ANTIDEPRESSANTS AND COGNITIVE IMPAIRMENT IN THE ELDERLY

Cognitive impairment is an important consideration in the treatment of depression in the elderly because such impairment increases with age, is a symptom of depression, and is a side effect of many antidepressa nt drugs. Older depressed patients are more likely to suffer acute cog nitive impairment from medications' including antidepressants, often s uperimposed on the cognitive impairment of depression. Even mild cogni tive impairment can contribute to increased disability in the elderly. The occurrence of severe cognitive impairment (i.e., delirium) with t ricyclic antidepressants is probably related to anticholinergic effect s. Since the serotonin selective reuptake inhibitors (SSRIs) and some reversible inhibitors of monoamine oxidase (RIMAs) have little if any anticholinergic activity, these agents are expected to result in less cognitive impairment. This hypothesis is supported by a variety of com parative studies. The SSRIs and some RIMAs also have fewer additive ef fects with other psychoactive agents. Additional evidence suggests tha t some SSRIs and RIMAs may even improve cognitive functions through me chanisms separate from their antidepressant effects.