The authors note that postmarketing surveillance reports, observational studies, and some small randomised trials of statin therapy have suggested statins, or the low levels of LDL cholesterol that result from their use, may be associated with impaired cognitive function. However systematic reviews and meta-analyses have not shown consistent evidence of adverse effects of statins on cognition, and the Statin Cognitive Safety Task Force in 2014 concluded that statins are not associated with these adverse effects.
There is some evidence that PCSK9 inhibitors are associated with cognitive adverse events; however incidence is low and with broad confidence intervals around the observed hazard ratios. The purpose of the current study was to prospectively assess cognitive function using a validated instrument - the Cambridge Neuropsychological Test Automated Battery.
Longer-term data on cognition from an extension of the FOURIER trial will be available in due course; the authors comment that even longer-term data are desirable (for these and other lipid-lowering agents) as patients may be on such treatments for decades.