[Attention deficit disorder and hyperactivity: a pattern of evolution?].
BACKGROUND
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).


METHODS
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.


CONCLUSIONS
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.
Cardo
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E
Hospital Son Llàtzer, Baleares, España. ecardojalon@gmail.com
Nevot
A
A
Redondo
M
M
Melero
A
A
de Azua
B
B
García-De la Banda
G
G
Servera
M
M
D001289:Attention Deficit Disorder with Hyperactivity / Q000453:epidemiology / Q000235:genetics*; D005075:Biological Evolution; D005787:Gene Frequency; D056084:Genetic Fitness / Q000235:genetics; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation; D006801:Humans; D050638:Receptors, Dopamine D4 / Q000235:genetics*; D012641:Selection, Genetic
C493599:DRD4 protein, human; D050638:Receptors, Dopamine D4