The Latest on Autism

Everywhere you turn, there's another report about autism. It can be so confusing -- and frightening.

What is autism anyway? Is autism a hidden epidemic, as we are sometimes led to believe? And is autism linked to childhood vaccines? The answers may surprise you.

Autism is one of a group of developmental disorders that fall under the heading of autism spectrum disorders or ASD. These conditions involve delays in the development of many basic skills. The most notable delay with autism is the ability to socialize or form relationships with others. With autism, there's also a delay in the ability to communicate and to use imagination (including fantasy play).

The exact cause of autism is not known, but research has pointed to several possible factors, including genetics (heredity), metabolic and neurological factors, certain types of infections, and problems during pregnancy and at birth. A supposed connection between childhood vaccines and autism has been well discredited by several wide-ranging studies.

Although it affects four times as many boys as girls, autism knows no racial, ethnic, or social boundaries. Family income, lifestyle, or educational levels do not affect a child's chance of having autism.

While most people with autism will always have some trouble relating to others, early diagnosis and treatment have helped more and more people with autism to live independently as adults.

What Are the Symptoms of Autism?

Some children show symptoms of autism spectrum disorders from birth. Others seem to develop normally at first, only to slip suddenly into symptoms when they are 18 to 36 months old (although this is a much smaller group).

Children with autism can display a wide range of symptoms, which can vary in severity from mild to disabling. Autism symptoms typically appear before a child is 3 years old and last throughout a lifetime. General symptoms that may be present to some degree in a child with autism include:

  • Difficulty with verbal communication, including problems using and understanding language
  • Inability to participate in a conversation, even when the child has the ability to speak
  • Difficulty with nonverbal communication, such as gestures and facial expressions
  • Difficulty with social interaction, including relating to people and to his or her surroundings
  • Little or no eye contact, including sometimes the child acting as if he or she can’t see who or what is in front of the child, despite normal visual testing
  • Unresponsive to verbal cues; acts as if deaf, although hearing tests in normal range
  • Inability to make friends; prefers to play alone
  • Unusual ways of playing with toys and other objects, such as only lining them up a certain way
  • Difficulty adjusting to changes in routine or familiar surroundings, or an unreasonable insistence on following routines in detail
  • Repetitive body movements, or patterns of behavior, such as hand flapping, spinning, and head banging
  • Preoccupation with unusual objects or parts of objects

People with a form of autism called savantism have exceptional skills in specific areas such as music, art, and numbers. People with savantism are able to perform these skills without lessons or practice.


What Causes Autism Spectrum Disorders?

There is no single cause for ASD. Recent studies strongly suggest that some people have a genetic predisposition to autism, meaning that a susceptibility to develop the condition may be passed on from parents to children. Researchers are looking for clues about which genes contribute to this increased vulnerability, and many genes have been identified. However, abnormal genes are not the only cause.

In some children, environmental factors may also play a role. Studies of people with autism have found abnormalities in several regions of the brain, which suggest that autism results from a disruption of early brain development during fetal development. Some studies have shown abnormal brain shapes and structures in children with autism.

Other autism theories suggest:

  • The body's immune system may inappropriately produce antibodies that attack the brains of children, causing autism. This theory has still not been scientifically proved.
  • Abnormalities in brain structures cause autistic behavior.
  • Children with autism have abnormal timing of the growth of their brains. Early in childhood, the brains of autistic children grow faster and larger than those of normal children. Later, when normal children's brains get bigger and better organized, the brains of kids with autism grow more slowly.
  • Possible problems during pregnancy or delivery -- such as viral infections, metabolic imbalances, and exposure to environmental chemicals -- cause autistic behavior.

The Link Between Childhood Vaccines and Autism Spectrum Disorders

There has been ongoing controversy surrounding certain childhood vaccines and their relationship to ASD.

Many studies have looked at whether there is a link between autism and vaccines. To date, there is no known evidence that any vaccine can cause autism. A suspected link between the measles, mumps, rubella (MMR) vaccine and autism spectrum disorders has been suggested by some parents of children with autism. Typically, symptoms of autism are first noted by parents as their child begins to have difficulty with delays in speaking after age 1. Around this same time, the MMR vaccine is first given to children, but autism symptoms that arise around the same time are, scientists say, an unrelated chance occurrence. A study from Great Britain trying to prove this “link between autism and the MMR” was discovered to have been falsified by the lead author, who has subsequently lost his license to practice medicine.


