Autism Fast Facts

An estimated 3.5 million Americans are living with autism.

In the 1970s, autism was a relatively rare disorder. Today, the developmental disorder strikes 1 in 59 children born in the U.S. In the 1970s, autism affected 1 in 2000 children.

A third of children with an autism spectrum disorder suffer from seizures.

Scientists are confident that vaccines do not cause autism.

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Most children were still being diagnosed after age 4, though autism can be reliably diagnosed as early as age 2. 

What is Autism Spectrum Disorder?

Autism is a brain-based developmental disorder. People with ASD have difficulty communicating and interacting with others. Children diagnosed with ASD typically are unresponsive to social cues, appear remote or preoccupied, and have difficulty expressing abstract feelings. Autistic children often seem oblivious to other people’s emotions.

Individuals with autism typically don’t initiate or sustain conversations except on topics of interest to them. Up to a third of children with autism don’t speak at all. Nearly a third have an intellectual disability. However, significant language delays are rare in people with the high-functioning form of ASD.

Autism was classified as a disorder in 1943 by Dr. Leo Kanner, a psychiatrist at Johns Hopkins University School of Medicine. Today, the umbrella term of ASD includes autism, the disorder formerly known as Asperger’s syndrome, Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS), and Childhood Disintegrative Disorder (regressive autism).

The high-functioning form of the disorder, formerly known as “Asperger’s syndrome,” is now classified as an autism spectrum disorder. Pervasive Developmental Disorder (PDD) is a brain-based developmental disorder that interferes with the perception of social cues and sensory information. Children with the condition suffer from bewildering sensory overload that impairs brain function.

In recent years, the diagnosis of autism spectrum disorders (ASD) has increased significantly in the United States. It’s not clear whether the rise in diagnosed cases of ASD stems from an actual increase in the prevalence of the disorders or increased awareness of their symptoms.

Symptoms and Effects of ASD

Autism is a spectrum disorder, meaning that not everyone experiences it in the same way. There is wide variability in the symptoms and behaviors of people with a condition on the autism spectrum.

Symptoms of ASD can include:

  • Problems with verbal and nonverbal communication, including spoken language, gestures, facial expressions, tone of voice, and eye contact
  • Expressing and recognizing emotions in self and others
  • Anxiety in social situations
  • Sensitivity to sensory overstimulation
  • Repetitive or ritualistic behaviors
  • Intense interest in narrow subjects
  • Need for routines or rules to follow

Other characteristics of ASD may include:

  • Autism is associated with repetitive behavior patterns, such as arm flapping and rocking from side to side. Difficulties appear early in development, generally by age three.
  • Up to 40% of people with autism also suffer from anxiety.
  • People with autism often struggle to understand social nuances.
  • People with autism often suffer from gastrointestinal (GI) problems, seizures, sleep disturbances, attention-deficit/hyperactivity disorder (ADHD), and phobias.
  • Despite these challenges, some individuals with ASD show unique strengths in problem-solving and attention to detail.
  • Children with the high-functioning form of ASD sometimes display extraordinary abilities with memory, music, or mathematics.

What Causes Autism Spectrum Disorder?

The causes of autism have not yet been discovered. Studies have identified risk factors that seem to be associated with ASD, but much of the research into its causes has been inconclusive. The following factors may increase the risk of autism, but none of them is, by any means, a reliable predictor of the disorder:

  • Male gender. Boys are four times more likely than girls to develop ASD.
  • A mother or father who is 35 or older at the time of conception.
  • Pregnancy and birth complications, including extreme prematurity (earlier than 26 weeks), low birth weight, and multiple births (twins, triplets, etc.).
  • Pregnancies spaced less than one year apart.
  • Chronic stress during pregnancy.
  • Vitamin D deficiency during pregnancy.
  • Too much or too little folic acid (also called folate or vitamin B). Pregnant women should talk to their doctor before taking vitamin supplements.
  • Viral infections during pregnancy. Exposure of the mother to rubella (German measles) or a cytomegalovirus (CMV) infection during pregnancy may increase the risk.
  • Use of certain drugs, such as valproic acid, thalidomide, and misoprostol, during pregnancy.
  • Environmental triggers and exposure to toxic chemicals such as bisphenol-A (BPA).

