Understanding the causes of ADHD has been a goal of developmental science for the last several decades. This research has enabled the field to narrow down potential causes to several key contributors. However, there are few specific causes which have been identified in the literature that can cause ADHD on their own.
One of the most common causes of ADHD is genetics, as ADHD is often passed from parent to child. For example, parents of children with ADHD are over 25% likely to have the disorder themselves, and there are often other individuals in the family that share the diagnosis.
Aside from inborn characteristics, ADHD symptoms can also arise from prenatal exposures (e.g., alcohol nicotine), prematurity, lead poisoning, and head trauma, among other causes.
Importantly, research has identified many factors that do not cause ADHD, such as: playing video games, watching TV, immunizations, food additives, eating sugar, or allergies.