Common medications may be linked to memory decline

Older adults who used medicines with anticholinergic effects were more likely to develop mild cognitive impairment in a study that tracked thinking ability over time. The association appeared stronger in people who also carried genetic or biological markers associated with Alzheimer’s disease.

The results point to medication review as an important clinical and research issue. However, they do not prove that any one drug directly caused memory loss, or that stopping a medicine will necessarily prevent decline.

Anticholinergic effects work by blocking acetylcholine, a chemical messenger used by the nervous system. Some drugs in this category have a stronger effect than others, and the total burden can become important when a person takes several of them.

Researchers examined 688 adults, with an average age of about 74, who started the study with normal thinking and memory. Participants reported their regular medication use and then completed repeated cognitive tests during follow-up that lasted as long as ten years.

Published in Neurology, the study found that people taking at least one anticholinergic medication had a 47% higher relative risk of developing mild cognitive impairment. The analysis adjusted for several measured factors, including depression, medication count and cardiac history.

Mild cognitive impairment refers to a decline in memory or thinking beyond what would normally be expected with aging, while day-to-day independence is often largely maintained. It can have multiple causes and does not always lead to dementia.

Researchers are also looking at tests that may help identify Alzheimer’s risk before symptoms begin.

The team also reviewed markers tied to Alzheimer’s disease. In the study, people who used these medicines and had additional risk markers showed stronger links to cognitive decline than comparison participants without those combined factors.

Those subgroup findings should be interpreted cautiously. The people being compared differed in more than medication use, so the larger risk estimates cannot be blamed on a drug alone.

The study depended on self-reported medication exposure and did not randomly assign treatments. The health conditions that led people to take these medicines may also have played a role in later cognitive problems.

Another limitation is that medications and doses can change over time. A research classification may not fully reflect what reaches the brain or how any individual responds.

The practical takeaway is to review the full medication list with a clinician or pharmacist, including over-the-counter sleep and allergy products. When appropriate, they can discuss alternatives with a lower anticholinergic burden while weighing why each medicine is being used.

Any changes should be planned, not made suddenly. Larger studies that test structured medication reduction could help show whether lowering anticholinergic burden really preserves thinking skills and which patients are most likely to benefit.

If you are interested in this topic, please read articles about Is It Dementia or Just Aging Understanding Memory Loss, and Hidden Stress May Quietly Cause Memory Loss in Older People.

For more information, please see articles about Gut Inflammation Could Speed up Memory Loss Study Finds, and Fitness Games Could Help Slow Memory Loss in Early Dementia.

Source: University of California San Diego.