Participants with at least one copy of allele A (Met), along with specific alleles (L/S; 10/12; T/C; and 3/3) of other possible MDD-related genes (5HTTLPR, 5HTTVNTR, HTR2A, and APOE), had an increased risk of developing depression (p = 0.004; OR = 5.99; 95%CI = 1.66‐21.56) [25]. This evidence concerns the gene APOE and major depressive disorder.