Epidemiologic Considerations in Studies of Cognitive Function in the Elderly: Methodology and Nondementing Acquired Dysfunction

Older persons are regarded as being at increased risk of adverse drug reactions because of altered drug metabolism, polypharmacy, the presence of multiple conditions, and noncompliance with prescribed regimens. Central nervous system adverse drug reactions are among the most commonly reported. Drug toxicity is regarded as one of the major "treatable" causes of dementia. The impact of cancer chemotherapeutic agents was noted above. Other drugs implicated include psychotropics, antihypertensive agents, and nonsteroidal antiinflammatory drugs. For example, Larson et al. defined cognitive impairment in terms of scores on mental status screening examinations, a test of psychometric intelligence, and a clinical memory battery. They found tricyclic antidepressants, sedative/hypnotics, and antihypertensive to be associated with increased odds of adverse reactions affecting cognitive performance. The relation between chronic alcohol abuse and gross cognitive dysfunction is well-established.