2010). The aim of the present study was to examine the existence of a nonadditive/epistatic interaction between two functional polymorphisms COMT Val158Met and DAT1 3′UTR VNTR in a large cohort of healthy Caucasian subjects. Especially, we wanted to explore potential associations between

risk alleles/genotypes of Inhibitors,research,lifescience,medical both genetic polymorphisms for NEM as measured by the Affective Neuroscience Personality Scales (ANPS) questionnaire. The ANPS was chosen for this study because, unlike personality questionnaires derived from a lexical approach, this scale has been constructed to reflect most directly emotional neuronal circuits of the mammalian brain (Davis et Inhibitors,research,lifescience,medical al. 2003). We hypothesized that the association of DAT1 with NEM is dependent on genetic variation of the COMT gene because the Met allele of COMT has been previously associated with NEM and the Val/Val genotype with PEM. DA variation should influence vulnerability to negative emotions, possibly due to changes in DA availability. We hypothesized that carriers of the 9R/9R and Val/Val genotype configuration would show lowest scores on NEM, as this website assessed by the ANPS scales Sadness, Anger, and Fear. Material and Methods Participants A total of 1041 healthy Inhibitors,research,lifescience,medical Caucasians of German origin filled

in a paper-and-pencil version of the ANPS. In addition, all participants provided buccal swaps for genotyping of COMT rs#4680 and DAT1 rs#28363170 polymorphisms. The sample

consisted of 358 males and 683 females. Mean age Inhibitors,research,lifescience,medical was 25.42 years (SD = 7.86, age range: 18–76 years). Participants were recruited at the University of Bonn, Germany. The presence of exclusion criteria or former ICD-10 diagnosis of psychopathology was assessed by a self-constructed screening questionnaire. The report of any present or former psychiatric or neurological disorders led to an exclusion from the study. The study protocol adheres to the ethical principles of the Declaration of Helsinki of the World Medical Association only and was approved by the local ethics Inhibitors,research,lifescience,medical committee at the University of Bonn. All participants gave written informed consent to participate in this study. Self-report questionnaire Participants completed the German version of the ANPS personality questionnaire (Davis et al. 2003; Davis and Panksepp 2011). This self-report measure of behavioral dispositions was used because the construction of this inventory was biologically motivated by a theory of basic emotional systems that was validated across mammalian species (Panksepp 1998). Each scale of the ANPS has been built in analogy to the existence of basic emotional neuronal circuits of the mammalian brain. The ANPS consists of 110 items, scaled on a four-point Likert scale ranging from “strongly disagree” to “strongly agree.