A double-blind randomized, placebo-controlled clinical trial for older adults diagnosed with probable mild to moderate AD (n = 40) or amnestic mild cognitive impairment (MCI; n = 64) found that 4-months of twice daily intranasal insulin administration (20 IU total daily dosage) via a nasal drug delivery device improved delayed memory performance, preserved general cognition (measured by Alzheimer’s Disease’s Assessment Scale-cognitive subscale score) and preserved functional ability (assessed by the ‘activities of daily living scale’ from the Alzheimer’s Disease Cooperative Study) [76]. This evidence concerns the gene INS and early-onset autosomal dominant Alzheimer disease.