The Older Brain on Drugs: Substances That May Cause Cognitive Impairment

Jenny Rogers, MD, Psychiatry Department, Postgraduate Education, University of British Columbia, Vancouver, BC.
Bonnie S. Wiese, MD, Psychiatry Department, Postgraduate Education, University of British Columbia, Vancouver, BC.
Kiran Rabheru, MD, CCFP, FRCP, Clinical Associate professor, Psychiatry Department, University of British Columbia, Vancouver, BC.

Alcohol, recreational drugs, over-the-counter, and prescription medications may cause a range of cognitive impairments from confusion to delirium, and may even mimic dementia. Moderate to high alcohol consumption is one of the often overlooked risk factors for development of dementia and cognitive impairment among older adults. Substances such as opioids, benzodiazepines, and anticholinergics pose a particular risk of cognitive impaiment and the risk increases when these are combined with multiple medications, as polypharmacy is common in patients over 65. A substance-induced dementia may have a better prognosis compared to other types of dementia, as once the instigating factor is gone, the cognition often improves.
Key words: Alcohol related dementia, geriatric substance abuse and dependence, polypharmacy, anticholinergic adverse effects, cognitive impairment.