Treatment of GAD(Generalized Anxiety Disorder) in the Elderly

Treatment of GAD in the Elderly

Epidemiological data suggests that GAD is highly prevalent in the geriatric population (prevalence rates ranging from 0.7 to 7.1%), accounting for the majority of anxiety disorder cases in this group. GAD is the most common of the pervasive late-life anxiety disorders. In the elderly, anxiety symptoms are often associated with depression, medical conditions and cognitive dysfunction. Thus, a careful differential diagnosis to eliminate exogenous causes of anxiety and identification of other coexist-ing conditions is necessary. For example, treatment of medical illness, depression, or underlying dementia may reduce anxiety symptoms. Dose reductions or elimination of anxiety-inducing medications as well as reducing stressful life circumstances may also reduce anxiety symptoms. However, if these interventions are not effective in reducing anxiety, pharmacotherapy may be necessary. Several factors influencing pharmacologic treatment in the elderly should be considered. These factors include altera-tions in pharmacokinetics and pharmacodynamics of psycho-tropic drugs, primarily because of reduced hepatic clearing ef-ficiency, alterations in the response of the central nervous system to drugs, such as changes in receptor sensitivity, and concurrent medical conditions that may alter drug effect, side-effect profile, and toxicity.

Benzodiazepines can be effective in the treatment of anxi-ety symptoms. However, older patients are often sensitive to their effects. Adverse effects may include increased sedation, tendency to fall, psychomotor discoordination and cognitive impairment. Older patients may become disinhibited by benzodiazepines and experience agitation and aggression. The administration of long-acting benzodiazepines such as diazepam and chlorazepate may result in increased accumulation of the drug predisposing the patient to these side effects. Conversely, the use of short half-life high potency benzodiazepines such as alprazolam may be associated with more severe withdrawal symptoms following rapid discontinuation. Because of these factors, benzodiazepines should be prescribed for the briefest period of time, at the lowest therapeutic dose, giving preference for the short half-life, low-potency benzodiazepines such as oxazepam. We recommend initiating treatment with oxazepam at low doses (10 mg t.i.d.), to be increased gradually, while carefully monitoring for the emer-gence of side effects.

Buspirone has been extensively used in the treatment of GAD symptoms. The lack of associated sedation, discoordina-tion and dependence with the use of buspirone makes its use in the elderly less problematic. However, additional research is needed to determine its long-term efficacy in the GAD elderly population. The average therapeutic doses of buspirone for eld-erly patients range from 5 to 20 mg/day.

The use of TCAs in the anxious elderly patient should be viewed in light of the side-effect profile of TCAs. Side ef-fects commonly associated with the use of TCAs, such as the anticholinergic effects and orthostatic hypotension, may be es-pecially troublesome in these patients. We therefore recommend the use of TCAs with low anticholinergic and hypotensive effects such as desipramine and nortryptiline, starting at low doses (10 mg/day) that are raised slowly and gradually.

Finally, despite the widespread use of the newer antidepres-sant agents, specifically the SSRIs and the SNRIs, in the treatment of adult GAD patients, very limited data exist regarding their use in the anxious elderly population. However, preliminary evidence suggests that they can decrease symptoms, improve quality of life and potentially promote healthier outcomes in geriatric patients who have comorbid anxiety and depression and/or comorbid mental and physical illness. A potential drawback of venlafaxine in this population is the need to monitor for drug-induced blood pressure elevation in those taking the medication.

Most controlled studies examining CBT in older adults have focused on the treatment of GAD. This literature suggests that CBT is effective in the treatment of GAD in this population. For example, group-administered CBT was found to be effec-tive in reducing GAD and coexistent symptoms in older adults. In conclusion, several agents may play an important role in the treatment of anxiety in the elderly. However, until more studies in the elderly GAD population are available, treatment choices should be guided by clinical judgment and specific factors rel-evant to this patient population, such as medical comorbidity and age-associated changes in the drug metabolism.