Why Autism Diagnoses Have Increased

The prevalence of autism spectrum disorders in the U.S. is currently estimated at 1 in 36 children. Factors contributing to this increase include heightened awareness and changes in diagnostic criteria. The article stresses the importance of accurate identification and early screening, which may lead to more effective care and support for individuals with autism.

updated December 22, 2025

This information is current as of the date of original publication or update. It may have changed by the time you read this. I invite you to fact-check what you read here.

Please do not use this information for diagnosis or treatment purposes. Before making health decisions, discuss with your physician or other qualified healthcare provider.

Like other physicians and families of people with autism, I puzzle over the increased number of children and adults diagnosed with autism. And most all of us have theories about why we now believe 1 in 36 children have autism spectrum disorders.

People point out that “when they were children” they never knew of anyone with autism. Some are convinced that the increase of autism followed the introduction of the measles-mumps-rubella vaccine, MMR.

Others implicate genetics, environmental toxins, diet, and intrauterine brain trauma. In 2025, then Secretary of HHS, Robert Kennedy Jr. announced that the “cause” of autism is Tylenol (generic acetaminophen), which President Donald Trump announced in a press conference. No definitive proof was provided and later the claim was softened.

Autism Prevalence in the United States Explained

“The bulk of the increase (in autism rates) stems from a growing awareness of autism and changes to the condition’s diagnostic criteria.”

This article (updated in 2020) was published in Spectrum whose commitment is “to provide accurate and objective coverage of autism research.” Spectrum is funded by the Simons Foundation Autism Research Initiative. Senior News Writer Jessica Wright, Ph.D. in biological sciences from Stanford University, wrote the report. (Scientific American also published the article by permission.)

A diverse group of children smiling as they stand closely together in a circle staring downward. Text overlay reads, “cdc dot gov slash Autism.”
This #AutismAcceptanceMonth, @CDC_NCBDDD encourages awareness, inclusion, and connection to support services and one another. Learn more about our work in understanding #Autism in children:

Identifying Autism

Let’s consider some terminology. Prevalence is an estimate of how common a disease or condition is in a particular population of people at any given time.

So the prevalence of autism in children would be

the number of children identified as autistic at any given time

divided by the total number of children alive at that time.

The currently accepted rate of autism is 1 in 36 children.

Autism prevalence depends on children being correctly identified as autistic. At any given time, some autistic children may not be identified, and some may be  incorrectly identified.

We do not have any totally objective tests available for autism yet. There is no blood test, scan, culture, imaging study, DNA test, or monitor to definitely conclude that autism is or is not present.

The definition of and criteria for autism have changed substantially since “infantile autism” was first identified by Leo Kanner over 70 years ago. Since 1980, the diagnosis is based on applying the criteria outlined in the Diagnostic and Statistical Manual of Mental Disorders (DSM).

In the most recent version, DSM-5, released in 2013, autism, Asperger syndrome, and pervasive developmental disorder, formerly separate, are now a single diagnosis.

Autism Spectrum Disorder is characterized by

  • Persistent deficits in social communication and social interaction across multiple contexts
  • Restricted, repetitive patterns of behavior, interests, or activities
  • Symptoms must be present in the early developmental period (But may not yet be fully expressed or may be modified by learned behavior in later life)
  • Symptoms cause clinically significant impairment in social, occupational, or other important areas of current functioning.
  • These disturbances are not better explained by intellectual disability (intellectual developmental disorder) or global developmental delay.

Autism spectrum disorder DSM-5 diagnostic criteria: Full text

When the diagnostic criteria for other diseases we diagnose and manage changes, the prevalence also changed. Examples include diabetes, high cholesterol, high blood pressure, migraine, obesity, depression, even some cancers. So autism is not unique in this regard.

The currently accepted rate of autism, 1 in 36, comes from the Autism and Developmental Disabilities Monitoring Network , established by the CDC in 2000. Children are identified by reviewing health and school records of 8-year-olds in selected counties. So possibly some children get missed, and some are assigned incorrectly.

Point of Reference: IDEA

Another major milestone in autism awareness occurred in 1991 when the U.S. Department of Education ruled that autistic children qualify for special education services. This ruling encouraged parents of children with developmental and intellectual disabilities to secure accurate diagnoses, to qualify for services they otherwise might not have access to.

