DA appears also to play a role in emotionality and rash action. Unusually high levels of DA are associated with the three dimensions of borderline personality disorder: emotional dysregulation, “impulsivity,” and cognitive-perceptual impairment (Friedel, 2004) and are thought to be a central factor influencing the ill-considered behaviors observed in ADHD (Winstanley et al., 2006). They have been associated with both behavioral disinhibition (Cardinal & Everitt, 2004) and with high levels of novelty seeking (Stuettgen, Hennig, Reuter, & Netter, 2005). High levels of DA have repeatedly been associated with a tendency to act, or to engage in approach behaviors (Depue, 1995; Depue & Collins, 1999; Spoont, 1992; Zald & Depue, 2001) and with increasing reward-seeking and risk-taking behaviors (Spear, 2000).
