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Excerpt from Chapter Two

The Etiology of Chronic Childhood Illness

There are many names for today’s chronic childhood illnesses.  These names are autism, ADHD, allergies, asthma, multiple sclerosis, depression, bipolar disorder and many other labels that can be found in the DSM-IV (standard diagnostic manual).  From a pharmaceutical and clinical management perspective these are meaningful terms because there are certain pharmacological and behavior modification techniques for each of these “diseases” that can help improve some symptoms.  However, these labels become somewhat inadequate when considering how to prevent and cure these illnesses.  No one seems to know what causes any of these illnesses outside of some correlations to genetics, but these findings are not fully developed.  Chronic illnesses like autism and ADHD are a real problem for all conventional medical clinicians.  Typically, there is little they can offer their patients outside of symptom management.

To practitioners of functional medicine, autism, asthma, multiple sclerosis and many other illnesses are not so much “diseases” as they are observable manifestations of human bodies with fundamental biochemical and physiological imbalances.  Conventional western medicine describes ADHD as a genetically-based brain dysfunction that results in inattention, hyperactivity, and impulsivity.  This way of understanding ADHD tells us to look in the brain or at a genetic profile for answers as to what causes ADHD.  The functional medicine approach is different.

Through established scientific research and laboratory testing, functional medicine recognizes that ADHD is associated with imbalances in the levels of micronutrients (or vitamins and minerals used by the body for basic functions), neurotransmitters (necessary brain chemicals), and excesses of heavy metals in the body, among other dysregulated processes. Through diagnostic laboratory testing, clinicians can evaluate a particular patient’s imbalances and look for what might have contributed to these imbalances.  For instance, deficiencies in micronutrients in the body (such as zinc, selenium, magnesium) can be explained by looking at the diet and how effectively or ineffectively the body assimilates these nutrients into the gastrointestinal tract.

Similarly, mood and behavior problems can be assessed by looking at the levels of neurotransmitters (such as dopamine or serotonin) circulating in the blood.  Disorders associated with a deficiency in serotonin, a critical brain chemical required for mood stability, can be explained by looking at how effectively the body produces serotonin, which, interestingly, is produced in the gastrointestinal tract.  In fact, 95% of your body’s serotonin is manufactured in the duodenum (part of the small intestines)![i] For a patient with depression or ADHD (both conditions marked by altered levels of neurotransmitters or “brain chemicals”), one cannot begin to understand the origin of these “diseases” without first looking at the health of the gastrointestinal tract.  Many of the imbalances in the body’s brain chemicals actually originate in the “gut.”

The “gut,” or gastrointestinal tract, simply refers to the long hollow tube that stretches from the tip of your tongue to your anus.   Since the bulk of neurotransmitters are produced in the gut, it would seem logical that a physician would examine the gut health of a patient with a mood disorder.  Yet few physicians, and even fewer psychiatrists, examine gut health when diagnosing and treating this sort of illness. This completely ignores a biological system that is likely to play a critical role in the onset of illness.

What functional medicine offers that conventional western medicine does not, is the ability and the potential to determine etiology of illnesses that were previously understood only as “chronic,” “incurable,” or worse, “genetic.”  If you understand the root cause(s) of illness, then the chances of treating, curing and preventing illness increase exponentially.  For example, millions upon millions of dollars have been spent, and hundreds of thousands of research hours have been invested into the search for the cause of autism.  Most of this time and money has been spent looking at the brain and genetics.  Is there no greater puzzle in the medical world today than the etiology of autism?  Functional medicine is beginning to uncover some of the root causes of autism (and there are many).  Applied functional medicine has reversed autism in thousands of patients across the country.  Many of these children have completely lost their autism diagnoses to be considered “neurotypical,” indistinguishable from their “normal” peers.  These same protocols have been applied to children suffering from ADHD, allergies and asthma, and they have also recovered from their illnesses.

What, then, causes autism?  What causes asthma, ADHD, allergies, juvenile diabetes, bipolar disorder, depression, and the many other chronic illnesses plaguing our children today?  The answers to these questions are complicated and vary significantly from patient to patient, but there are some underlying mechanisms and environmental factors that are present in various combinations in virtually all chronic illnesses in children.  Particular changes in American life over the last century have precipitated an increased likelihood of children developing chronic illness, but the changes that have been seen over the last few decades are accelerating this likelihood at an unprecedented rate.

