The largest systematic review to date to address this issue suggests
no adverse effects of statins on cognition.
In 2012, the FDA issued a safety announcement, noting that statin use
might be associated with cognitive impairment such as memory loss or
confusion. To evaluate this association, researchers conducted a
systematic review and meta-analysis of 57 studies, including 19
randomized controlled trials, in which assessments of cognition among
statin users were reported; FDA postmarketing surveillance data also
Moderate-quality evidence suggested no excess risk for dementia or
mild cognitive impairment, and low-quality evidence suggested no
excess risk for Alzheimer disease. Analysis of postmarketing
surveillance data revealed similar cognitive-related adverse-event
reporting rates for statins (1.9 per million prescriptions) and two
cardiovascular drugs not associated with cognitive impairment:
losartan (1.6 per million prescriptions) and clopidogrel (1.9 per
Although this systematic review was limited by the small number of
randomized trials in which this outcome was evaluated, the data do not
suggest excess risk for cognitive impairment with statin use.
Nevertheless, a rare idiosyncratic effect of statins on cognition
remains possible for individual patients, even if studies of large
groups of people show no adverse effect on average. Indeed, in its
safety announcement, the FDA acknowledged that it drew substantially
from post-marketing case reports of adverse events.
Jamaluddin Moloo, MD, MPH reviewing Richardson K et al. Ann Intern Med
2013 Nov 19.