Cardo E, Nevot A, Redondo M, Melero A, de Azua B, García-De la Banda G, Servera M
Hospital Son Llàtzer, Baleares, España.
Rev Neurol. 2010 Mar 3;50 Suppl 3:S143-7.
When the frequency of a gene in the general population exceeds 1%, is not considered a random mutation but a mutation that has been positively selected during evolution. The high prevalence of attention deficit/hyperactivity disorder (ADHD) from 5-10% and its association with the seven-repeat allele of DRD4, which is positively selected in evolution, raising the possibility that ADHD increases the reproductive fitness of the individual and/or group. One of the main characteristics of ADHD is its diversity and is a well recognized fact that diversity confers many benefits to a population (eg. immunity).
This article discusses the various studies that support this hypothesis and offers further explanations on the prevalence, age distribution and sex distribution of the severity and heterogeneity of ADHD.
It is possible that the presence of altered gene combinations, as in ADHD, can bring concrete benefits to society but are detrimental to the individual.