Prevalence of Mental Disorders in the Elderly: The Australian National Mental Health and Well-Being Survey

Abstract

To describe the 1- and 12-month prevalence of mental disorders, their demographic correlates, and their impact on service utilization and disability in individuals 65 years of age and over in a comprehensive epidemiological survey of mental health in Australia. A noninstitutionalized national probability sample of elderly Australian residents was interviewed as part of the Australian National Mental Health and Well-being Survey (NMHWS). The prevalence of International Classification of Diseases, Tenth Revision and Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition mental disorders was estimated from the Composite International Diagnostic Interview and other screening instruments. Of 1,792 elderly NMHWS respondents, 13% reported symptoms consistent with a mental disorder in the past 1 month, and 16% reported symptoms consistent with a mental disorder in the past 12 months. Women experienced higher rates of affective disorders and generalized anxiety disorder and had lower rates of substance abuse compared with men. After excluding cognitive disorder, increasing age was associated with less likelihood of having symptoms of any mental disorder. Older age and never having been married were associated with less likelihood of having symptoms of an affective disorder. Those with cognitive impairment were more likely to have had symptoms consistent with an affective disorder. Comorbidity was predictive of increasing disability on the 12-item Short Form but rates of mental health consultation were low, even for those with multiple disorders. Community-dwelling elderly Australians experience substantial rates of mental disorders. Demographic correlates of mental disorder in this elderly population appear to differ from those established in younger populations. Mental disorder in elderly Australians is associated with significant disability, but rates of specialist mental health consultation is low, even for those with multiple comorbidities. The reasons for this must be examined.