Environmental factors as a cause of ADHD

Environmental factors are all external and internal positive and negative influences on the individual. Intense negative environmental influences are stressors. Stressors is thus merely another term for stressful environmental influences. Illnesses are stressors as well as accidents or psychological stress.

Gene-environment interaction is a fundamental biological concept for the development of different behavioral patterns and mental disorders. It describes that environmental influences with different gene structure have different effects and do not necessarily add up.

ADHD has several roots:

• Genetic factors such as gene mutations (gene variants that arise independently of environmental influences/stress and are inherited over the long term)
• Pure environmental influences (e.g. encephalitis, early childhood stress) and
• Epigenetically anchored environmental influences (different gene expressions that result from environmental influences (stress) and are heritable over a few generations).

Any one of these roots alone can lead to ADHD, but most often several of these roots act together. In addition, they interact (gene x environment interactions). See more at ⇒ Genetic and epigenetic causes of ADHD.