Pharmacologic treatment of depression in the elderly.

Depressive illness is the most common emotional disorder in those of advanced age, occurring in approximately one seventh of those over 65 years old. Despite its high prevalence, depression in the elderly is more complicated to diagnose and treat than depression in younger adults. Successful pharmacotherapy for depression in the elderly requires careful consideration of the pharmacodynamics and pharmacokinetics of antidepressant medications of various classes to balance the therapeutic effects and side effect profiles of these agents. The heterocyclic antidepressants are effective in the elderly, but their use in this population may be limited by anticholinergic and/or cardiovascular side effects. The monoamine oxidase inhibitors also are effective, but compliance problems limit their usefulness in older persons. The serotonin selective reuptake inhibitors have been shown to be effective in the elderly, and their side effect profiles are generally milder than those of the older agents. Elderly patients receiving psychotropic drug therapy must be monitored carefully because treatment failure due to undermedication and drug toxicity due to overmedication may have more severe consequences in older than in younger adults.