The association of alcohol /substance use disorder and attention deficit hyperactivity disorder (ADHD) is a frequently reported condition. The comorbidity of these two diseases both compromises treatment compliance and increases mortality and morbidity rates. The medical treatments used in ADHD treatment are also very limited due to their potential for abuse. In this case report, the regression of attention deficit symptoms and improvement in the neuropsychometric tests due to atomoxetine treatment in opiate use disorder patient will be presented.