by Eric Schuman
Research has shown that ADHD (Attention deficit / hyperactivity disorder) is strongly influenced by genes. It seems as if it is related to a problem within the dopamine reward system of the brain. Difficulties with this system could be the reason that people with ADHD and ADD (attention deficit disorder) seem to have trouble staying focused.
The bad side of ADHD is pretty obvious: It makes people seem unfocused, hyperactive. But new research proposes that it has benefits. Why else would the genes associated with ADHD still be in the gene pool? Researchers Dan Eisenberg of Northwestern University and Ben Campbell of the University of Wisconson, Milwakee, think they have an answer. In a study published in BMC Evolutionary Biology, they posit that the sort of activities associated with ADHD—a want of novelty, behavioral flexibility, being hyper-aware in environments—were in fact advantageous to nomadic herdsman. They go on to link ADHD to obesity. In the modern world where a scarcity of food (for many but clearly not all) no longer exists, dis-inhibition of seeking pleasure from things like food become exaggerated, leading to obesity. Many children with ADHD have higher BMI’s (body mass index) than their peers, before they go on medications that often lead to weight loss, they point out.
Campbell, Eisenberg and their collegues (2008) studied a tribe in Kenya. One half had stayed nomadic, and the other had become agricultural. They explain that within a nomadic context, the ADHD genes are beneficiary. When in a more sedentary context, those same genes result in increased weight and malnutrition. This allele that contains these genes is, of course, connected with ADHD. Therefore, it seems ADHD is both positive and negative. (more…)