Generalised anxiety disorder in elderly patients : epidemiology, diagnosis and treatment options

Abstract

Generalised anxiety disorder (GAD) is characterised by at least 6 months of excessive uncontrollable worry accompanied by symptoms of motor tension and vigilance and scanning. As with other anxiety disorders, GAD is less prevalent in older adults than younger adults. GAD has a high level of comorbidity with other psychiatric disorders and this has a bearing on estimates of its prevalence. GAD that is comorbid with another psychiatric disorder has a period prevalence of approximately 4% in community-dwelling older people. On the other hand, 'pure' GAD is less common, with a period prevalence of approximately 1%. Pure GAD in late life is a fairly even mix of chronic cases that began earlier in life and cases starting for the first time in later life. The most frequent and consistent finding regarding late-life generalised anxiety is its high level of comorbidity with major depression. There are few longitudinal data pertaining to the temporal association of generalised anxiety and major depression in late life, but the data that do exist suggest that the anxiety is frequently symptomatic of the depression. If generalised anxiety occurs exclusively during episodes of major depression, a separate diagnosis of GAD is not warranted. Cognitive behaviour therapy (CBT) is the most frequently studied psychological treatment for GAD. Although CBT is more effective than a wait-list control condition, it is not more effective than nondirective therapies in late-life GAD. Furthermore, a standard course of CBT appears to be less efficacious for GAD in older adults than younger adults. Further research is needed to develop more efficacious and specific forms of psychotherapy for late-life GAD. The three classes of medications that are most commonly used for GAD are: (i) antidepressants; (ii) benzodiazepines; and (iii) buspirone. Antidepressant medication is the pharmacological treatment of choice for most older adults with generalised anxiety. When generalised anxiety is secondary to an episode of major depression, the selection of an antidepressant is guided by the same principles that apply to treatment of nonanxious depression. Antidepressant medication is also effective for GAD in the absence of an episode of major depression. In this situation, citalopram and venlafaxine have been found to be efficacious in older people. Data from studies of mixed-aged patients suggest that escitalopram, paroxetine and trazodone may also be beneficial in late-life GAD. Despite their widespread use in older persons with anxiety, benzodiazepines have a limited role in the treatment of GAD in the elderly. If a benzodiazepine is initiated, pharmacokinetic considerations favour the use of either lorazepam or oxazepam. Buspirone also has a more limited role than antidepressants in the treatment of late-life GAD.