AAP recommends screening

Since 2006, the American Academy of Pediatrics has recommended routine screening of all children for autism at 18 and 24 months old. Many physicians, psychologists, and therapists believe early intervention improves these children’s chances to do well intellectually and socially.

If we could go back and review records of children 10, 20, or 30 years ago, and apply current diagnostic criteria, would we find less autism than we do today? Perhaps. But such records would likely reflect the understanding of autism at the time, so might still fail to recognize autism, even when present by today’s standards.

The apparent increased number of children with autism seems alarming-some call it an epidemic. It may represent our increased awareness, recognition, and knowledge about this disorder. And while this increase should raise concern, it can lead to increased research, treatment options, and more effective care for autistic persons.

Also on this Blog

Aching Joy- a book review

Jason Hague’s memoir “Aching Joy” explores faith, fatherhood, and autism through the lens of his son’s diagnosis. Despite initial denial and shaken faith, Hague finds solace in trusting a higher power. The book is a powerful journey through grief, hope, and ultimately, faith in the face of unexpected challenges.

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a book cover- Aching Joy

A Different Way of Seeing Autism- a book review

“Uniquely Human: A Different Way of Seeing Autism” by Barry M. Prizant, PhD, CCC-SLP offers insights into understanding and living with autism. The book promotes a person-centered approach, emphasizing the importance of engaging, building self-esteem, and fostering joyful experiences for individuals with autism. Dr. Prizant advocates for working with their strengths rather than focusing on…

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UNIQUELY HUMAN- A DIFFERENT WAY OF SEEING AUTISM, a book by Barry Prizant, Ph.D.

Exploring the HEART of Health

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Dr. Aletha

The Vaccine Friendly Plan – a book review

The Vaccine-Friendly Plan by Paul Thomas and Jennifer Margulis emphasizes informed decision-making regarding childhood vaccinations. While promoting a pro-vaccine stance, the authors advocate for considering individual health needs and offer guidance on pregnancy and child development. Their approach includes discussing environmental toxins and providing strategies to support immune health in children.

updated December 22, 2025

This information is current as of the date of original publication or update. It may have changed by the time you read this. I invite you to fact-check what you read here.

Please do not use this information for diagnosis or treatment purposes. Before making health decisions, discuss with your physician or other qualified healthcare provider.

The Vaccine-Friendly Plan

by Paul Thomas, M.D., a pediatrician  and

Jennifer Margulis, Ph. a science journalist.

In 1961,  my mother and I went to my school on a Sunday afternoon to receive the newly released oral polio vaccine. She along with other parents eagerly sought a way to prevent a dreaded disease that had the potential to cripple or even kill their children.

In medical school I learned about diphtheria, a painful throat infection due to a bacteria, Corynebacterium diphtheriae. Once a common cause of severe illness and death, a vaccine had rendered it rare. I saw no cases of diphtheria in medical school, nor have I since.

As a young physician I welcomed the introduction of the H.Flu vaccine (Haemophilus influenzae bacteria, not the virus) in 1985. At that time, any infant or toddler with a fever was a potential victim of meningitis due to H.Flu, which could be deadly or leave the child with neurological damage.

Similarly, the Hepatitis B vaccine made healthcare a less risky occupation; Hepatitis B is a blood-borne infection contracted from contact with infected blood.

VACCINE-PREVENTABLE DISEASES
FROM THE CDC, JANUARY 2016-

So, I was first surprised, then puzzled, then alarmed at the number of parents who reject vaccination for their children, and adults who decline immunizations for themselves. Some people now fear the vaccines more than the diseases they prevent. must consider this to help people stay well instead of treating them when sick.

I was intrigued when I heard of a book, by a physician that seems to promote a compromise-

The Vaccine-Friendly Plan

The Vaccine-Friendly Plan is published by Ballantine Books,  2016

It is based on his pediatric practice, Integrative Pediatrics,  as well as their extensively noted references. The book’s subtitle summarizes the contents accurately-

“Dr. Paul’s Safe and Effective Approach to Immunity and Health- from Pregnancy through your Child’s Teen Years.”

The book discusses pregnancy, infant, and child care in general, not just vaccination, although that is a major emphasis. There is a chapter about pregnancy and for each stage of child development through adolescence.

The first chapter discusses a popular health topic now- toxins. (As an aside, I don’t know when we started calling poisons  “toxins”) . This should grab your attention-

“Toxins, Toxins, Toxins: Raising Healthy Children in a Poisoned World”.

