The prevalence of psychiatric disorders and subsyndromal mental illness in low-income, medically ill elderly

Objective: This study estimated the past and current prevalence of psychiatric illness and subsyndromal mental illness (both pre-relapse and new onset) in a sample of low-income, medically ill older adults. Method: A convenience sample of 95 public sector medical patients aged 55 and older were assessed for the presence of psychiatric diagnosis and symptoms using the Geriatric Depression Scale, Beck Anxiety Inventory, the Short Michigan Alcohol Screening Test, and the Computerized Diagnostic Interview Schedule (DIS-C). Results: Dysthymia and Major Depression were the most prevalent current disorders and Alcohol Dependence the most prevalent past disorder. Overall, 25 percent met criteria for at least one Axis I disorder. An additional 44 percent of patients had subsyndromal mental illness: 14 percent had subsyndromal depression, 17 percent were significantly anxious, and 30 percent were problem drinkers. A prior model predicting current Axis I disorder in younger people was found to be predictive of current Axis I but did not predict to subsyndromal disorder. Conclusions: The rates of psychiatric disorders and symptoms in this older, low-income population were similar to those in other samples of older medical patients. The findings from this research suggest the need for larger epidemiological studies of the prevalence of psychiatric disorders in this disadvantaged aging population. The complexities of this type of research are also discussed.