Recent research has shown that depression, anxiety disorders, and psychosis are more common than previously supposed in elderly populations without dementia. It is unclear whether the frequency of these disorders increases or decreases with age. Clinical expression of psychiatric disorders in old age may be different from that seen in younger age groups, with less and often milder symptoms. Concurrently, comorbidity between different psychiatric disorders is immense, as well as comorbidity with somatic disorders. Cognitive function is often decreased in people with depression, anxiety disorders, and psychosis, but whether these disorders are risk factors for dementia is unclear. Psychiatric disorders in the elderly are often related to cerebral neurodegeneration and cerebrovascular disease, although psychosocial risk factors are also important. Psychiatric disorders, common among the elderly, have consequences that include social deprivation, poor quality of life, cognitive decline, disability, increased risk for somatic disorders, suicide, and increased nonsuicidal mortality.Can J Psychiatry. 2011;56 (7):387-397.
Key Words: depression, anxiety, psychosis, elderly, epidemiologic methods, prevalence, risk factors, comorbidityM ost research on mental disorders have been concerned with dementia and to some extent with depression. Other mental disorders, such as anxiety disorders and psychotic disorders, have received less attention. This review will discuss the frequency of mental disorders in the elderly, and its relation to age. Aspects of mental disorders in the elderly without dementia, such as clinical expression and comorbidity, cognitive function and dementia, cerebral neurodegeneration and cerebrovascular disease, and risk factors and consequences, will also be discussed.
Frequency of Mental Disorders in the ElderlyThe prevalence of mental disorders is high among the elderly, 1-4 with a prevalence of almost 20% in people without dementia aged 65 years and older.2 While most people in epidemiologic studies are below age 90 years, it was recently reported that almost one-third of people without dementia aged 95 years fulfilled criteria for a psychiatric disorder: 17% had depression, 9% anxiety, and 7% a psychotic disorder.
5Most studies on the epidemiology of mental disorders in the elderly without dementia have been concerned with depression. Cross-sectional studies report prevalence figures of around 5% to 10% for depression, 3,[6][7][8][9][10][11][12] and 1% to 5% for major depression.2,3,13 These figures may be even higher in the developing world.14 This makes depression more common than dementia in people aged 65 years and older. The prevalence of depressive symptoms are even more common than the clinical diagnoses. Such subsyndromal forms of depression are nevertheless associated with adverse outcomes, such as stroke, disability, and mortality.
15-18Anxiety disorders include GAD, agoraphobia, panic anxiety disorder, OCD, social phobia, and specific phobias. Recent research suggests that anxiety disorder...