Neurobiology of attention deficit hyperactivity disorder (ADHD)

Attention deficit hyperactivity disorder (ADHD) is a common condition associated with long-lasting psychosocial functioning difficulties and high psychiatric morbidity. ADHD is a heterogeneous syndrome in its clinical presentation and probably in its aetiology. Nevertheless, it can be understood as a spectrum of multifactorial cognitive, emotional, and behavioural dysfunctions under the influence of genetic and environmental factors, mainly perinatal. For several decades, the dopaminergic dysfunction hypothesis has been one of the possible pathways in the origin of ADHD. Still, other neurotransmission systems also appear to play a role, as evidenced by the recent therapeutic development of noradrenergic agonists in this indication.