A report debunking the link between the MMR vaccine and the development of autism spectrum disorder showed no significant increase in autism cases after doctors began using the MMR vaccine in 1988. It also showed that children in the study showed signs of autism spectrum disorder at the same ages, regardless of when they were vaccinated. Finally, the study found that by age 2, vaccination coverage among children with autism was nearly equal to that for children of the same age who did not have autism.

Parents have also questioned whether mercury-containing thimerosal (used as a preservative in vaccines) might cause autism. Today, with the exception of some influenza vaccines, vaccines used in the United States to protect preschool-aged children contain reduced or no thimerosal as a preservative. (Influenza vaccine is currently available both with thimerosal as a preservative and preservative-free.) According to the CDC, there is no convincing scientific evidence of harm caused by the low doses of thimerosal in vaccines, except for minor reactions like redness and swelling at the injection site. More importantly, studies have not found a link between thimerosal-containing vaccines and autism. In fact, a multi-nation study showed an increase in autism over a period of ten years after thimerosal was removed from vaccines.

Because the exact cause of autism is not known, parents may continue to have concerns, despite the evidence. In these cases, parents should be aware of the risks of serious disease in children who are not vaccinated. In some areas, outbreaks of these dangerous diseases have occurred in people who have not been immunized.

Understanding the Ruling on Autism-Like Symptoms and Vaccines

In a recent controversy, a Georgia girl was entitled to compensation after developing autism-like symptoms after she received five childhood vaccines in 2000. But what does this decision mean to your child and to other children?

It's important to note that the government has not said that childhood vaccines actually cause autism. Rather, the Division of Vaccine Injury Compensation (DVIC) at the Department of Health and Human Services agreed there is a possibility that the vaccines aggravated an underlying mitochondrial disorder in this young girl. The mitochondrial disorder manifested as a regressive neurological disease with some symptoms of autism spectrum disorder. There is a small relationship between mitochondrial disorders and autism, which is now being actively researched.


Understandably, many parents are worried about the risks that are thought to accompany vaccinations. Ever since the first vaccines were developed, there have been risks. Most vaccine side effects are mild, and severe ones are extremely rare. But the use of vaccines in children has essentially eradicated a number of major childhood diseases that kill. When parents fail to vaccinate their children, the risk of serious -- even deadly -- disease epidemics extends beyond them and their families to their neighborhoods and communities. Failure to vaccinate lays the foundation for new epidemics that could result in serious harm to your child. For instance, a decline in vaccination rates in some European countries has led to fatal outbreaks of measles. Deadly outbreaks of pertussis have also been seen in the U.S. and Great Britain because of an irrational fear to immunize.

In short, while some advocacy groups continue to take issue with immunizations, CDC officials maintain that this ruling should not be seen as indicating a risk from vaccines for all children. In a statement, the American Academy of Pediatrics reinforced its dedication to the health of all children and urges parents to fully immunize their children.

What Difficulties Does a Child With Autism Face?

Children with autism have trouble communicating. They have trouble understanding what other people think and feel. This makes it very hard for them to express themselves either with words or through gestures, facial expressions, and touch.

An autistic child who is very sensitive may be greatly troubled -- sometimes even pained -- by sounds, touches, smells, or sights that seem normal to others.

Autistic children may have repeated body movements such as rocking or hand flapping. They may have unusual responses to people, attachments to objects, resistance to change in their routines, or aggressive or self-injurious behavior. At times, they may seem not to notice people, objects, or activities in their surroundings.

Some people with autism are mentally challenged, although most people with an autism spectrum disorder have normal or even above-average intelligence. In contrast to being cognitively impaired, which is characterized by relatively even skill development, people with autism show uneven skill development. Those with autism may have problems in certain areas, especially the ability to communicate and relate to others. But they may have unusually developed skills in other areas, such as drawing, creating music, solving math problems, or memorizing facts. For this reason, they may test higher -- perhaps even in the average or above-average range -- on nonverbal intelligence tests.


How Is Autism Diagnosed?

The American Academy of Pediatrics (AAP) recommends screening children for autism as part of the 18-month and 24-month well-patient visits in addition to the developmental screening performed at all healthy child wellness visits. This policy helps health professionals identify signs of autism early. Developmental screening tools, such as the Ages and Stages Questionnaire or the Modified Checklist for Autism in Toddlers (M-CHAT), can help assess behavior.

