Genetics of ADHD: Is ADHD Inherited?

FasTreat Team

The question of what causes ADHD has puzzled scientists and medical professionals for years, and there is no definitive answer. The development of ADHD is likely influenced by multiple factors rather than a single root cause.



Genetics and ADHD


Research indicates that genetics play a significant role in the development of ADHD. Like other inheritable conditions such as heart disease and certain cancers, ADHD tends to run in families. Studies show that a child with ADHD is four times more likely to have a relative with the condition, and a third of fathers who had ADHD as children also have a child with ADHD. The heritability of ADHD is estimated to be 0.77, indicating a strong genetic influence, comparable to conditions like schizophrenia or bipolar disorder.



Nature vs. Nurture Debate


While some believe that environmental upbringing can contribute to ADHD, the evidence predominantly supports genetic influences. For instance, studies have found a higher frequency of ADHD in siblings compared to half-siblings or adopted children raised in the same environment. This suggests that genetic factors are more influential than the home environment. Additionally, research involving twins has shown a higher concordance for ADHD among identical twins compared to non-identical twins.



Environmental Factors and ADHD


Beyond genetics, various environmental factors may also contribute to the risk of developing ADHD. These include:


  • Maternal Substance Use: Exposure to drugs and alcohol in utero has been linked to a higher risk of ADHD. For example, children of mothers who used opioids during pregnancy are shown to have more than double the risk of developing ADHD.
  • Brain Injuries: There is some evidence that head trauma, such as a traumatic brain injury (TBI), can increase the likelihood of developing ADHD. A study found that 62% of children with TBI later developed ADHD, compared to only 15% of children without TBI.
  • Psychosocial Factors: Conditions like an unsupportive home environment, poverty, or a chaotic household can also influence the development or severity of ADHD symptoms.


While genetics are a major factor, the exact causes of ADHD involve a complex interplay of multiple elements. This complexity means there is no single cause for ADHD but rather a combination of genetic and environmental factors that need to be considered when looking for treatments.

This content does not provide medical advice. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read from FasTreat’s content. If you think you may have a medical emergency, immediately call your doctor or dial 911.