Minor depression in the aged. Concepts, prevalence and optimal management

Research evidence indicates that depressive symptoms, or subsyndromal cases of minor or mild depression are very common in the elderly population. However, the nosological status of minor depression is poorly and variable defined, with no current consensus. DSM-IV has, however, introduced a research category of minor depression for future validation and discussion, involving a smaller number of depressive symptoms to obtain a diagnosis than is required for major depression. The elderly population are particularly prone to subsyndromal depression because of their increased tendency to alexithymia (the inability of patients to verbalize or fantasize affective experience) and somatisation, which masks their depression. Furthermore, minor depression is not a stable entity and can predict the development of major depression as well as characterise its sequelae when major depression is in partial remission. Most studies have suggested that minor depression is roughly twice as common as major depression, with an increase in frequency in residential or medical inpatients compared with community-dwelling elderly people. Most studies also confirm the notion that minor depression increases in frequency with age in a curvilinear fashion; there is an increase in symptoms in people aged in their 30s, a decrease in middle age, a steady increase in old age and a very steep increase in people aged greater than 80 years. This effect may be attributable to the concomitant increase in physical morbidity in old age, which is closely associated with minor depression. The exact relationship between cause and effect of comorbid physical illnesses is unclear, but the association is strong for a number of common medical disorders. Impairment of well-being and functional disability is marked in minor depression. There are no available data on the relative risk of suicide in minor depression. Treatment remains unclear, but in the absence of evidence to the contrary, antidepressant medication and psychotherapeutic interventions, alone or combined, are currently the recommended course of action.