“…This imbalance plays a crucial role in an individual's disease susceptibility, and studies on clinical samples have shown that DAT1 was associated with different psychopathological difficulties, from infancy to adulthood, including attention-deficit hyperactivity disorder (ADHD) [50][51][52][53], conduct disorder [54], affective disorders [55,56], post-traumatic stress disorder [57], and eating disorders [58,59]. A couple of studies have focused on the general population, showing significant associations with children's temperament traits (including uninhibited traits, negative emotionality, aggressive and impulsive traits) [60][61][62], symptoms of ADHD [63,64], and other subclinical forms of psychological difficulties in both internalizing and externalizing areas [65][66][67][68]. However, to date, only a few studies have focused on early childhood [61,62], and to our best knowledge, no studies have explored the possible association between children's DAT1 polymorphism with children's dysregulation profile (DP), an empirically-based profile of poor self-regulation among early childhood [69], with which prospective associations with psychopathological difficulties have been evidenced over time [70][71][72].…”