ADHD : What Causes ADHD ?

Share it now

Causes of ADHD

There may be several different "causes of ADHD" just as there are different types of ADHD. The most recent research models describing "Attention Deficit Hyperactivity Disorder" suggest that several areas of the brain may be affected by ADHD. These include the

  • frontal lobes
  • inhibitory mechanisms of the cortex
  • limbic system
  • reticular activating system


Each of these areas of the brain is associated with various functions, or qualities, or abilities.

What Causes ADHD

The most recent models describing what is happening neurologically in the brains of people with Attention Deficit Disorder suggest that several areas of the brain may be affected by the disorder, including the Frontal Lobes, the Inhibitory Mechanisms of the Cortex, the Limbic System, and the Reticular Activating System. Each of these areas or systems of the brain is associated with various functions of the brain.

Neurotransmitters such as Dopamine work to activate brain cells, and regions of the brain. Too much activation, or too little, can cause ADHD symptoms. One-third of the neurotransmitters in the brain are glutamate, and brain research is now looking at the intricate relationships between glutamate, dopamine, and norepinephrine in the functioning of the pre-frontal cortex. Glutamine is the pre-curser of glutamate. Research is revealing that the glutamate network neurotransmissions from the pre-frontal cortex to other areas of the brain are enhanced by dopamine and norepinephrine. Too little dopamine or norepinephrine is a problem, and too much is a problem. And the importance of glutamate in PFC functioning is beginning to come to the forefront in research.

Brain imaging gives new insight into underlying cause of ADHD

Brain imaging gives new insight into underlying cause of ADHD

Neurological Causes of ADHD

The frontal lobes help us to pay attention to tasks, focus concentration, make good decisions, plan ahead, learn and remember what we have learned, and behave appropriately for the situation.

The inhibitory mechanisms of the cortex keep us from being hyperactive, from saying things out of turn, and from getting mad at inappropriate times, for examples. They help us to "inhibit" our behaviors.

It has been said that 70% of the brain is there to inhibit the other 30%.

When the inhibitory mechanisms of the brain aren't working as hard as they ought to, then we can see results of what are sometimes called "dis-inhibition disorders" such as impulsive behaviors, quick temper, poor decision making, hyperactivity, and so on.

The limbic system is the base of our emotions and our highly vigilant look-out tower. If over-activated, a person might have wide mood swings, or quick temper outbursts. He might also be "over-aroused," quick to startle, touching everything around him, hyper-vigilant.

A normally functioning limbic system would provide for normal emotional changes, normal levels of energy, normal sleep routines, and normal levels of coping with stress. A dysfunctional limbic system results in problems with those areas.

The frontal lobes help us to pay attention to tasks, focus concentration, make good decisions, plan ahead, learn and remember what we have learned. The frontal lobes also help us to behave appropriately for a given situation. Emotional issues such as anger, frustration, and irritability that come on impulsively in some types of ADHD probably come from the pre-frontal cortex.

The inhibitory mechanisms of the cortex keep us from being hyperactive, from saying things out of turn, and from getting mad at inappropriate times, for examples. These inhibitory mechanisms of the cortex help us to "inhibit" our behaviors. When the inhibitory mechanisms of the brain aren't working as efficiently as they ought , then we can see results of what are sometimes called "dis-inhibition disorders" such as impulsive behaviors, quick temper, poor decision making, hyperactivity, and so on.

Attention Deficit Disorder might affect one, two, or all three of these areas, resulting in several different "styles" or "profiles" of children (and adults) with Attention Deficit Hyperactivity Disorder.

Back to "What is ADHD"? index


This book section: What is ADHD?

Douglas Cowan, Psy.D., M.S. is a licensed Marriage and Family Therapist in Tehachapi, CA who has been a counselor to children, teens, and adults helping them to overcome ADHD, find relief for depression or anxiety, and solve other problems in life since 1989. He served on the medical advisory board to the company that makes Attend and Extress from 1997 through 2011, and he is the Editor of the ADHD Information Library online resource at http://newideas.net/. His weekly ADHD Newsletter goes out to 9,500 families. Visit his website at http://DouglasCowan.me for more information on achieving greater health, personal growth, Christ-centered spirituality, stress management, parenting skills, ADHD, working out the stresses of being a care-giver to elderly parents and also being a parent to teenagers, or finding greater meaning in retirement years, Dr. Cowan can be a valuable resource to you.

Counselor counseling Tehachapi for ADHD, depression, anxiety, and more.

Douglas Cowan, Psy.D., MFT
27400 Oakflat Dr.
Tehachapi, CA 93561
(661) 972-5953

PDF of this page: What causes ADHD?

Share it now

Mineral Deficiencies vs ADHD

Share it now

David, from England, wrote:

I am following your work with great interest as I am trying to get more information about the subject of ADD / ADHD for a friend of mine who was put in charge of such a child at school. She was given no training for this work nor was she given any backup. She was relieved to find that she was not the only one with this problem!

Although the child has finally been moved to another specialized school, it is likely that she will meet the problem again and so I am forwarding any relevant information to her that I can find.

Best regards, and carry on the good work, David

From "Sunday Times", July 1997 London, UK

the ADHD diet is available in full at ADHD diet information site click here

Go to the ADHD Diet Information site to get the full ADHD diet in eBook PDF format, including our UPDATES for 2013. We also have the full 21 minute information video on our ADHD eating program.

Zinc Diet Reduces Violence in Youths

Steve Connor, Science Correspondent

"Scientists have discovered a link between violent behaviour and a chemical imbalance in the body that can be treated by diet. It raises the possibility of treating antisocial individuals with special nutrition.

