Statin Use and Risk of Cognitive Decline in the ADNI Cohort.

•What is the primary question addressed by this study? The primary purpose of this study was to investigate associations between statin use and cognitive change, as well as diagnostic conversion, in individuals with cognitively normal (CN) status, mild cognitive impairment (MCI), and dementia due to Alzheimer disease (AD-dementia).•What is the main finding of this study? Statin use was not associated with longitudinal cognitive change in asymptomatic (cognitively normal [CN]) or symptomatic (late mild cognitive impairment [LMCI] or dementia due to Alzheimer disease [AD-dementia]) participants; however, there was an association between statin use and slower decline on a composite memory score in prodromal (early mild cognitive impairment [EMCI]) participants.Statin use was not associated with time to conversion to a more impaired diagnostic category for any diagnostic group (i.e., conversion to EMCI, LMCI, or AD dementia).•What is the meaning of the finding? In summary, these results support extant observational and randomized clinical trial findings that conclude statin use is not a risk factor for cognitive worsening (as indicated by the FDA black box warning) but that additional randomized trials in the prodromal EMCI stage may be warranted.