Is Autism Spectrum Disorder Hereditary?

Autism arises from a complex interplay of genes and the environment. Genetics plays a role in ASD, but scientists still don’t know precisely how risk for the disorder is inherited. While some genes and gene variations are known to raise susceptibility to the condition, the genes’ presence doesn’t necessarily mean that an individual will develop ASD. Even when one identical twin has autism, the other twin has only a 60 percent chance of receiving the same diagnosis.

Although environmental factors are almost certainly partly to blame for the development of autism, a recent study has suggested that as much as 80% of the disorder’s risk comes from genetics.

How is Autism Spectrum Disorder Detected?

There are currently no tests to detect autism. Genetic testing is available for people with a strong family history of ASD, although the presence of high-risk genes does not mean that an individual has autism. Genetic counselors can help people make decisions about the need for testing.

ASD usually appears early in life, causing delays in learning to talk, play, and interact. Generally, the earlier a child is diagnosed, the better.

In many cases, the first signs of autism appear in infancy, with developmental signs occurring as the child fails to achieve milestones.

Signs of ASD in infancy include:

  • Lack of smiling or eye contact by six months
  • Little interaction or expression of emotion by nine months
  • Lack of pointing, demonstrating, reaching, or waving by 12 months
  • Few or no spoken words by 16 months

Signs of ASD at later ages include:

  • Loss of communication skills
  • Problems with eye contact
  • Avoidance of social interaction
  • Problems expressing or recognizing emotion
  • Delays in spoken language development
  • Repetitive movements or repetitive language
  • Sensory sensitivity
  • Excessive need for routine
  • Intense, narrow interests

How is Autism Spectrum Disorder Diagnosed?

No lab test, blood work, or imaging exams are used to diagnose ASD. Pediatricians usually do an assessment at a child’s 18- and 24-month checkups to look for the disorder’s developmental signs.

Doctors observe the child’s behavior and talk to parents. If concerns arise, an autism specialist may be recommended to evaluate a child’s behavior and development to make a diagnosis.

If ASD is suspected, healthcare professionals will work through a checklist of questions to pursue a diagnosis. Some of these questions might include:

  • Are the child’s behaviors odd or repetitive?
  • Does the child have trouble making eye contact?
  • Does the child interact with other people?
  • Does the child respond to someone’s voice?
  • Is the child sensitive to light, noise, or temperature?
  • Does the child have sleep or digestive problems?
  • Does the child seem irritable or angry?


How is Autism Spectrum Disorder Treated?

Current approaches to the treatment of ASD focus on managing behavioral symptoms and helping with social skills. The most successful Interventions are in the areas of occupational therapy, speech, and language therapy.

So far, no drugs have been approved by the FDA to address the core symptoms of ASD. Risperidone and aripiprazole may be used to treat irritability associated with ASD. Some other medications, such as selective serotonin reuptake inhibitors (SSRIs), are sometimes used in an “off-label” way (meaning to treat symptoms other than the ones for which the drugs are approved) to treat symptoms of ASD.

A wide range of behavioral therapies and psychotherapy approaches have proven to be effective at treating ASD. Commonly used treatments include:

  • Behavioral management therapy
  • Cognitive behavior therapy (CBT)
  • Educational and school-based therapies
  • Joint attention therapy
  • Nutritional therapy
  • Occupational therapy
  • Parent-mediated therapy
  • Physical therapy
  • Social skills training
  • Speech-language therapy

How Does Autism Spectrum Disorder Progress?

The social, developmental, behavioral, and emotional symptoms of ASD can lead, over time, to a long list of physical, mental, and social health problems. Some mental health issues often co-occur with ASD, and some physical complications can arise from long-term behavioral aspects of ASD.

