Note: This is sometimes also caused drug-induced delirium; although dementia and delirium are not really interchangeable terms, they're often used as though they are.

Definition:Elderly adults may exhibit the symptoms of dementia if they are taking too much of certain drugs. Benzodiazepines like Valium and Xanax are common culprits, as are strong analgesics, opiates, and narcotics. In extreme cases, these drugs may induce full-blown symptoms in previously healthy adults; they may also exacerbate the problems of patients who have already been diagnosed with some other form of dementia. Drug-induced dementia usually vanishes once the patient stops taking the drug.

Diagnosis: First (and obviously), the doctor should review the patient's current medications and search for possible culprits. Of course, if she's having memory problems, she may not be able to tell you (or she may confidently give you an inaccurate report), so it's a good idea to check medical records or speak with the patient's family. The time-course of the symptoms may also provide clues: did the patient suddenly get worse shortly after she started on a particular drug? Is she most lucid right before taking the drug (i.e., when its levels are lowest in the system)? Is she at her worst a short time after taking a dose? Did she seem better after she missed a dose?

Treatment: If possible, the patient should be slowly weaned off the drug. Unfortunately, if the drug is necessary to alleviate pain or treat an illness, then it may not be possible to remove the drug entirely. Sometimes it's possible to achieve a happy medium; other times, patients and their families must somehow choose between pain and dementia. Often, patients do not choose one or the other--rather, they choose to be lucid and in pain at some points and confused but pain-free at others. For example, one elderly woman avoids taking her pain medication when her relatives come to see her, thereby remaining lucid during their visit; once they leave, she takes her pain medication and quickly becomes confused.

In spite of these problems, the correct diagnosis of this iatrogenic illness is vital. Obviously, if a patient's dementia can be cured, the patient and her family will damn well want to know about it. Therefore, when examining a potentially demented patient, any competent neurologist or neuropsychologist will check for reversible causes of dementia before diagnosing probable Alzheimer's disease or multi-infarct dementia. In spite of this, many doctors overlook the possibility of drug-induced dementia or pseudodementia, meaning that a certain number of treatable adults end up languishing needlessly in nursing homes, causing patients and their families a tremendous amount of pain, anguish, and expense. Drug-induced dementia is rare--much rarer than Alzheimer's disease--but it's nonetheless a possibility well worth examining.