Russell Barkley ADHD

Russell Alan Barkley is a clinical psychologist and author of books on attention deficit hyperactivity disorder. He is also a clinical professor of psychiatry at VCU Medical Center.

What does Barkley have to say about attention deficit hyperactivity disorder (ADHD)?

"Our findings reveal that ADHD is far more than a neurodevelopmental condition; it's a major public health concern," Dr. Barkley explains. "When we looked at the long-term health effects of ADHD, we discovered that it had a negative impact on every area of quality of life and longevity."

What Causes Attention Deficit Hyperactivity Disorder?

Russell A. Barkley, Ph.D. Russell A. Barkley, Ph.D. Russell A. Barkley, Ph

On the subject of etiologies of disease, one could write entire book chapters.

ADHD, as I did for the fifth edition of my textbook, ADHD Handbook, published in 2015.

for Diagnosis and Treatment (Guilford Press, New York), It's been the subject of entire works, including as

Joel Nigg, Ph.D., stated more than a decade ago in 2006 (What

What are the causes of ADHD? There have been almost 1,000 research published.

per year in scientific papers on ADHD. A significant portion of the population

The focus of these journal papers is on the disorder's etiology, therefore the field is broad.

is fast progressing toward a better understanding of causal mechanisms.

I'll go over these causes quickly here, but I'll also touch on two more issues.

Is Attention Deficit Hyperactivity Disorder (ADHD) a Myth? Is it a case of misdiagnosis or overdiagnosis?

Simply said, the etiology of ADHD is complicated and can be caused by a variety of factors.

causes. All of the significant ones thus far have been in the field of neurology.

and genetics (biological causality), despite the fact that there is little proof that social factors play a role.

The disorder cannot be explained solely by external circumstances. However, there are some exceptions.

proof that a few social factors play a role (chronic stress, global adversity)

may interact with a person's genetic susceptibility to the condition, exacerbating it

it. However, the majority of such environmental factors linked to ADHD are

Other biohazards, such as brain trauma, are included in the category of biohazards.

damage to the nervous system, lead poisoning, or other toxic exposures, such as

Premature births, alcohol consumption throughout pregnancy, and so on. I'll do it.

I'll go over those in more detail later.

Here's a straightforward explanation of the complicated causality of


ADHD is at the extreme end of a spectrum of disorders.

natural human features that are significantly connected, similar to

intelligence. These are inattention (particularly) in this circumstance.

Distractibility, inability to pay attention for long periods of time), inhibition, and

executive performance (self-regulation). When the degree of deficiency is high,

(symptoms) in these characteristics reach a degree where they cause

Individual harm (impairment in important sectors of living activities, etc.)

When these inadequacies become a problem (increased risk of injury or death), they become a problem.

disorder. As a result, the definition of a "disease" begins when there is a risk of harm or death.

In such cases of dimensional features, impairment begins - in other words, the

The environment retaliates, causing negative repercussions.

Individuals who are at the very bottom of these trait dimensions (or

higher end of the symptom spectrum).

What causes the human population's differences in these traits?

especially when it comes to extremes? Without a doubt, the most significant

Genetics is a factor. Variation in ADHD has been shown in numerous research.

Variation in human genes (about 55%) determines the majority of phenotypes.

90 percent of the variance, with an average of 75-80 percent). This is it.

Is significantly greater than the genetic contribution to human height.

Is the genetic contribution to IQ or human personality traits greater than the genetic contribution to IQ or human personality traits, or is

Genetics makes twice as much of a difference in mental illnesses like schizophrenia.

Only one other gene contributes as much to sadness or anxiety, and only one other gene contributes as much to depression or anxiety.

a few other psychiatric conditions, such as autism spectrum disorder and schizophrenia

bipolar disorder is a mental illness that affects people. As a result, heredity plays a role in ADHD.

significant in explaining the majority of the heterogeneity in patients with ADHD


These genetic impacts can manifest themselves in a variety of ways. The first is created by

inheritance. The ADHD genes are passed down to the child from their parents.

parents. Scientists have discovered between 25-45 genes that are linked to

Based on genome-wide scanning, ADHD symptoms have been identified. As a result, the chaos exists.

