Medication, Memory, and the Aging Brain: What Every Family Should Know

By Dr. Ranbir Dhillon, M.D.
Board-Certified Neurologist | Chief Health Advisor, HEALTHMAX

 

Many of my patients and their families are surprised to learn that some of the memory problems they are experiencing may not be caused by dementia at all — they may be caused by medications.

As we age, the way our bodies process medications changes. The liver and kidneys become less efficient at breaking down and clearing drugs. The brain becomes more sensitive to their effects. And very often, older adults are taking not just one medication, but many — a situation doctors call polypharmacy.

When multiple medications interact, the result can be confusion, memory loss, drowsiness, dizziness, and a host of cognitive symptoms that mimic dementia. In fact, studies suggest that a significant percentage of older adults diagnosed with "dementia" actually have reversible cognitive impairment caused by medication side effects.

The Science: How Medications Affect the Brain

Several classes of medications are known to have particularly significant effects on cognition.

1. Benzodiazepines

Medications like diazepam, lorazepam, alprazolam, and clonazepam are commonly prescribed for anxiety, insomnia, or agitation. They work by slowing down brain activity. But in older adults, their effects can linger far longer than intended, leading to grogginess, confusion, memory impairment, and an increased risk of falls. Long-term use of benzodiazepines has been specifically associated with an increased risk of developing Alzheimer's disease.

2. Anticholinergics

This is a large category of medications that block the action of acetylcholine, a neurotransmitter essential for memory and learning. They include many over-the-counter antihistamines, sleep aids, and bladder-control medications, as well as some antidepressants and muscle relaxants. A landmark 2019 study published in JAMA Internal Medicine followed nearly 300,000 older adults and found that those taking strong anticholinergic medications had a 49% increased risk of developing dementia over a ten-year period.

3. Opioids

Prescription painkillers can cause significant cognitive slowing, confusion, and sedation, especially in older adults. Even when taken as prescribed, these medications can impair memory and executive function.

4. Antipsychotics

These are sometimes prescribed to manage the behavioral symptoms of dementia, but they carry significant risks in older adults, including increased risk of stroke and death. They also cause sedation and cognitive blunting.

What the Data Tells Us

• A 2023 study in BMJ Open found that the use of anticholinergic medications was associated with more rapid cognitive decline in older adults.
• Research in JAMA Neurology found that long-term benzodiazepine use was associated with a significantly elevated risk of Alzheimer's disease.
• A 2024 study in The Journals of Gerontology found that reducing the number of unnecessary medications in older adults — a process called deprescribing — led to measurable improvements in cognitive function and quality of life.

What I Recommend to My Patients and Their Families

1. Keep an Up-to-Date Medication List

Write down every medication and supplement the person is taking — prescription, over-the-counter, herbal, everything. Include the dose and how often it is taken. Bring this list to every medical appointment. Many patients are surprised to learn just how many medications they are actually taking when they see it all written down.

2. Ask Questions Before Adding New Medications

Every time a new medication is prescribed, ask these questions: What is this for? How long should it be taken? Does it have cognitive side effects? Could it interact with other medications? Is there a non-drug alternative? Do not be afraid to ask. A good doctor will welcome these questions.

3. Discuss Deprescribing

If the person is taking multiple medications — especially in the categories I listed above — ask their doctor whether any of them can be reduced or stopped. Never stop a medication on your own; do it only under medical supervision. The goal is to eliminate medications that are no longer needed or that may be doing more harm than good.

4. Be Especially Cautious with Over-the-Counter Sleep Aids and Cold Remedies

Many of these products contain anticholinergic ingredients, and they are often taken without a doctor's knowledge. Before using any over-the-counter product, check the label and discuss it with the pharmacist or physician.

 

A Word to Caregivers

If you are caring for someone whose memory seems to be declining, do not assume it is only dementia. Medication side effects, dehydration, infection, thyroid problems, and depression can all contribute to cognitive impairment. A thorough medical evaluation — including a careful review of every medication — is essential.

And if you are taking medications yourself — perhaps to manage stress, insomnia, or chronic pain — please be aware of their potential cognitive effects. You need your memory and your mental clarity to care for someone else. Talk to your own doctor about your medications and whether safer alternatives exist.