Neuropsychiatric effects of drugs in the elderly.

Since the elderly consume large numbers of drugs, drug-induced disease must be high on the list as a suspected cause of changes in behavior. Neuropsychiatric side effects of drugs in the elderly are not rare events. While proceeding to investigate medical, neurological, and psychiatric causes of a change in the cognitive status or behavior in an elderly patient, it is important to consider a possible psychotoxic drug as an offender or co-offender. Failing to do so may lead to inappropriate testing and further unnecessary and possibly deleterious therapeutic measures. In the case of dementia, the worst treatment would be institutionalization before identifying a drug as the cause of the cognitive dysfunction.