The term cognition-enhancing medications is misleading

The subheading “Cognition-enhancing medications” in the article by Lee and colleagues is misleading.¹ Drugs for treating dementia do not enhance cognition; at best, they have minimal effects on cognition or marginally slow the decline in cognitive function.

A Cochrane review of memantine looked at the evidence in 3 different groups of patients with dementia. In those with moderate to severe Alzheimer disease there was a small beneficial effect on cognition at 6 months (2.97 points on the 100-point Severe Impairment Battery). In mild to moderate Alzheimer disease, the effect on cognition was barely clinically detectable, and for mild to moderate vascular dementia the effect on cognition was not supported by clinical global measures.² After 26 weeks of treatment, rivastigmine only slowed the rate of cognitive decline; it did not enhance cognition.³ Donepezil versus placebo led to a 2- to 3-point mean difference in score on the Alzheimer’s Disease Assessment Scale 70-point cognitive subscale. Galantamine at a dose of 16 to 24 mg/d improved the score by about 3.4 points but led to more withdrawals due to adverse effects and caused cholinergic adverse effects in up to 20% of patients.⁴

The independent French drug bulletin Prescrire International concluded that, “at best, drugs for Alzheimer’s disease can only stabilize or slightly improve cognitive function, in only a minority of patients,”⁵ reflecting the change in rating of medical benefit for these drugs by the French Pharmacoeconomic Committee from “major” to “low.”⁶

In support of their recommendations for the use of “cognition-enhancing medications” the authors cite an article in the Canadian Geriatrics Society Journal of CME.⁷ The lead author of that paper was Dr Lee, who was also the lead author of the paper in Canadian Family Physician.¹ In her earlier article, Dr Lee acknowledged receiving educational grants or honoraria from Pfizer, Janssen-Ortho, Novartis, AstraZeneca, and Solvay. The other 3 authors of that article also listed conflicts with various companies that make drugs to treat dementia.⁷ In the recent article, Dr Lee did not list any conflicts of interest.¹

Ahn et al looked at the association between the presence of individual principal investigators’ financial ties to the manufacturer of the study drug in randomized controlled trials and the trial’s outcomes after accounting for the source of research funding.⁸ They concluded that the financial ties of principal investigators were independently associated with positive clinical trial results. Whether the same conclusion applies to authors of narrative review articles was not investigated.

Misleading titles and subheadings might influence the way readers interpret the material that follows and should be avoided.

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