Is ADHD Genetic? What the MTHFR

Is ADHD Genetic?

Many people believe ADHD is genetic. Often when a child is diagnosed with ADHD, a parent or parents will realize they also have similar symptoms. There often seems to be someone else in the family with symptoms, if not an official diagnosis.   So is there a gene responsible?

The Human Genome Project, completed in 2003, discovered that a gene named MTHFR (methylenetetrahydrofolate reductase) was defective in some people.

I recently found out that I have this defective MTHFR gene, as does my daughter, so I thought I would share with you what I’ve found out about it and how it relates to ADHD and many other health issues. 

Image courtesy of

Image courtesy of

What is MTHFR?

MTHFR stands for methyltetrahydrofolate reductase and it’s an enzyme which enables the folate in our diets to be converted to the active form called 5-Methyltetrahydrofolate.1

What is Folate?

To be clear Folate is NOT Folic Acid.   Folate is Vitamin B9. Folic Acid is a synthetic product and does not occur naturally in nature. Folic Acid can only be utilised by the body after undergoing various conversions. In a person with an MTHFR defect these conversions are unable to occur.

Why is folate so important?

The body requires folate to be converted to the active 5-MTHF, with the help of co-factors, for many functions including:

  • Correct cellular function
  • Synthesis of DNA, RNA and SAMe
  • Amino acid metabolism for neurotransmitter, serotonin, dopamine and norepinephrine1 production and detoxification
  • Platelet production
  • Formation and maturation of red and white blood cells
  • Essential for detoxification of homocysteine


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So what does a healthy MTHFR gene do in the body?

An MTHFR gene that is doing its job correctly means your chances of eliminating toxins and heavy metals are greatly improved reducing your risk for a range of health issues.

The MTHFR gene will commence a chemical process with multiple steps known as methylation.   Methylation is a core process that occurs in all cells to help your body make biochemical conversions.

In summary, the methylation process works as follows:

  • The MTHFR gene produces the MTHFR enzyme.
  • The MTHFR enzyme converts folate (B9 or folic acid) to 5-methyltetrahydrofolate (5-MTHF).
  • 5-MTHF assists in the conversion of homocysteine to methionine. Methionine is important for making proteins, utilizing antioxidants and helping to process fats in the liver. Methionine is useful to protect against depression and inflammation within the body.
  • Once in the liver, Methionine is converted into SAMe (s-adenosylmethionine). SAMe protects against inflammation and supports a healthy immune function as well as breaking down serotonin, dopamine and melatonin. SAMe is also important for the growth, repair and maintenance of cells.

What happens when an MTHFR gene is defective?

  • The defective gene produces a defective enzyme resulting in an inability to detox heavy metals and toxins meaning you may end up with high copper or high mercury levels.
  • A high copper level conversely causes zinc levels to fall. As I wrote in my last post (Can Nutrients Cure ADHD?), there is a link between high copper/low zinc and ADHD symptoms. It can also contribute to depression, acne, headaches, sensitive skin, lowered immunity, thyroid issues and adrenal stress.
  • High copper can also make it difficult to raise iron levels, including ferritin. Low iron levels are commonly found in children with ADHD.
  • Folate vitamins are not properly broken down causing high homocysteine which increase the risk for coronary heart disease and dementia.
  • Homocysteine is not properly converted to glutathione which is the body’s primary antioxidant and detoxifier. Low glutathione makes you more susceptible to stress and less tolerant to toxic exposures. This increased oxidative stress and accumulation of toxins in the body can lead to premature ageing.
  • Homocysteine is not properly converted to methionine which can raise the risk of anemia, increased inflammation and free radical damage and a lower production of SAMe.
  • A lower production of SAMe can increase the risk of depression.
  • Because of the above, a defective MTHFR gene can increase your risk for many conditions such as:


o   Addictive behavior

o   Alcoholism

o   Allergies

o   Alzheimer’s

o   Anxiety

o   Autism

o   Bi-polar

o   Blood clotting

o   Cancer

o   Cardiovascular Disease

o   Cervical Dysplasia/Cervical Cancer/HPV

o   Chemical Sensitivities

o   Chronic Fatigue Syndrome

o   Chronic Viral Infection

o   Cleft Palate

o   Congenital Heart Defects

o   Chronic Constipation

o   Depression

o   Diabetes

o   Down’s Syndrome

o   Epilepsy

o   Erectile Dysfunction

o   Fibromyalgia

o   High Homocysteine

o   Infertility

o   Migraine

o   Multiple Sclerosis

o   Neural Tube Defects

o   Neuropathy

o   Parkinson’s

o   Polycystic Ovarian Syndrome (PCOS)

o   Pulmonary Embolism

o   Recurrent miscarriage

o   Schizophrenia

o   Spina Bifida

o   Vitiligo

How do I find out if I have a defective MTHFR gene?

  • A simple blood test can test for the genetic mutation.
  • Find an integrative practitioner who is familiar with this issue and discuss testing with them.

So what can you do about it?

Defective genes can’t be altered but you are able to minimize problems by helping it to do its job.

  • First and foremost find an integrative practitioner who understands how to treat this. Don’t try and treat yourself.
  • because this defective gene does not convert folic acid to the active form it builds up in the body which can be harmful so avoid supplements of folic acid and processed foods containing folic acid. It is commonly found in bread.
  • Eat healthy foods containing folate such as green leafy vegetables
  • Supplement with the active form of folate methylfolate or 5-MTHF.
  • Avoid the synthetic version of B12 (cyanocobalamin) and instead use the more bioavailable form (methylcobalamin).
  • Use the version of B6 called P-5-P.
  • Vitamin C helps lower high levels of copper via detoxing.
  • Zinc can be used to lower copper levels.
  • Repair the digestive system
  • Follow clean eating diets such as Paleo or GAPS diets
  • Avoid exposure to toxins wherever possible
  • Reduce stress in your life as if the stress response is using up methyl groups which are not being created due to this genetic mutation then there will be a shortage which in turn will affect other systems like the brain, thyroid function, fatigue etc.
  • Contact MTHFR Support Australia at

Finding out about the MTHFR gene and its possible effects has added another piece to the health puzzle and I can clearly see the total picture emerging now. Reasons why I’ve felt the way I have in the past, despite following a healthy lifestyle. The protocol I have been following in recent months is much the same, but it has given me a greater understanding of why I’m doing what I’m doing and the importance of continuing with it in order to feel better and avoid future health problems. It has also prompted me to encourage close family members to be tested.

Useful links:

Informative MTHFR Support website

Dr. Ben Lynch’s book “Dirty Genes”

National Library of Medicine MTHFR information page

A map of all the possible methylation pathways

Symptoms of methionine deficiency

The author, Vivian Dunstan, is Founder & CEO of ADHD Support Australia, ADDCA trained ADHD Coach, facilitator of Parenting Children with ADHD – a 6-week online course, certified PEERS Social Skills for Adolescents and Young Adults program facilitator, Digital Addiction & Wellness Educator and facilitator of 6-week online Digital Detox Program, non-practising teacher, woman with ADHD and an ADHD parent.