This review focuses on the treatment of attention defi cit hyperactivity disorder (ADHD) in adults. It briefl y addresses prevalence, diagnostic and differential diagnostic issues specifi c to adults. Stimulant medication, non-stimulant medication, and psychosocial treatments are thoroughly reviewed. For each class of medication possible mechanism of action, effi cacy and side effects are summarized. Special attention is given to the pharmacological treatment for patients with adult ADHD and various comorbidities. In summary, stimulant medications are most effective and combined medication and psychosocial treatment is the most benefi cial treatment option for most adult patients with ADHD.