What Really Causes ADHD? Early Childhood Stress, Heavy Metal Toxicity, Genetics & More

Last updated: November 27th, 2019

What is the root cause of ADHD? That’s a tough question to answer for most people, because we simply don’t know the exact origin of ADHD at this time.

But, here’s the kicker:

We have some pretty good ideas of what causes ADHD.

So, this article dives into the possible origins of ADHD, and explores concepts like early childhood stress, heavy metal toxicity, genetics, and more.

What really causes ADHD? An introduction to the origins of ADHD…

I’ve been interested in the root cause of ADHD ever since being formally diagnosed with ADHD towards the end of my college career.

Because for a long time, I assumed that I was 100% responsible for my impulsive, reckless, and distracted behavior.

(I do take responsibility for my behavior, by the way.)

But, when you learn about the potential underlying causes of ADHD, you realize that maybe you were born with (or developed) a unique brain style that causes you to do wacky stuff sometimes.

So, this article is an interesting one, because it will help you understand the possible relationships between:

• Early childhood stress and ADHD
• Heavy metal toxicity and ADHD
• Genetics and ADHD
• Food additives and ADHD
• Culture and ADHD
• Diet and ADHD

Let’s get started with one of my favorite theories, which explores the possibility that early childhood stress causes ADHD.

Does early childhood stress cause ADHD?

Dr. Gabor Maté wrote a book called Scattered, which explores the possibility that childhood stress causes ADHD.

In Scattered, Dr. Maté explains that ADHD is not an inherited condition, but rather something that originates as a result of early childhood stresses. Dr. Maté believes that early childhood stresses can influence the first few crucial years of brain and personality development, and lead to ADHD.

Interestingly, Dr. Maté still believes that ADHD is a biological condition. But, he explains that biology is affected by:

• What happens in a person’s life
• What happens in a person’s family
• What happens in a society

Dr. Maté further clarifies his views on his website:

For the most part genes don’t predetermine or “cause” anything that happens – they just lay out a set of potentials that might happen, given the right (or wrong) environmental inputs. Especially in early childhood, our brains are very much affected by social and psychological relationships. And, in fact, for its lifetime the brain is in constant interaction with the environment. So something can absolutely be biological without therefore being written in genetic stone.

So, what are some examples of early childhood stresses that might contribute to an ADHD diagnosis?

• The quality of the relationships the ADHD child is surrounded by
• The amount of structure and security that the family environment provides
• The quality of schooling and extracurricular activities

As you can probably imagine, the average American household is under tremendous amounts of stress, and this may play a role in the American ADHD epidemic.

ADHD affects up to 1 in 20 children in the USA. And, it’s easy to imagine why this may be happening, when you think of ADHD as a potential result of early developmental stress.

American children are under immense pressure to perform well in school, develop competitive skills, and prepare for a successful future. When you combine this external pressure with internal household problems like divorce, stress from work, and the general busyness of the average American lifestyle – this might be the ideal environment for ADHD to flourish.

Luckily, the good news is that Dr. Maté believes that treatment options can be extremely helpful to the ADHD mind. Dr. Maté even goes as far as suggesting that ADHD may be reversible with the appropriate treatments.

Dr. Maté recommends ADHD treatment options such as:

• Counseling to unravel family issues and problems with self-esteem
• Physical self care
• Exercise
• Nutritious diets
• Good sleep hygiene
• ADHD medication
• Outdoor activities
• Meditation

Wouldn’t you know it, these are the same exact treatment options that I frequently write about on ADHD Boss.

These treatments are amazing for anyone with ADHD to take advantage of, regardless of whether ADHD is truly reversible or not.

Is there a connection between heavy metal toxicity and ADHD?

Most people are still unaware of the fact that even a little bit of heavy metal toxicity has the potential to wreak havoc on the human brain.

For example, a recent innovative study shows that baby teeth from autistic children contain more toxic lead compared to teeth from children without autism. The findings of this study indicate that early-life exposure to metals might affect the risk of autism.

This is yet another example of how a child’s environment can increase health risks.

Interestingly, similar studies have shown that autism spectrum disorder (ASD) and ADHD may be related to each other, because these two disorders could share a common causation. According to the World Mercury Project, the growing prevalence of heavy metals may be to blame for neurodevelopmental disorders like ASD and ADHD.

One systematic review published in The Lancet identified five industrial chemicals as developmental neurotoxicants.

These industrial chemicals include:

• Lead
• Methylmercury
• Polychlorinated biphenyls
• Arsenic
• Toluene

Other developmental neurotoxicants listed in The Lancet include:

• Manganese
• Fluoride
• Chlorpyrifos
• Dichlorodiphenyltrichloroethane
• Tetrachloroethylene
• Polybrominated diphenyl ethers

What’s worrying is that ADHD and ASD are often comorbid, which is yet another possible indication that a single toxic source could be causing multiple neurodevelopmental disorders.

One study shows that children living near coal ash storage sites have significantly higher rates of ADHD, allergies, and gastrointestinal issues compared to children who haven’t been exposed to coal ash. The metals found in coal ash include arsenic, lead, mercury, manganese, and cadmium.

Overall, there’s a growing body of research that suggests environmental toxins like heavy metals may contribute to ADHD, ASD, and other neurodevelopmental disorders.

So, it’s in your best interest to reduce your exposure to environmental toxins as often as possible. Especially heavy metals.

To reduce your exposure to heavy metals, you can take these simple precautions:

• Eat leafy green vegetables daily, especially cilantro, which can help you eliminate neurotoxins (this link is a DOC file)

• Consider purchasing a whole house water filter to reduce your exposure to fluoride and chlorine

• Avoid drinking fluoridated tap water if possible (easy if you have a basic water filtration system)

• Drink chlorella daily (chlorella binds to heavy metals)

I add chlorella to every smoothie that I make, because it’s an affordable and extremely healthy green algae that can help your body eliminate heavy metals.

