COMT and Abnormal emotional state: Personality traits were included as an effect of GxE studies in only 6.6% of the papers (n = 21/315), with studies focusing mainly on 5HTTLPR [10/162 papers (6.2%), including impulsivity, neuroticism, emotional dysregulation, and self-esteem], DRD4 (n = 1, impulsivity), BDNF (n = 1), NPSR (n = 1, anxiety sensitivity), TPH1/TPH2 (n = 2, harm avoidance and impulsivity), COMT (3/17 impulsivity), and 5HTR (n = 2).