The ADHD Gene?

Some researchers claim that a person's genes cause ADHD. The DRD4 gene with a 7-repeat allele has occurred more often in ADHD populations. However, as noted in the following article, this gene occurs in almost half of the population in the America's and it occurs in 20% of the population worldwide. Always remember, there are many people with ADHD who do not have the genetics associated with ADHD, and there are many people without ADHD who have the genetics associated with ADHD. Conclusion: There are many factors other than genetics that account for the occurrence of an ADHD diagnosis. http://tools.medicine.yale.edu/kidd/www/330.pdf