SAN ANTONIO – Older adults with schizophrenia are more likely to be depressed if they have a lower quality of life index, are less religious, and take more medications or receive more psychotherapy than do other adults with schizophrenia, reported investigators at the annual meeting of the American Association for Geriatric Psychiatry.
But evidence also suggests that the outlook for older people with schizophrenia is not as bleak as was once thought, said Dr. Carl I. Cohen, professor and director of the division of geriatric psychiatry at State University of New York, Brooklyn, and SUNY Downstate Medical Center.
Dr. Carl I. Cohen
"We now recognize that outcome in schizophrenia is much more heterogeneous than we originally conceived," Dr. Cohen said.
Among older adults with schizophrenia, the prevalence of depression (including mild or subsyndromal depression) ranges from about 44% to 75%, but little is known about the prognosis of depression in this group, he said.
Dr. Cohen reported data from a longitudinal follow-up study of 101 people aged 55 and older with schizophrenia. The mixed-race sample consists of men and women with schizophrenia who were living in New York City and available for structured interviews at baseline (median age, 59) and at a median follow-up of 52 months. In all, 65% of those in the sample were living in supported residences, and 35% were living independently.
The investigators defined depression as a CES-D (Center for Epidemiologic Studies–Depression) scale score of 16 or greater, subsyndromal or mild depression as a score of 8-15, and no depression as a score lower than 8.
Of the 29 people in the sample with syndromal depression at baseline, the researchers found that 12 (41%) remained depressed at follow-up, 10 (35%) had subsyndromal depression, and 7 (24%) had remission of depression.
Of the 31 people with subsyndromal depression at baseline, 9 (29%) went on to more serious depression, 10 (39%) still had mild depression, and 12 (32%) were no longer depressed at follow-up. Of the remaining 41 patients with no depression baseline, 3 (7%) went on to develop syndromal depression, and 7 (17%) developed the subsyndromal form; 31 (76%) remained free of depression.
The investigators also found that suicidality seemed to moderate over time, with 80% (12 of 15) patients who tested positive for suicidality at baseline no longer wishing to die or having suicidal thoughts or actions at follow-up. In contrast, of those with no evidence of suicidality at the outset, only 7 of 86 (8%) went on to develop suicidality.
When the investigators looked for predictors of depression at the second interview in a bivariate analysis, they found "surprisingly few" predictors, Dr. Cohen said. Depression at follow-up was not predicted by demographics, physical health, instrumental activities of daily living, cognitive functioning, social network variables, lifetime traumatic events, coping styles, or PANSS (Positive and Negative Syndrome Scale) scores.
Only a lower quality of life index, less religiosity, receipt of more medication and/or psychotherapy, and baseline depression were predictive of depression at follow-up.
In logistic regression analysis that was controlled for age, sex, number of confidants, physical disorders, and other factors, the only significant predictors for depression at follow-up were religiosity (odds ratio, 0.84; P = .03), CES-D score greater than 7 (OR, 7.27; P = .002), and receipt of mental health services at follow-up (OR, 1.40; P = .04).
The findings suggest that clinicians need to develop strategies for diminishing depression among older adults with schizophrenia, possibly through pharmacotherapy, cognitive-behavioral therapy that focuses on depressive and psychotic symptoms, and – for some patients – the encouragement of religiosity, Dr. Cohen said.
The study was funded by grants from the National Institute of General Medical Sciences. Dr. Cohen had no conflict of interest disclosures.