APP and Alzheimer disease: In 2021 a systematic metanalysis in investigating NAD + , its derivatives, and their association with cognitive function restricted to the AD context revealed that NAD+ improves learning and memory.374 Subsequent studies concurred, showing cognitive benefits in a range of rodent AD models including APP/PS1-mutant mice,373,375 and intracerebroventricular injection of Aβ1–42.376