The purpose of this study was to examine association between both smoking initiation (SI) and progression to ND by young adulthood and (a) history of neuroticism during adolescence, (b) DRD4 7R+, and (c) interaction between neuroticism and DRD4 7R+.
The dopamine receptor D4 (DRD4) and catechol-O-methyltransferase (COMT) genes have been implicated in neuroticism-related traits and approach-related temperaments which are supposed to be associated with disgust sensitivity.
Thus, the present study suggested the association between the short allele of the DRD4 exon III polymorphism and personality trait of Neuroticism in Japanese subjects.
Both molecular genetic factors (the D2 dopamine receptor (DRD2) and the D4 dopamine receptor (DRD4) polymorphisms) and environmental influences of living in an alcoholic or nonalcoholic home on the personality traits of Extraversion and Neuroticism were assessed in drug-naive, young adolescent boys.
The strongest effects occurred in those infants with the s/s 5-HTTLPR polymorphism who also were lacking long D4DR alleles which in some studies has been linked to adult novelty seeking.1,6 These infants showed most negative emotionality and most distress to daily situations, temperament traits that are perhaps the underpinning of adult neuroticism.
The behavioral effects of two common polymorphisms linked respectively in some, but not all, studies to novelty seeking (dopamine D4 receptor-D4DR) and neuroticism and harm avoidance (serotonin transporter promoter region-STPR) were examined in a group of 81 two-week-old neonates.