Long-term complications can include:

  • Social isolation
  • School or work difficulties
  • Financial problems
  • Inability to live independently
  • Depression or anxiety
  • Obsessive-compulsive disorder
  • Eating disorders
  • Gastrointestinal problems
  • Muscular or skeletal problems (from unusual posture, gait, or repetitive movements)
  • Epilepsy
  • Dental problems (from lack of hygiene, jaw clenching, or teeth grinding)
  • Allergies or skin problems
  • Injuries (or death) caused by lack of awareness of safety concerns

How is Autism Spectrum Disorder Prevented?

There is no known way to prevent autism or to cure it when it occurs. The causes of the disorder are unknown, and avoiding speculative risk factors has not proven effective at reducing ASD occurrence.

The best course of action is early detection and prompt treatment of autism when it is diagnosed. The earlier a child is diagnosed with the disorder, the better the chance therapeutic intervention will help to control symptoms and minimize their impact down the road.

Autism Spectrum Disorder Caregiver Tips

Some of the ways you can help your child cope with autism include:

  • Educate yourself. The more you know, the better you’ll be able to help your child. That means you should learn as much as you can about autism, but it also means you should know about your child’s individual experience with the disorder. Each child is different, with different sensitivities, triggers, challenges, and strengths. You can best support your child when you’re an expert on his or her autism.
  • Know the difference between science and pseudo-science. Misinformation surrounding autism abounds, and you need to know how to recognize it. Rely on authoritative sources, and don’t be swayed by people who offer dubious causes or miraculous cures for the disorder.
  • Provide a safe, comforting environment. Ensure your child has a space that’s free of the things that make him or her uncomfortable.
  • Provide consistency. Stick to routines, schedules, rules, and reliable ways of doing things.
  • Be an advocate for your child. Only you know what’s best for your child, and it’s up to you to be sure that caregivers, teachers, family members, and everyone else knows how to best support your family.

The majority of people with autism also suffer from other brain and mental health-related conditions, a situation called co-morbidity. Here are a few of the disorders commonly associated with autism:

  • Depression and anxiety are commonly comorbid with autism. More than 80 percent of people with autism are estimated to have some form of anxiety disorder.
  • Autism spectrum disorder and ADHD have many of the same symptoms, and many children may be diagnosed with both disorders.
  • One study found that as many as 17 percent of people with autism also have obsessive-compulsive disorder (OCD).
  • More than a quarter of people with autism may also have bipolar disorder.

Between 25 and 40 percent of people with autism also have epilepsy, a rate more than ten times higher than in the general population.

Autism Spectrum Disorder Brain Science

Research is ongoing in many different directions to increase our knowledge of autism, its causes, its identification, and its effective treatment. Current areas of research include:

  • Researchers are looking at the relationship between autism and related disorders such as tuberous sclerosis complex, Fragile X Syndrome, Phelan-McDermid syndrome, and Rett syndrome. The hope is that learning about these disorders can help scientists understand how autism develops and predict when it may occur.
  • Studies of the development of nerve cells in the brain aim to discover how abnormal communication between these cells may cause autism.
  • Imaging studies are looking for differences in brain activity between people with autism and people without the disorder. An understanding of these differences could lead to therapies or medications that could improve symptoms of ASD.

Autism Spectrum Disorder Research

Scientists are working on several research projects to expand on what is known about Autism. The research will improve knowledge about the factors that increase the risk for Autism and the causes and best treatments and aid people living with Autism and their caregivers.

We are currently gathering the information required to support projects such as Study of Neuroimaging Biomarkers of Social Cognition Deficits in Adolescents (Age 13-17) With Autism Spectrum Disorder and Effects of Gabapentin, Brain Mechanisms for Language Processing in Adolescents With Autism Spectrum Disorder (BSL), and Pivotal Response Treatment for Children With Autism Spectrum Disorders (PRT).

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For you or a loved one to be diagnosed with a brain or mental health-related illness or disorder is overwhelming, and leads to a quest for support and answers to important questions. UBA has built a safe, caring and compassionate community for you to share your journey, connect with others in similar situations, learn about breakthroughs, and to simply find comfort.

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