Drugs can wreak havoc on your memory and overall mental performance.

This recognition leads some people to disavow prescription drugs altogether – even when they’re helpful. Case in point: even if the anticonvulsant topimirate has nasty cognitive side effects 1 if you’re a manic-depressive or epileptic the benefits may outweigh the downsides.


The worst offenders, cognitively speaking, are anticholinergics and benzodiazepines. Examples of anticholinergic drugs include tricyclic antidepressants and over-the-counter allergy medications like Benedryl.

Anticholinergic drugs so profoundly block memory consolidation that they’re the tool of choice to simulate dementia in animals. See: the scopolamine model of dementia.


Benzobuddies is a great resource for those interested in benzodiazepine discontinuation. Benzodiazepines globally suppresses neural activity which impairs long-term potentiation. However, excess neural activation is also bad for the brain. That’s why it’s possible that in some situations benzodiazepines may have a net-positive effect on cognition. See: An emerging paradox: benzodiazepines rescue deficits in transgenic Alzheimer’s mice by improving slow wave sleep (SWS) coherence.

Statins (Surprisingly)

Statins (e.g., Lipitor) have a generally good safety profile. They have historically been prescribed like they’re vitamin C.

But statins are not without side effects, which rarely can be serious. You might be surprised to learn that statins can have a pronounced effect on memory.

At the UCSD, Dr. Golomb documented 171 cases where patients reported cognitive problems while taking statins. In 9/10 cases, discontinuing the drug resolved the symptoms. She concludes that:

Evidence from RCTs and studies of other designs indicates existence of additional statin-associated adverse effects (AEs), such as cognitive loss, neuropathy, pancreatic and hepatic dysfunction, and sexual dysfunction. Physician awareness of statin AEs is reportedly low even for the AEs most widely reported by patients.

The following drugs can impair memory function. If you’re taking any of these medications, your doctor can substitute in an alternative that’s less hard on the central nervous system. For example, instead of using Benedryl as a sleep aid, you could take hydroxylamine, rozerem or suvorexant. Or instead of using topimirate as a mood stabilizer, you could try lamotrigine, which is a cleaner drug.

  1. Sommer BR, Mitchell EL, Wroolie TE. Topiramate: Effects on cognition in patients with epilepsy, migraine headache and obesity. Ther Adv Neurol Disord. 2013;6(4):211-27.
Drug Class Citations
Zolpidem (Ambien) Z-drug Shih HI, Lin CC, Tu YF, et al. An increased risk of reversible dementia may occur after zolpidem derivative use in the elderly population: a population-based case-control study. Medicine (Baltimore). 2015;94(17):e809. [ref]
Amitryptaline (Elavil)
Desipramine (Norpramin)
Imipramine (Tofranil)
Nortriptyline (Pamelor)
Venlafaxine (Effexor)
Tricyclic Antidepressant Podewils LJ, Lyketsos CG. Tricyclic antidepressants and cognitive decline. Psychosomatics. 2002;43(1):31-5. [ref]
Atorvastatin (Lipitor)
Ezetimibe/simvastatin (Vytorin)
Fluvastatin (Lescol)
Lovastatin (Menacer)
Pravastatin (Pravachol)
Rosuvastatin (crestor)
Simvastatin (Zocor)
Statins Kelley BJ, Glasser S. Cognitive effects of statin medications. CNS Drugs. 2014;28(5):411-9. [ref]
Venlafaxine (Effexor) SNRI [ref]
Alprazolam (Xanax)
Clonazepam (Klonopin)
Diazepam (Valium)
Lorazepam (Ativan)
Oxazepam (Serax)
Temazepam (Restoril)
Triazolam (Halcion)
Benzodiazepines Barker MJ, Greenwood KM, Jackson M, Crowe SF. Cognitive effects of long-term benzodiazepine use: a meta-analysis. CNS Drugs. 2004;18(1):37-48. [ref]
Brompheniramine (Dimetapp)
Clemastine (Tavist)
Antihistamines [ref]
Diphenhydramine (Benadryl)
Doxylamine (Unisom, NyQuil)
Antihistamine Han L, Agostini JV, Allore HG. Cumulative anticholinergic exposure is associated with poor memory and executive function in older men. J Am Geriatr Soc. 2008;56(12):2203-10. [ref]