Multiple genes contribute to the illness, making it polygenic.

Each one is likely to pose a minor risk, but a combination of them poses a significant risk.

increases the likelihood of disorder The more risk genes you have, the higher your risk.

The higher the chance of manifesting the disorder's phenotype.

Despite the fact that we all have these gene types, they are known to differ.

persons in terms of the number of copies they receive (the length of the document)

tandem repeats, or the complete gene complex), or

polymorphisms. While we all carry the DRD4 or DAT1 gene,

For example, these genes can be found in several copies side by side.

Along a chromosome, (tandem repeats) are found. The majority of persons have 3-5.

duplications of the DRD4 gene People with ADHD are more likely to have.

duplications of these genes, such as 7 or more DRD4 repeats

gene. The length of the gene is affected by the number of copies it has.

It produces a protein that changes the way the brain works. In

In certain situations, an additional copy of the gene is placed on the chromosome.

chromosome Others may have a section of the gene that is defective, while others may have a section of the gene that is defective.

has been removed from the list

All of the genes for ADHD that we've discovered so far are expressed in

Not only in terms of neurochemical expression, such as dopamine, but also in terms of cognitive function.

sensitivity to norepinephrine and norepinephrine absorption into nerve cells following

release, but mainly in the migration and termination of nerve cells

How they might be pruned later in specific brain regions

even how many synapses they establish in linking neurons

up to and including other nerve cells Alternatively, the issue could be with the architecture.

the inside of the cell It could, for example, have an excessive number of reuptakes.

At the terminals or pre-synapse, there are transporters. These behave as if they were miniatures.

The neurotransmitter is absorbed back into the neuron via vacuum pumps.

After being released into the gap between nerves, a cell moves too quickly.

cellular (the synapse). Perhaps there are too many alpha-2 ports along the way.

It's the axon or cell trunk that allows too much "noise" to damage the quality of the signal.

That axon is carrying a nerve signal. It could also have a membrane.

at a less sensitive post-synapse to a neurotransmitter, such as

as well as dopamine In that situation, the average amount of dopamine released is

It is not enough for a nerve cell to "fire" if it is freed and joins to the next nerve cell.

stimulate the next nerve cell that is "insensitive." Alternatively, the gene could simply be defective.

influence on the nerve cell's ability to be fostered or function thereafter.

Another piece of evidence regarding ADHD heredity is the fact that it runs in families.

In a sense, relatives of children with ADHD are at a higher risk.

for having the illness - the closer the genetic link to

The greater the risk to the relative, the more ADHD the youngster has. As a result, 25-35 percent

parents of ADHD children 25-50 percent of children and adults with ADHD are children.

Siblings of ADHD children have ADHD, and 70-92 percent of identical twins have ADHD.

The disorder is seen in twins of a child with ADHD.

The disorder's expression can also be influenced by genetics in the second approach.

as a result of the emergence of new (de novo) mutations in the genes

Thosegenes in the child's genome that aren't found in the parents'. We

This could explain for at least 10% of ADHD cases, especially if they are severe.

are there new cases in a family where there is no elevated risk among the members?

the family members In the gametes (egg and sperm), new mutations might occur.

sperm-producing cells) based on the amount of time a person has been alive.

We are constantly exposed to mutation-causing substances, hence we are alive.

X-ray devices, environmental pollutants, and the sun's beams are just a few examples.

etc. We become more mutation-causing agents as we live longer.

The more we're exposed to something, the more mutations we're likely to develop in these cells.

gametes. The gene mutations are subsequently passed on to the next generation.

despite the fact that they are not present in the DNA of the child

parent, as seen by their blood cells. This is brand new.

About 25% of all new mutations are now known to be caused by mutations.

For example, there is likely to be an increase in cases of autistic spectrum disorder.

The likelihood of occurrence increases with the age of the parents, particularly in men.

over 30 years old, but also in moms We believe the same thing is going on.

As well as in ADHD.