Attention-deficit hyperactivity disorder causes

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Charmaine Patel, M.D. [2], Haleigh Williams, B.S.

Overview

There are no established causes of ADHD. Studies suggest that ADHD results from a complex interaction between genetic and environmental factors.^[1]

There are no established causes of ADHD. ADHD likely results from an interaction between genetic factors and external factors, including trauma or exposure to toxins. The genetic component of the disease has been demonstrated by the increased likelihood that a person for whom ADHD runs in his/her family is more likely to have ADHD than a person with no family history of ADHD. There is also a familial transmission of ADHD which does not occur through adoptive relationships. Twin studies indicate that the disorder is highly heritable and that genetics account for about three quarters of the total ADHD population, leaving the contribution of non-genetic factors at around 25%.^[1]

A link has been identified between traumatic brain injury and the onset of ADHD-like symptoms in some adults. Brain injury may be one possible non-genetic cause of ADHD.^[2]

↑ ^1.0 ^1.1 OurMed. (2010). “Attention-deficit hyperactivity disorder.”
↑ Ilie G, Vingilis ER, Mann RE, Hamilton H, Toplak M, Adlaf EM; et al. (2015). “The association between traumatic brain injury and ADHD in a Canadian adult sample”. J Psychiatr Res. 69: 174–9. doi:10.1016/j.jpsychires.2015.08.004. PMID 26343610.