If a health professional discovers the following obvious signs of developmental delays, the child should immediately be referred for a full evaluation:

  • No babbling, pointing, or other gestures by 12 months
  • No single words by 16 months
  • No two-word spontaneous phrases by 24 months, with the exception of repeated phrases
  • Any loss of any language or social skills at any age

If your primary care provider does not have specific training or experience in developmental problems, he or she may refer your child to a specialist, usually a developmental-behavioral pediatrician, neurologist, psychiatrist, speech therapist, or child psychiatrist, for additional testing. If there are no obvious signs of developmental delays or any unusual indications from the screening tests, most infants and children do not need further evaluation until the next regular checkup.

However, children who have a sibling with autism should continue to be closely monitored because they are at increased risk for autism and other developmental problems. In addition to the evaluations at well-child visits, these children should undergo testing for language delays, learning problems, poor socialization skills, and any symptoms that might suggest they have anxiety or depression.

When socialization, learning, or behavior problems develop in a person at any time or at any age, he or she should also be evaluated. Most experts believe that if a parent has a "hunch" the child may have autism, they should insist that the child be evaluated. Often, parents know when a child is not connecting with them, whereas a doctor may miss these cues.

The Different Types of Autism

Conditions that fall under the autism spectrum disorder classification include:

  • Autistic disorder. This is what most people think of when they hear the word "autism." It refers to problems with social interactions, communication, and imaginative play in children younger than age 3.
  • Asperger's syndrome. Children with Asperger's syndrome have some traits of autism, especially weak social skills and a preference for sameness and routine. But unlike those with autism, children with Asperger's syndrome usually start to talk around age 2 (the age at which speech normally develops). They have normal to above-normal intelligence.
  • Childhood disintegrative disorder. This condition resembles autism. These children develop normally for at least two years and then lose some or most of their communication and social skills.

Rett syndrome was previously classified under ASD but has since been found to be linked to genetics instead. However, many children with Rett also have autism. Known to occur primarily in girls, children with Rett syndrome almost always occurs in girls. They begin to develop normally. Then they begin to lose start losing their communication and social skills. Head growth slows during the first months of life and a loss of purposeful hand movements occurs. Muscle movement is startling and mental retardation is typical.


How Is Autism Treated?

Symptoms and behaviors of autism can combine in many ways and vary in severity. In addition, individual symptoms and behaviors often change over time. For these reasons, treatment strategies are tailored to individual needs and available family resources.

While there is no cure for autism, early intervention and treatment may allow for relatively normal development in the child and reduce undesirable behaviors. Children with autism generally benefit most from a highly structured environment and the use of routines. Treatment for autism may include a combination of the following:

  • Special education: Education is structured to meet the child's unique educational needs.
  • Behavior modification: This includes strategies for supporting positive behavior and decreasing problem behaviors.
  • Speech, physical, or occupational therapy: These therapies are designed to increase the child's functional abilities.
  • Social skills training: This training helps children learn to interact and read verbal and non verbal cues more appropriately.
  • Medication: There are no drugs approved to treat autism, but medications may be used to treat specific symptoms, such as anxiety, depression, hyperactivity, and obsessive-compulsive behaviors or behaviors that may result in injury.

What Autism Research Is Being Done?

The National Institute of Neurological Disorders and Stroke, part of the National Institutes of Health, is studying brain abnormalities that may cause autism and is looking for genes that may increase the risk of autism. Researchers also are investigating possible biologic markers present at birth that can identify infants at risk for developing autism. Other studies are examining how different brain regions develop and function in relation to each other and how alterations in these relationships may result in the signs and symptoms of autism. Researchers hope these studies will provide new clues about how autism develops and how brain abnormalities affect behavior.

Autism cannot be prevented or cured. But early diagnosis and intervention is critical and may help to maximize a child's ability to speak, learn, and function.

It is very important that all children see a pediatrician or family physician regularly so that any signs of autism can be detected early. The earlier treatment is started, the more effective it can be.

WebMD Medical Reference Reviewed by Smitha Bhandari, MD on May 31, 2016



Montes, G. Pediatrics, May 2007.

National Institute of Neurological Disorders and Stroke: "Autism Fact Sheet."

National Mental Health Information Center: "Children and Adolescents with Autism."  

National Institute of Child Health and Human Development: "Autism Overview: What We Know"  and "Autism Research at the NICHD." 

National Institutes of Health: "Gene linked to autism in families with more than one affected child."

CDC: "Vaccines and Autism: Important Conclusions from the Institute of Medicine" and "National Immunization Program: MMR vaccine and autism."

WebMD Medical Reference: "Understanding Autism: The Basics;"  "Autism Symptoms, Causes, Treatment and More;"  "Children with Autism: Coping Skills for Parents;" and "Dietary and Other Interventions."

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