Integrating genetic, psychopharmacological and neuroimaging studies: A converging methods approach to understanding the neurobiology of ADHD

This paper aims to illustrate how combining multiple approaches can inform us about the neurobiology of ADHD. Converging evidence from genetic, psychopharmacological and functional neuroimaging studies has implicated dopaminergic fronto-striatal circuitry in ADHD. However, while the observation of converging evidence from multiple vantage points is convincing, it does not necessarily inform us on how these observations fit together. How does a polymorphism in a (dopamine) risk-gene for ADHD translate into a neurobiological substrate and result in behaviors that warrant a diagnosis of ADHD in a developing child? To illustrate how integrating multiple methods may help address this issue, we discuss studies combining genetics, neuropsychopharmacology and neuroimaging approaches. We show how investigators are using these approaches to map the effects of ADHD risk-genes, and common ADHD-treatments on neurobiological measures. Given its central role in both ADHD and in stimulant treatment, the dopamine transporter gene is frequently discussed as an example. The studies discussed here demonstrate that a converging methods approach is a potentially powerful tool in unraveling the neurobiology of ADHD. These approaches may suggest new avenues for research, as well as point out new directions for the development of targeted treatments for this disorder. (c) 2007 Elsevier Inc. All rights reserved.