value. Further, the findings suggest that enduring negative symptoms may be specific to schizophrenia.