What Causes ADHD?
Multiple factors are thought to contribute to what causes ADHD. However, the exact mechanisms behind ADHD are unknown. The majority of these factors are biological in origin and are thought to interact with each other in complex ways. ADHD appears to have been observed to run in families, implying a possible genetic component. This has led to the belief among clinicians that ADHD may be caused by a combination of genes, environment, and slight differences in how the brain is wired.
Potential Causes of ADHD
ADHD is suspected of being influenced by factors such as:
- Premature birth
- Oxygen deprivation or exposure to drugs (including nicotine and alcohol) before birth
- Brain injuries or infections
- Difficult experiences or adversities during early childhood
ADHD and Pregnancy
A degree of ADHD is thought to develop during pregnancy through disruptions to the formation of the frontal lobe. Some cases of ADHD are also thought to occur after birth due to factors such as trauma or infection. These can negatively affect ongoing brain development (e.g. lead poisoning, leukemia treatments, strep bacteria proteins, or the immune system attacking the brain.)
Brain Development and ADHD
Brain regions that are associated with ADHD may also be impacted by being less developed in size due to genetics. This size difference may be small enough for brain imaging to be usable during diagnosis. It is both very subtle, and very persistent over time. Although the size of the brain will normalise by adulthood, the functioning of the brain will not.
Exacerbating ADHD
It is important to remember that other factors may exacerbate certain symptoms of ADHD, but are not believed to directly cause ADHD. These include poor parenting, an excessive intake of sugars, as well as artificial colours and flavours. Scientists continue to debate the links present to this very day.