Attention deficit disorder is the most commonly diagnosed problem in childhood, and reliable studies show that more than half of people diagnosed in childhood continue to have this problem in adulthood. The presence of ADHD in adolescence and adulthood is associated with enormous functional consequences on the academic and work performance of those who suffer from it. Historically, ADHD has been defined by three types of symptoms: cognitive deficits (difficulties in attention and executive function), impulsivity and hyperactivity. However, its clinical characterization is currently incomplete, as well as its delimitation from other psychopathological entities is imprecise. This project seeks to: a) explore new symptomatic-etiological dimensions, such as motivational, affective-emotional and cognitive-behavioral changes; b) study their comorbidities in both axis I and axis II of the DSM-IV classification; c) establish indicators that favor the differential diagnosis of other psychiatric pathologies that present symptomatic overlap, in particular, of bipolar disorder and personality disorders.