Depression during the longitudinal course of schizophrenia.

This prospective research investigated the occurrence and persistence of depression during the longitudinal course of schizophrenia. The research goals were to (1) compare depression in schizophrenia with that in schizoaffective and major depressive disorders, (2) assess whether some schizophrenia patients are vulnerable to depression, and (3) assess the relationship of depression to posthospital adjustment in schizophrenia. A total of 70 schizophrenia, 31 schizoaffective depressed, 17 psychotic unipolar major depressed, and 69 nonpsychotic unipolar major depressed patients were assessed during hospitalization and prospectively assessed for depression, psychosis, and posthospital functioning at 4.5- and 7.5-year followups. A large number (30% to 40%) of schizophrenia patients evidenced full depressive syndromes at each followup, including a subgroup of patients who evidenced repeated depression. Even when considering the influence of psychosis on outcome, depression in schizophrenia was associated with poor overall outcome, work impairment, lower activity, dissatisfaction, and suicidal tendencies. During the post-acute phase assessed, neither the rates nor the severity of depressive syndromes differentiated depression in schizophrenia from schizodepressive or major depressive disorders. However, the depressed schizophrenia patients showed poorer posthospital adjustment in terms of less employment, more rehospitalizations, and more psychosis than the patients with primary major depression. The high prevalence of depression in schizophrenia warrants its incorporation into theory about the disorder. A continuum of vulnerability to depression contributes to the heterogeneity of schizophrenia, with some schizophrenia patients being prone to depression even years after the acute phase. Depression in schizophrenia is one factor, in addition to psychosis, associated with poor outcome and requires specific attention to the treatment strategies by psychiatrists.