Anything can be “toxic” if misused, overused, or abused but they concentrate on these toxins in particular- acetaminophen, aluminum, aspartame, fluoride, methanol, mercury, and what they call endocrine disruptors(this includes pesticides).  They state “environmental toxins are likely contributing to the autism epidemic” as well as other neurodevelopmental and mental disorders in children.

 They base their conclusion on an extensive list of review articles from the medical and scientific that support their view and from Dr. Paul’s medical practice of 11,000 children who he calls “among the healthiest in the world.” While I suspect families who are already health-conscious tend to select a physician who is health-oriented, this claim sounds impressive.

I agree with some of the advice the authors offer. For example this advice for pregnancy is hard to argue with-

  • Eat a whole foods, organic, non-GMO diet 
  • Skip the soda
  • Drink filtered water
  • Minimize stress
  • Get treatment for addiction
  • Join a support group

But in addition, they recommend declining all vaccinations during pregnancy, certainly not mainstream medicine advice.

A later chapter also offers sound advice:

“ The Best Ways to Support your Child’s Immune System” 

  • Breast feed
  • Enjoy cuddling
  • Laugh a lot
  • Relax often
  • Rock your body
  • Stay hydrated
  • Eat a variety of foods
  • Maintain social connection
  • Read
  • Get Dirty
  • Be cautious but not afraid
  • Choose vaccines based on real science, your family’s needs and common sense
  • Sleep enough
  • Trust your children
  • Trust yourself

He offers an interesting list  Ten Questions to Ask When Looking for a Pediatrician (which I assume would apply if you use a family physician for your child’s care).

As a physician, I have never liked the idea of being “interviewed” by a potential patient; I  want a relationship with patients, not a job. But I think pediatricians routinely offer “get-acquainted” visits so you may find it helpful.

Some of the questions seem more appropriate to explore  in a long-term relationship with a physician, not quick answers in a short visit, like “What would you like me to know in order to keep my family healthy?”

An appendix compares the CDC immunization schedule of 1983 to the current 2016 version, illustrating  many more vaccines and doses are now recommended.

Of course the list is longer since several new vaccines have been developed in the past 30 years and the CDC recommends those considered necessary for the public health. Most areas of medical care have changed dramatically in the past 30 years, we have a lot more of everything-drugs, procedures, etc- so this should not be a surprise.

vaccines
CDC Immunization Schedule-

Also in the appendix is Dr. Paul’s Vaccine Plan at a Glance, which is a much abbreviated version of the CDC recommendations. The plan is offered free at his web site . (There is also a “store” on the website offering an assortment of vitamins, minerals, probiotics, and melatonin.)

The authors describe themselves as “pro-vaccine”, have received vaccines themselves and vaccinated their children. But they also believe that physicians and parents should have a choice and make informed decisions about immunization and other procedures. 

Universal vaccination is recommended , but there are individual circumstances where the routine schedule might need to be altered due to a child’s particular medical circumstance, but not for some vague concern that vaccination might not be “safe”. Neither is infectious disease.

If you are a parent who has deferred vaccination for your children,  please read this book soon.

Also, read another review of this book by  Vincent Iannelli, MD , a pediatrician and Fellow of the American Academy of Pediatrics.
Sonia Shah, a science journalist, also wrote about vaccination in her book
Pandemic – Tracking contagions from cholera, to Ebola, and beyond

Pandemic- a book review

If you like history, current events, medical science, or just want to be more knowledgeable about why we should be concerned about infections , antibiotic resistance and vaccine phobia, you should read this book.

Keep reading
another post on this topic

Vital questions you should ask about immunization

This coronavirus pandemic is serious. We don’t yet have a vaccine or effective treatments. To protect ourselves, our familes, and our entire communities we should all be practicing social distancing and other hygiene measures as we wait for a safe, effective vaccine and treatments.

Keep reading

Exploring the HEART of Health

I’d love for you to follow this blog. I share information and inspiration to help you transform challenges into opportunities for learning and growth.

Add your name to the subscribe box to be notified of new posts by email. Click the link to read the post and browse other content. It’s that simple. No spam.

I enjoy seeing who is new to Watercress Words. When you subscribe, I will visit your blog or website. Thanks and see you next time.

Dr. Aletha