Root Causes:  The Perfect Storm

The epidemic of chronic childhood illness in America is the product of  “a perfect storm” of environmental factors including:  the overuse of medications, poor diet and nutrition, excessive hygiene, indoor sedentary lifestyles, excessive or improperly administered vaccination, and continuous exposure to a panoply of environmental toxins.  To a degree, genetics play a role in the development of illness for particular children, but genetically-based explanations do not explain the unprecedented and widespread biological dysfunctions among children today.  There are no epidemics of genetic illnesses, only environmentally-derived illnesses.  There are simply too many sick children today to substantiate the theory that genetics cause their illnesses.

An Explanation of Common Biological Dysfunctions at the Root of Chronic Illness

Instead of looking at chronic childhood illnesses as distinct entities, let us look at common underlying biological and physiological imbalances that are present in most of these illnesses.  One of the first clues that points to common underlying biological dysfunctions in all of these illnesses is the fact that most children present with a primary diagnosis (such as asthma), but they also present with a variety of comorbidities.  Comorbidity is a term used to describe the presence of a secondary, and often less severe, chronic disease in a patient.  Many children with ADHD, for instance, are saddled with other conditions such as, seasonal allergies, eczema, or obsessive-compulsive disorder.  It is very common for children with asthma to also have food allergies and eczema.  Children with autism typically carry the worst comorbidity load, suffering from gastrointestinal illnesses such as colitis, reflux, and chronic diarrhea, but they also tend to have allergies (food and respiratory), and other neurological comorbidities such as anxiety or ADHD.  The fact that many of the symptoms of chronic illness in children overlap leads us to ask if there are common underlying biological dysfunctions.

In kids with chronic illnesses some of the most basic biological systems and functions are “broken” or operate improperly.  One of the common underlying biological dysfunctions found in virtually all children with chronic illnesses is something known as “immune dysregulation.”  This simply means that their immune systems are not functioning properly.  This phenomenon has been observed in the clinical setting, but it has also been demonstrated through laboratory analysis.

It is well known that the etiology of allergies and asthma is tied to immune dysregulation.  However, what is less well known, at least outside the medical community, is the fact that almost all of the chronic illnesses in children today are in some way related to immune dysregulation.  In recent years, medical researchers have established immune dysregulation as one of the principle suspects in the etiology of autism.[ii] Other illnesses are also believed to be rooted in immune dysregulation.  Juvenile diabetes, long believed to be a genetic disorder is now understood as an autoimmune disorder.[iii] Autoimmunity (when the immune system attacks a body’s own cells/tissues) is no longer an obscure term used to discuss illnesses such as multiple sclerosis or lupus, but rather a vast umbrella that covers hundreds of illnesses as seemingly distant as rheumatoid arthritis and celiac disease.

Immune dysregulation is ubiquitous in American children today, and it goes beyond just those who are “sick.”  Many children who might be considered healthy by an untrained eye have more subtle signs of immune dysregulation like chronic constipation, moderate behavioral problems, reflux, chronic sinusitis, recurrent ear infections, or a particular susceptibility to colds and flu.  America is experiencing a historic epidemic of immune dysregulation in its children and researchers are finally beginning to figure out why.

Despite the medical establishment’s most desperate desires to find the holy grail of disease in our genes, there is no one “autism gene” or “ADHD gene.”  Genetic information is important for understanding the etiology of these chronic illnesses, as it can provide us with information on an individual’s degree of susceptibility to particular environmental factors.   But the genetic susceptibilities may not be meaningful if we do not understand how these susceptibilities work in concert with environmental triggers and influences.  It is an extraordinarily complicated web of specific environmental factors that have precipitated this recent trend of chronic illness in American children.  Simply put, everyday we send our children out into a world that is saturated with toxins and immunological challenges, but many of our children are, what could only be described as, immunocompromised.  In other words, the immune systems of many children have been altered and made dysfunctional by an assortment of environmental factors.  The origin, as well as the clinical consequence, of each child’s immune dysregulation varies.  This is why it is so difficult to pin down the etiology of chronic childhood illnesses:  the specific root causes of each child’s illness vary according to his or her particular environmental exposures and unique genetic make up.


[i] Michael Camilleri, “Serotonin in the gastrointestinal tract,” Current Opinion in Endocrinology, Diabetes and Obesity 16, no. 1 (February 2009): 53-59.

[ii] IN Pessah et al., “Immunologic and neurdevelopmental susceptibilities of autism,” Neurotoxicology 29, no. 3 (May 2008): 532-45; PH Patterson,  “Immune involvement in schizophrenia and autism:  Etiology, pathology and animal models,” Behavioural Brain Research 24 (Dec 2008).

[iii] Roland Tisch et al., “Dysregulation of T cell peripheral tolerance in type 1 diabetes,” Advances in Immunology 100 (2008): 125-149.