You can get a bottle of Anthony’s Organic Chlorella Powder on Amazon. This is the chlorella that I use.

Do genetics cause ADHD?

Most experts agree that genetics is the most popular, evidence-based theory behind what causes ADHD.

Genetics is also the explanation that has always resonated most with me, personally speaking.

My mother has ADHD. My sister has ADHD as well. ADHD runs in my entire family.

So, ADHD has to be hereditary, right?

One review explains that ADHD has a heritability rate of 70 – 80%. This means there’s a good chance that your ADHD will remain in your family line.

Interestingly, while ADHD is highly heritable, it’s also a multifactorial disorder in which many genes contribute to the condition, rather than just one specific gene.

But, because people with ADHD lack the ability to produce as much dopamine as the average person, most studies involving ADHD and genetics focus on the dopaminergic neurotransmission system.

Of course, just because ADHD is highly heritable doesn’t mean that all cases of ADHD are genetic.

It’s possible that multiple causes contribute to ADHD diagnoses.

Other potential causes of ADHD

While early childhood stress, heavy metal toxicity, and genetics are the three most popular potential causes of ADHD, other possible causes of ADHD include:

• Food additives
• Culture
• Diet

Here’s a brief breakdown of the three other potential causes of ADHD…

Food additives

I wrote a nice little article about the 7 ingredients that can make your ADHD symptoms worse.

In the article, I explained how artificial dyes and sweeteners can contribute to ADHD symptoms.

However, it’s worth noting that some people actually believe that artificial dyes and artificial sweeteners can cause ADHD.

To be fair, it hasn’t been proven that artificial dyes or artificial sweeteners can cause ADHD.

But either way, it’s in your best interest to avoid artificial dyes, sweeteners, and similar food additives (like artificial preservatives).

For example, in European countries, products that contain artificial dyes like Red Dye No. 40 and Yellow Dye No. 5 are required to present warning labels. These warning labels explain that artificial dyes can have adverse effects on children’s attention and behavior. It was a British study conducted in 2007 which concluded that eating artificially colored foods can increase hyperactivity in children.

That’s actually pretty scary, considering that most people in America are still unaware of the possible link between food additives and ADHD.

I urge you and your family to start reading ingredient labels on the foods that you buy (if you aren’t doing so already). This will help you “filter out” bad ingredients from your diet, before you put them in your shopping cart. It also helps to shop at health-conscious food stores like Trader Joe’s or Sprouts whenever possible (depending on your location, of course).

Culture

ADHD diagnoses are increasing around the world.

One could argue that our high-stress, hyper-competitive, technology-oriented culture is creating detrimental changes in the brain that may lead to ADHD.

Because, the reality is that humans have lived in tribes for thousands of years, up until just a few centuries ago.

Industrialization forced people to move to cities between 1870 and 1920. By 1920, more Americans lived in urban areas than rural areas for the first time in U.S. history.

The reality is that human brains still haven’t adapted to life in modern cities. Humans have only lived in cities for a few hundred years.

To put it simply, you have an “ancient” brain that still doesn’t know how to deal with all of the technology, population density, and unnatural stress that comes with modern society.

Could ADHD be the result of a giant “mismatch” between how humans are supposed to live (in small tribes), versus how humans currently live (in crazy, chaotic cities)?

It’s hard to tell.

At the very least, modern day culture contributes to stress.

So, it’s safe to say that modern day culture isn’t helping your ADHD.

As you might have guessed, it’s pretty difficult to overcome the challenges of modern day society. If you’re like most people, then you’re probably forced to live in or near a major city, use a laptop, and deal with high levels of unnatural stress. This is something that everyone has to deal with.

So, I think the best thing that anyone with ADHD can do is form close social ties with people. Your brain is designed to connect with other people. It’s been shown that people who have an abundance of meaningful social relationships live longer, healthier lives. Just make sure to get out there and connect with other people.

There are many people out there who are desperate to connect with someone. It’s easier than ever to go out and socialize, because most people are craving human connection.

Diet

I feel like I’m at my personal best when I avoid eating grains and sugar.

In fact, I enjoy much greater mental clarity and energy when I follow a Paleo style diet in combination with intermittent fasting.

A Harvard study revealed that intermittent fasting can help you live a longer, healthier life.

The researchers found that temporarily restricting your diet (fasting) keeps your mitochondria in homeostasis, and ultimately improves your lifespan.

I do my best work when I’m in a fasted state. I think more clearly, and my ADHD symptoms aren’t nearly as bothersome.

Dr. David Perlmutter, who is the author of the book Grain Brain, has drawn connections between consuming grains and sugar in excess, and suffering from ailments like ADHD and anxiety.

Again, no one knows exactly what kind of influence one’s diet can have on ADHD.

But, I strongly suggest reading Grain Brain, which is listed in my article on the best books for people with ADHD.

Because, if you can become conscious of how certain foods affect your ADHD, then you will enjoy greater mental clarity, energy, and an all-around better life in general.

Closing remarks

No one knows exactly what causes ADHD.

But, there’s enough research to comfortably assume that genetics, early childhood stress, and heavy metal toxicity may all play a role in ADHD.

It’s also possible that food additives, culture, and diet exacerbates ADHD symptoms, or possibly even causes ADHD in certain cases.

There’s still so much that we don’t know about ADHD, so it’s difficult to come to any hard conclusions.

But, if you can just try your best to avoid unnecessary stress, be careful about your diet, and form close social ties with people who you love – then you might be able to limit your exposure to ADHD, and enjoy a much higher quality of life.