A small number of users report memory lapses, though research is mixed and effects are usually reversible.

11. Corticosteroids

Long-term or high-dose use can affect mood, memory, and concentration.

12. Chemotherapy Drugs

Often referred to as “chemo brain,” these medications can cause temporary memory and attention problems.

13. Anticholinergic Drugs

This broad category blocks acetylcholine, directly interfering with memory and learning processes.

14. Parkinson’s Disease Medications

Some treatments can cause confusion or hallucinations, especially in older adults.

15. Anti-Nausea Medications

Certain drugs used for motion sickness or nausea can cause drowsiness and forgetfulness.

16. Urinary Incontinence Medications

Many of these drugs are anticholinergic and are strongly linked to cognitive decline in seniors.

17. Anti-Anxiety Medications (Non-Benzodiazepines)

Even milder anxiety treatments may cause brain fog when used long term.

18. Heart Rhythm Medications

Some antiarrhythmic drugs can reduce mental clarity as a side effect.

19. Diabetes Medications (Indirect Effect)

Low blood sugar caused by some treatments can lead to confusion and memory problems.

20. Over-the-Counter Sleep and Cold Remedies

Many contain hidden antihistamines that can quietly impair memory, especially when used frequently.

Why Older Adults Are at Higher Risk

As we age, the brain becomes more sensitive to medications. Slower metabolism and reduced kidney or liver function mean drugs stay in the body longer, increasing cognitive side effects. Taking multiple medications at once (polypharmacy) further raises the risk.