Studies have shown that medicines that alleviate psychological stress, such as selective reuptake inhibitors, olopatadine (a selective histamine H1 receptor antagonist), aprepitant (a selective neurokinin receptor one (NKR1) antagonist), and bupropion (an antidepressant that inhibits the reuptake of norepinephrine and dopamine), have also shown promising results in combating pruritus and improving AD; however, additional studies are needed to confirm their efficacy and safety [31,40,41,42,43]. This evidence concerns the gene HRH1 and Alzheimer disease.