Using intranasal insulin, a different study by Appleby and Cummings found that people with Alzheimer's and Alzheimer's melancholy (aMCI) had better cognitive function, lower tau/a-beta 1-42 ratios, and less hypometabolism on brain fludeoxyglucose positron-emission tomography (PET) scans, which are symptoms of AD [10]. The gene discussed is MAPT; the disease is Alzheimer disease.