ADHD: Nature, Nurture, or Both?

By Eve Kessler, Esq.


A leading researcher explains the interplay of hereditary and environmental risk factors that cause ADHD and provides helpful guidelines for reducing controllable factors that may help alleviate some ADHD behaviors 

“We know that ADHD is hereditary,” says Professor Joel Nigg, a leading researcher and author in the field. Seventy-five percent of ADHD is due to genetics, yet there is no single gene that causes the disorder. Instead, it is best described as a genetic disorder involving many genes. 

But even that is not the whole story, explains Nigg. A growing body of research points to the role of environmental factors that can negatively impact the developing brain and contribute to ADHD and ADHD-like symptoms. (See below for a list of the most common environmental factors.) As exposures accumulate a child might begin to exhibit ADHD-like symptoms, Nigg explains. But because many other factors are involved, it’s hard to know which are the true culprits. 

The bottom line is that nature and nurture both contribute to ADHD and many of the traits commonly associated with it.

Addressing ADHD Behaviors

While the question of causation is interesting, Nigg stresses that when you have a child with ADHD, it’s important to be kind to yourself and look to the future with hope and optimism. “You can’t change what’s past,” he says, referring to factors such as poor maternal health, premature delivery, or post-natal exposure to lead. However, you can reduce some risks and move forward with positive steps, including the following: 

  1. Create a plan with a psychiatric professional, an ADHD coach, or a consultant focused on your child’s specific behavioral challenges. Although medication is not a silver bullet or effective for everyone, many kids with ADHD respond well to it. 
  2. Maintain an even keel when responding to your child’s outbursts and behaviors. Be consistent with your reactions, and try to be on the same page with your spouse and extended family.
  3. Engage in self-care. Ensure your own rest, good health, and lower stress levels. The more stressed you are, the more stressed your kids will be, contributing to an ongoing “negative loop.”
  4. Provide healthy food choices. Shop for fresh, less processed foods, preferably organic. Add oily fish to your meals (eg., salmon, sardines, herring, mackerel), and ask your pediatrician about supplements (fish oil, algae-based Omega 3 supplements, multi-nutrients). Eliminate coffee (until late teen years) and sports drinks, and cut back on excess sugar and food additives. Work with a professional nutritionist or counselor to reduce possible food allergies and sensitivities. Check blood levels for Vitamin D, Omega 3, and Ferritin.
  5. Promote adequate exercise. There is no downside to exercise, says Nigg. It improves mood and overall health. He suggests at least one hour per day of moderate to vigorous exercise, varying the activities to find what works best for your family (eg., free play; organized group sports; individualized activities, such as running, skiing, kayaking, cycling).
  6. Address lead exposure in the home. Test lead levels in tap water and paint (house paint; toys). Be aware of air pollution and airport exhaust. If necessary, install water filters and use good HEPA air filters. Nigg advises beginning your research with the EPA website. 
  7. Recognize stress and trauma, including your own. Nigg notes that kids with ADHD are more sensitive to stress and trauma in themselves, as well as within their families. Because of their impulsivity, lack of self-control, and hyperactivity, they are also more likely to have accidents and suffer from head injuries and emotional trauma. If necessary, get a good assessment to distinguish trauma from ADHD. Nigg suggests finding a clinician for trauma-specific counseling and using cognitive therapy to help with reframing, coping, and creating a resilient mindset. Reduce high-intensity communication within the home. Build social supports for yourself and your kids, and make sure to manage your own personal trauma in addition to theirs.
  8. Teach safe internet and social media use. When it comes to technology, Nigg recommends being acutely involved with your child’s behavior. Monitor content and re-direct your child if they show signs of aggression, depression, or irritability. Negotiate a time limit for use, including before bed. Create an agreement that leaves time for exercise, study, sleep, and social activity, taking into account that, for some gamers, this is their social world. Recognize addictive digital behavior and seek counseling before it gets out of hand.

Potential Environmental Risks

The following list includes factors that may contribute to ADHD or ADHD-like behaviors:

Parent’s Vulnerabilities

  • Fetal Alcohol Syndrome
  • Infections
  • Certain drugs
  • High levels of lead exposure (pre- and post-natal)
  • Maternal metabolic health (eg., obesity; hypertension)
  • High maternal emotional stress or trauma
  • Delivery complications (eg., oxygen deprivation)
  • Poor nutrition

Children’s Vulnerabilities

  • Low birthrate or prematurity
  • Sleep problems
  • Poor nutrition
  • Food sensitivities or allergies
  • High lead levels
  • Automobile exhaust
  • Persistent organic pollutants
  • Traumatic Brain Injury (TBI)
  • Severe early neglect
  • Traumatic abuse
  • Excessive use of media/gaming/internet (especially violence-related)

This article is based on the ADDitude webinar, Genes and the Environment: How Biology and Exposures Contribute to ADHD in Children, by Joel Nigg, Ph.D., Professor in Psychiatry and Behavioral Neuroscience and Director of the Division of Psychology at Oregon Health and Science University, and author of Getting Ahead of ADHD. Eve Kessler, Esq., a former criminal appellate attorney, is the Executive Director of SPED*NET and a Contributing Editor of Smart Kids. 

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