Comorbidity with depression in older people: the Islington Study

The coexistence of depression with other psychiatric disorders, which has been extensively studied in younger adults, has hardly been reported in older people. This study focuses primarily on comorbidity and other associations of depression in a community sample of older adults. A random sample of 700 older people in the inner London borough of Islington, and any other adults living with them, were interviewed at home using standardized instruments. Older people who were depressed were likely to have other comorbid physical and psychiatric pathology, namely general anxiety, phobic anxiety, physical disability, somatic symptoms, sleep disturbance and subjective memory impairment. The overwhelming majority of older people with depression were not receiving pharmacological treatment. Such lack of treatment may be because patients with physical or psychiatric comorbidity have presenting symptoms that obscure the diagnosis of depression. We conclude that while the majority of elderly people are psychiatrically well and do not require day to day help, those who are depressed have a significant rate of comorbidity. Health workers treating elderly people with depression should look for other physical and psychiatric conditions routinely. Comorbid depression should be considered in elderly people with subjective memory loss, sleep disturbance, somatic complaints, anxiety disorders or activities of daily living (ADL) limitation.