ADHD can be explained as an “epigenetic” manifestation. The term epigenetic refers to a combination of genetic inheritance and the environment. For example, we may carry a gene but whether it is activated or not can depend on stressors in the environment. There are many environmental “stressors” which may influence the development of the disorder and are discussed in more detail in the book I am writing[1]. In the same way the genetic factors are not completely worked out yet, neither are the environmental risk factors. Here are some proposed risk factors or environmental mediators for the development of ADHD:
- Premature birth, low birth-weight and/or pregnancy and delivery complications (e.g., toxemia, eclampsia) [88]
- Prenatal smoking and alcohol exposure [89-92]
- Maternal mental-ill health disorders including bi-polar and depression [93]
- Exposure to lead or PCBs during early childhood [94, 95]
- Nutritional deficiencies in omega-3 highly unsaturated fatty acids (HUFAs) and other key brain-selective nutrients including zinc, iron and iodine [96, 97]
- Increase in the “Western diet” (e.g., chemically altered and heavily processed foods rich in sodium, sugars, saturated fats) [35, 98, 99]
- Psycho-social adversities [100]
More is discussed on the potential role of HUFAs in the etiology of ADHD in the Neuroscience and Nutrition section of the website.
[1] In preparation: What does it mean I’ve got ADHD? A Handbook on Attention Deficit Hyperactivity Disorder (ADHD): Facts, Myths and Theories