Depression in older adults with schizophrenia spectrum disorders: prevalence and associated factors

Although depression is common in older adults with schizophrenia, it has not been well studied. The authors examine those factors that are related to depression in a multiracial urban sample of older persons with schizophrenia.

The schizophrenia group consisted of 198 persons aged 55 or older who lived in the community and developed schizophrenia before age 45. Persons with substantial cognitive impairment were excluded from the study. A community comparison group (N = 113) was recruited using randomly selected census tract data. The authors adapted George's Social Antecedent Model of Depression, which consists of six categories comprising 16 independent variables, and used a dichotomous dependent variable based on a Center for Epidemiologic Studies Depression Scale cutoff score of > or = 16.

The schizophrenia group had significantly more persons with clinical depression than the community comparison group (32% versus 11%, respectively; chi(2) = 28.23, df = 1, p = 0.001). Bivariate analysis revealed that eight of the 16 variables were significantly related to clinical depression in the schizophrenia group. In logistic regression, six variables retained significance: physical illness (odds ratio [OR] = 1.60, 95% confidence interval [CI], 1.17-2.18), quality of life (OR = 0.84, 95% CI, 0.76-0.93), presence of positive symptoms (OR = 1.12, 95% CI, 1.02-1.21), proportion of confidants (OR = 0.03, 95% CI, 0.01-0.39), copes by using medications (OR = 2.12, 95% CI, 1.08-4.13), and copes with conflicts by keeping calm (OR = 1.34, 95% CI, 1.03-1.74).

Consistent with earlier studies of schizophrenia in older persons, the authors found physical health, positive symptoms, and several nonclinical variables to be associated with depression. Potential points for intervention include strengthening social supports, improving physical well-being, more aggressive treatment of positive symptoms, and increasing the recognition and treatment of depression.