DBH and Anxiety: Three DA core genes were found to be significantly associated with at least one disorder: DRD2 is associated with OUD (p = 6.25E-08), SUD (p = 7.74E-13), anxiety (p = 3.10E-05), irritability (p = 3.41E-05) and neuroticism (p = 6.12E-13); DBH is associated with SUD (p = 3.20E-04); and DRD3 is associated with neuroticism (p = 3.38E-03) (Figure 2A; Supplementary Table S4).