[Attention deficit hyperactivity disorder (ADHD): etiology, diagnosis and treatment].

ADHD is a highly hereditary and persistent disorder with structural and functional abnormalities of the fronto-striatal circuits at group level as revealed by neuroimaging studies. There is no psychological or biological diagnostic test available. The diagnosis 'ADHD' is made on the basis of a careful and systematic review of the clinical characteristics as obtained from reports by parents, teachers and the child itself, and of own observation. Effective treatments include the prescription of medication (particularly psychostimulants) and behaviour therapy. Medication is more effective than behaviour therapy in affecting the core symptoms of ADHD and is therefore the first choice of treatment, except in children under 5 years of age. Treatment should be monitored at regular times. In case of insufficient response to monotherapy, combination treatment should be offered. Early recognition and appropriate assessment and treatment of ADHD requires collaboration between general practitioner, primary care psychologist, educational system, school doctors and nurses, child guidance system, paediatricians and child mental health system and child psychiatry, and adult psychiatry.