Studies carried out on 135 males aged between 3 and 20 with a history of violence have found that such individuals are much more likely to have high levels of copper and low levels of zinc compared with non-violent people. Scientists believe such minerals influence behaviour because the body uses them to make chemical transmitters in the brain."

The article goes on to refer to the work of Dr. William Walsh of the Health Research Institute in Naperville, Illinois.

Further, "preliminary experiments have shown that altering the diet of violent males can improve their behaviour".

"It usually takes two to three months to overcome the copper-zinc imbalance."

"Copper and zinc tend to be concentrated in the hippocampus of the brain and the hippocampus is known to be associated with stress control".

"Zinc deficiencies in juvenile offenders were also found in an unpublished study in Britain, said Dr. Neil Ward, a senior lecturer in analytical chemistry at Surrey University.

"We think that it is a direct result of exposure to heavy metal toxins such as cadmium and lead which prevent the absorption of zinc. The people we studied had a poor diet with excessive amounts of sugar and alcohol, which is also known to reduce zinc absorption," Ward said."

"Stephen Schoenthaler, a leading authority at California State Institute on the role of diet in criminal behaviour, said Walsh's conclusions were plausible. "He is more right than wrong...""


02/August/1997 "Sunday Telegraph", London, U.K.

Test Offers Cure for Violent Children

by Victoria Macdonald, Health Correspondent

(With reference to Attention Deficit Hyperactivity Disorder information)

CHILDREN who are aggressive, violent and disruptive at home and school are showing marked improvements after taking a simple £11 laboratory test that can show they are suffering from a chemical imbalance.

The urine test detects kryptopyrrole, a by-product of pyroluria, which means the body is depleted of zinc and vitamin B6. These are needed to control mood and behaviour.

By identifying the condition, children are able to be given supplements to correct the metabolic imbalance.

The Hyperactive Children's Support Group, based in Chichester, is pressing for wider use of the test because it fears disruptive children are being written off as "incurably bad". Sally Bunday, founder of the group, said: "Some of these children are on their last chance at school or have been expelled, or have already been in trouble with the police. All have shown some improvement and in a few cases it has been a remarkable improvement."

The test is carried out at the Bio Lab Medical Unit in London.

Based on studies carried out in Victoria, Canada, by Dr Abraham Hoffer, a psychiatrist and specialist in schizophrenia, it is then decided what level of supplements to give the child.

Tommy Giovannelli, now aged 10, had been expelled from one school by six and was being threatened with a second expulsion at eight. His father, Nick, said Tommy was unable to concentrate, would throw tantrums for no apparent reason and would smash objects in the classroom.

It was by chance that Mr. Giovannelli heard about the hyperactive children's group and from them learned of the test. Tommy was found to have zinc levels 55 per cent below normal.

Within weeks of giving him supplements and removing all additives from his diet, his behaviour had changed beyond recognition.

At Baverstock School in Birmingham, six children have now been given the test. Barbara Parkes, a specialist in teaching dyslexics, said: "I am convinced that the behaviour of large numbers of young offenders is due to poor diet."

Andrew, a pupil a Baverstock School, could not concentrate, would beat people up and would talk manically throughout lessons. When the test result came back it showed he had a very high imbalance.

Now Andrew has shown a dramatic improvement. "He even asked for extra work for the school holidays," Mrs Parkes said."

Minerals and Metals vs ADHD: Our Comments

A few years ago I ran hair sample tests on 10 ADD kids to see what I'd find.

According to the norms of the lab that did the testing, none of the kids were within the normal ranges. However, none of the kids were alike. Some were high in heavy metals, some were not. Some were low in certain minerals, some were not. I could not discern patterns.

However, there was one thing that did stick out.

Every child whose parents smoked was very high in Cadmium (a toxic heavy metal) levels. Is this a cause for alarm? Yes!

Heavy metals such as mercury, lead, cadmium, and nickel are very toxic to the human body (toxic to any form of life) and can pass the blood- brain barrier and be terrible neuro-toxins.

No child, especially not ADHD children, should be exposed to these toxic metals.

And yet without knowing, most parents have these toxic metals actually placed into the mouths of our children in the form of dental work: mercury-amalgam fillings are 50% mercury, and also contain copper and nickel; and braces for our children are often made of these toxic heavy metals as well.

These are bad for all of us.

And as time goes on I am becoming more and convinced that nutritional supplements can play a significant role in the treatment of ADHD and other behavior disorders.

No, I don't think that they are the ONLY or the BEST treatment options. I believe that many elements need to be looked at in treatment, including Moral Training, Parenting Classes, Family Counseling, Medications, EEG Biofeedback Training, as well as Nutritional Interventions.


This book section: What is ADHD?

Douglas Cowan, Psy.D., M.S. is a licensed Marriage and Family Therapist in Tehachapi, CA who has been a counselor to children, teens, and adults helping them to overcome ADHD, find relief for depression or anxiety, and solve other problems in life since 1989. He served on the medical advisory board to the company that makes Attend and Extress from 1997 through 2011, and he is the Editor of the ADHD Information Library online resource at http://newideas.net/. His weekly ADHD Newsletter goes out to 9,500 families. Visit his website at http://DouglasCowan.me for more information on achieving greater health, personal growth, Christ-centered spirituality, stress management, parenting skills, ADHD, working out the stresses of being a care-giver to elderly parents and also being a parent to teenagers, or finding greater meaning in retirement years, Dr. Cowan can be a valuable resource to you.

Counselor counseling Tehachapi for ADHD, depression, anxiety, and more.

Douglas Cowan, Psy.D., MFT
27400 Oakflat Dr.
Tehachapi, CA 93561
(661) 972-5953

Share it now