More than just Genes? Where does the Environment Fit into the ADHD Story?

ADHD runs in families. Families can create difficult environments and pass on risk genes. Twin studies suggest that familial effects are genetic rather than environmental in origin. If this is the case then why does ADHD appear to correlate with social adversity - in some cases even apparently in the absence of pre-existing genetic risk? In this talk we first use the concepts of gene-environment correlation and gene x environment interaction to explain this apparently contradictory finding in relation to normative environments. We then extend our analysis to the impact of extraordinary environmental exposures such as severe institutional deprivation and put forward the hypothesis that these over-ride background genetic risk levels to directly target the brain regions implicated in ADHD. We conclude the talk by exploring the clinical implications of such a perspective.