A recent study by the American Academy of Pediatrics links Organophosphate Insecticide exposure to ADHD in children between 8 and 15. From the medical journal Pediatrics -
Cross-sectional data from the National Health and Nutrition Examination Survey (2000–2004) were available for 1139 children, who were representative of the general US population...One hundred nineteen children met the diagnostic criteria for ADHD. Children with higher urinary dialkyl phosphate concentrations, especially dimethyl alkylphosphate (DMAP) concentrations, were more likely to be diagnosed as having ADHD... For the most-commonly detected DMAP metabolite, dimethyl thiophosphate, children with levels higher than the median of detectable concentrations had twice the odds of ADHD.
While correlation is not causation and more studies need to be done in order to prove causation, it is worth noting that these Organophosphates work by disrupting the central nervous system of insects by affecting the chemicals in their brains. I am in no way a scientist but to me, this study compounded with how these chemicals actually work do much to reinforce my buying practices of organic fruit and vegetables. Just ask Ethan.