Aim: To update the knowledge currently available on the genetic foundations of attention deficit hyperactivity disorder (ADHD). The presentation will focus especially on recent data concerning adults.
Development and conclusions: ADHD is one of the most prevalent neuropsychiatric disorders among the general childhood population. In recent years it has been shown that it often progresses into adulthood. The results from studies of families, twins and adopted children display a high degree of familial aggregation. Molecular genetics studies have brought to light positive associations with different genetic polymorphisms in neurotransmitter systems involved in the pathophysiology of ADHD, mainly with the dopaminergic, serotoninergic and noradrenergic, and neurotrophins such as the brain-derived neurotrophic factor (BDNF). The causation of ADHD is still largely unknown but the different studies published to date dealing with the genetic foundations of the disorder suggest that genetics play an important role, its inheritance is complex and it is modulated by environmental factors. ADHD in adults can be a good model for studying the genetic foundations of ADHD.