Mood disorders in the elderly

Depression is a common illness in older people; major depression affects approximately 3%, and 10–15% have significant depressive symptoms that fall short of this diagnosis. Certain groups of people, such as the bereaved and those with dementia, are at especially high risk and need careful assessment for depression. Clinical features of late-life depression are broadly similar to those in younger adults. Neuro-imaging has shown atrophy of the hippocampus and key frontal and subcortical structures, and hyperintense lesions on MRI (especially white matter hyperintensities; WMH) occur with increased frequency, particularly in these brain structures. WMH also enlarge over time and their severity predicts the risk of future depression in older people. Neuropathological studies have demonstrated that these lesions are ischaemic; more widespread inflammatory changes may be present in the prefrontal cortex. This, and the strong bidirectional relationship of depression with vascular disease, supports the view that some older people have a ‘vascular depression’. Management of late-life depression is similar to that in younger adults, although older people may take longer to respond. Selective serotonin-reuptake inhibitors should be used as first-line treatment, and augmentation, especially with lithium, and ECT are efficacious in those who do not respond after switching to an alternative antidepressant. Continuation and maintenance treatment should be given with full-dose antidepressants; combination with manualized psychotherapy may be effective. Late-life depression is associated with increased mortality, and chronicity of the depression or of troubling symptoms occurs in about a third of patients, with a similar proportion having further depressive episodes.