Different electronic databases, including PubMed, Scopus, The Cochrane Library, ScienceDirect, and Google Scholar, were searched (till January 2025) by using specific keywords and MeSH Terms like Alzheimer’s disease, neuropsychiatric symptoms (stress, depression, anxiety, sleep disturbance, sleep disorder, obstructive sleep apnea, cognitive impairment, hypertension, hypothyroidism, and delusion), intervention, management, therapy, anti-psychotic drugs, memantine, omega 3, omega three, vitamin D, vitamin B12, cholinesterase inhibitors, ginkgo biloba, and caregivers. This evidence concerns the gene BCHE and Alzheimer disease.