Another strong candidate gene for ADHD, based on pharmacological data analysis of animal models and association studies, is the gene encoding Brain-Derived Neurotrophic Factor (BDNF). Studies investigating association of a genetic variant in this gene in children with ADHD and controls have, however, shown controversial results. In a high-powered association study in 1445 adult ADHD patients and 2247 controls from IMpACT no association between this genetic variant and adult ADHD was found. This confirms that the BDNF variant is not a risk factor for adult ADHD (Ribases et al., presented at the ECNP Congress 2009).
So far, risk genes for ADHD have primarily been derived from animal models and pharmacological studies. Recently, it has become possible to search for such genes on a genome-wide basis, without prior hypotheses about specific candidate pathways. This approach has delivered a first gene for ADHD in children, CDH13, encoding a cell-adhesion gene with a role in early brain development (Lasky-Su et al., 2008; Lesch et al., 2008). A preliminary analysis in IMpACT suggests that this gene also plays a role in the adult form of the disorder (presentation at the ECNP Congress 2009).
Additional genetic analyses, both from earlier candidate-gene research in children and from genome-wide association studies, are currently ongoing within IMpACT. With the adult form of ADHD being the most severe one, the findings of the IMpACT project, focusing on the genetics of ADHD in
|Contact: Sonja Mak|
European College of Neuropsychopharmacology