Association study of brain-derived neurotrophic factor (BDNF) and LIN-7 homolog (LIN-7) genes with adult attention-deficit/hyperactivity disorder.

Attention-deficit/hyperactivity disorder (ADHD) is a common psychiatric disorder with a large genetic component that has been shown to persist into adulthood in 30-60% of childhood ADHD cases. Adult ADHD confers an increased risk of ADHD in relatives when compared to childhood ADHD, possibly due to a greater genetic liability than the childhood form. Brain-derived neurotrophic factor (BDNF) is a neurotrophin expressed in the brain throughout life and is involved in survival, differentiation, and synaptic plasticity of several neuronal systems including dopaminergic pathways.

Investigation of the dopamine D5 receptor gene (DRD5) in adult attention deficit hyperactivity disorder.

Several lines of evidence from neuroimaging, pharmacology and genetics support the involvement of the dopaminergic system in the etiology of Attention Deficit Hyperactivity Disorder (ADHD). Previous candidate gene studies have investigated the association between a dinucleotide (CA)(n) repeat polymorphism, located 18.5 kb from the start codon of the DRD5 gene, and ADHD.