ADHD is one of the most prevalent childhood psychiatric disorders. It is characterized by inattention, hyperactivity and impulsivity and is estimated to affect 5% of the worldwide population. Until recently, symptoms were thought to ameliorate with age. However, a recent 10 year follow-up study indicated that 35% of pediatric patients still meet criteria and it's been estimated that affects between 3 and 7% of adult population. Even thought the exact neurobiological substrate of ADHD still unclear, genetic, preclinical and clinical studies point to dopaminergic and/or noradrenergic alterations. Neural activity and grey matter volume decreases in dopamine related regions also corroborate such deficits. By performing a time estimation fMRI task, our results provide evidence that temporal processes, in addition to cognitive (i.e., attention) and motivational/emotional domains might be a third dissociable neuropsychological component that affects ADHD.