The genetics of attention-deficit/hyperactivity disorder

Expert Rev Neurother. 2009 Oct;9(10):1547-65. doi: 10.1586/ern.09.78.


Attention-deficit/hyperactivity disorder (ADHD) is a complex neurodevelopmental disorder that almost certainly represents the common outcome of multiple causal pathways and it is now generally accepted that genetic factors make a significant contribution to these pathways. Behavioral studies suggest a heritability of approximately 0.76. While molecular genetic approaches have identified a range of potential candidate genes, it is now clear that the genetics of ADHD are characterized by a number of genes each of which makes a small but significant contribution to the overall risk. Several genome-wide linkage studies have been conducted and, although there are considerable differences in findings between studies, several regions have been supported across several studies (bin 16.4, 5p13, 11q22-25, 17p11). The contribution of several candidate genes has been supported by meta-analyses (DRD4, DRD5, DAT1, HTR1B and SNAP25). Genome-wide association scans are starting to appear but have not yet had sufficient power to produce conclusive results. Gene-environment interactions, which are as yet relatively understudied, are likely to be of importance in fully understanding the role of genes in ADHD and will be discussed.

Publication types

  • Review

MeSH terms

  • Attention Deficit Disorder with Hyperactivity / etiology
  • Attention Deficit Disorder with Hyperactivity / genetics*
  • Dopamine Plasma Membrane Transport Proteins / genetics
  • Environment
  • Genetic Predisposition to Disease*
  • Genetics*
  • Genome-Wide Association Study / methods
  • Humans
  • Polymorphism, Single Nucleotide
  • Receptors, Dopamine / genetics
  • Receptors, Dopamine / metabolism
  • Receptors, Serotonin, 5-HT1 / genetics
  • Synaptosomal-Associated Protein 25 / genetics


  • Dopamine Plasma Membrane Transport Proteins
  • Receptors, Dopamine
  • Receptors, Serotonin, 5-HT1
  • SNAP25 protein, human
  • Synaptosomal-Associated Protein 25