Mental health articles

Epidemiology of depression

Although there have been many attempts to examine the existence of depression in older people, accurate estimates of the prevalence of depression can be problematic due to the use of different instruments and the focus on different types of depression. Beekman et al. review of studies into the prevalence of depression in older people within the general population reports rates within the range of 2.9–15.9 per cent, with the lower rates for major depression and the higher rates for minor depression. Moreover, in a UK-based community survey by Lindesay et al.of approximately 1000 older people in an urban area, 4.3 per cent were identified as suffering from severe depression, with a further 13.5 per cent experiencing depression to a mild to moderate degree.

While there appears to be differences in the prevalence of different types of depression, there is an agreement that depression is the most common mental health problem experienced by older people.

Furthermore, depression in older people presents itself in a variety of different settings: •Banerjee found evidence of depression in 26 per cent of people receiving home care services from a local authority social services department. •Pitt  reported a prevalence rate of depression of 5–40 per cent in ‘geriatric’ inpatient populations.

•Ames  identified a figure of 40 per cent in a UK study of older people living in residential homes. •Koenig et al. report rates up to 45 per cent for older people in medical settings. •MacDonald identified the existence of depression in 31 per cent of all older people attending their GP. Within these and other studies, other important information about depression in later life has been identified. For instance, both Wragg and Jeste  and Teri and Wagner  have suggested that as many as 30 per cent of people with Alzheimer’s disease have a coexisting major depressive disorder. There also seems to be a strong association with loss events, poverty and social isolation, the coexistence of physical disease and recent bereavement  and depression being more common in women. Also, depression appears to have a poorer prognosis than in younger people with higher mortality rates, and high rates of persistence and recurrence. For example, Musetti et al. found that previous episodes of depression in older people were as high as 67 per cent. However, these findings may well have been influenced by inappropriate, or even non-existent, treatment and management regimens.

Unfortunately, many older people with depression, both severe and less severe, are often not diagnosed or not identified. This is of particular concern given the high risk of suicide that is found within the older population, an issue that we now consider in a little more detail.

Tags: depression, elderly, epidemiology