Autism Spectrum Disorder

What Is Autism Spectrum Disorder?

What is ASD? Autism is a complex developmental disorder that can cause social, communication, and behavior challenges in the roughly 1 in every 68 children it affects. Learn more the signs of ASD in children and adults here.

What is ASD? A girl with autism plays with her father
What is ASD? A girl with autism plays with her father

What Is Autism Spectrum Disorder (ASD)?

  • Autism Spectrum Disorder (ASD) is a complex developmental disorder that affects ability to communicate and interact socially.
  • It is characterized by repetitive behaviors or language, and restricted interests.
  • ASD occurs on a continuum of severity from mild challenges to difficulty with everyday life.

Autism Spectrum Disorder (ASD) is a complex neurobiological disorder that is characterized by difficulty communicating verbally and relating socially to others, alongside a need to engage in repetitive behaviors or language. Some common early signs noted by parents are delayed speech, restricted interests, not responding when called by name, and avoiding eye contact.

ASD occurs on a broad continuum of severity. Some people with ASD experience only mild challenges. For others, the condition interferes with everyday life.

Approximately 1 in 68 children in the U.S. has ASD, which is about 4.5 times more common among boys than girls. One study found that children with ADHD are up to 20 times more likely to exhibit some signs to ASD than are their neurotypical peers. Early detection and treatment using a combination of educational and behavioral interventions, medication, and alternative therapies is critical to the social, academic, and professional success of people with ASD.

Read on to learn more about ASD and how to treat it with therapy and medication. Consult with a physician if you recognize the symptoms below in yourself or your child.

[Self-Test: Could I Have Autism Spectrum Disorder?]

What Are The Three Main Characteristics or Symptoms of Autism?

Autism is generally characterized by social and communication difficulties and by repetitive behaviors. More severe forms of ASD are often diagnosed in the first two years of a child’s life, but less severe forms may be diagnosed later, when developmental delays become apparent. Symptoms occur in three main areas, and may vary as children grow:

  • Social interactions
  • Verbal and nonverbal communication
  • Repetitive or ritualistic behaviors

People with autism can be high functioning and have only mild challenges, or they can have more severe symptoms, like impaired spoken language, that interfere with everyday life. No two people with ASD will have the same symptoms manifested in the same way.

Children with autism don’t intuitively grasp the social world, and their social skills may lag behind those of other children. This often becomes evident during play and communication. They have limited imaginative play skills, take things literally, and may not use gestures to communicate. As they get older, they may learn these skills though their autism diagnosis remains intact.

ASD is typically a lifelong condition, though a small percentage of children outgrow the diagnosis. Therapy, even started late in life, may have major benefits in addressing behaviors such as:

  • Difficulty interpreting what others are thinking or feeling
  • Trouble interpreting facial expressions, body language, or social cues
  • Difficulty regulating emotion
  • Trouble keeping up a conversation
  • Inflection that does not reflect feelings

Adults can exhibit repetitive behaviors and have specific, extreme interests in particular topics like sports teams or science. These interests may border on obsessions.

[Self-Test: Is My Child On the Autism Spectrum?]

What Are The 3 Types of Autism?

Until recently, the Centers for Disease Control recognized three main types of ASD:

  • Asperger Syndrome: Previously used to describe children with average cognitive skills who struggled with social and communication impairments of any severity. This was a milder, higher-functioning form of autism that included intense, unusual interests. It is now sometimes referred to as Social Communication Disorder.
  • Autistic Disorder/Autism: Previously used to describe children with more severe impairments who struggled with social and communication delays, early language delays, and repetitive or obsessive behaviors.
  • Pervasive developmental disorder, not otherwise specified (PDD-NOS): Previously used as a catch-all term for social-communication concerns that didn’t fit neatly into either of the other two boxes above. It implied milder symptoms.

The term “Asperger Syndrome” was dropped from the latest version of the Diagnostic and Statistical Manual of Mental Disorders. These diagnostic guidelines were updated to eliminate the divisions above and to introduce the autism “spectrum,” along with a patient may mild, moderate, or severe symptoms.

Many parents and physicians continue to use the old labels, which is important to consider when researching the condition. For more information on the label changes, read: “Moving Past the ‘Asperger Syndrome’ Label.”

How Are Autism and ADHD Related?

ASD can be a stand-alone disorder, or it may coexist with other disorders. One study found that children with ADHD are up to 20 times more likely to exhibit some signs of ASD than are their neurotypical peers1. Autism is generally characterized by social and communication difficulties, and by repetitive behaviors. ADHD is marked by inattention, hyperactivity, and impulsivity, though social challenges are often part of the ADHD equation as well.

To differentiate ADHD from ASD, many clinicians work to determine whether weak social skills derive from an executive-function impairment or from a broken or missing developmental building block. For example, is a child having difficulty taking turns because he simply wants to play next, or because he doesn’t grasp the nature of the game?

It’s important to separate difficulties that mimic autism from actual symptoms. Early detection and treatment of the correct condition are crucial. A professional who is familiar with ASD, ADHD, and other similar neurological conditions can use clinical skill and experience to find the true source of a patient’s challenges.

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1 Dennis Thompson. “More Links Seen Between Autism, ADHD.” HealthDay. (2013). Web. (

What Is the Main Cause of ASD?

Research studies show that childhood vaccinations do not cause autism.

However, the exact cause of ASD remains unknown. Most physicians agree it is a result of abnormalities in brain structure or function, observed when comparing the MRIs of children with autism to those of neurotypical children1. Research teams are studying a number of theories, including hereditary risk, the impact of genetics, and other medical problems.

Some studies have shown that a child with an older sibling with ASD is at a higher risk for an ASD diagnosis2. Other research suggests that certain environmental factors, such as iron deficiency in the womb or while breast feeding3 or maternal infections/medications during the pre- and perinatal phase4 have a deep impact on the occurrence of ASD. Another study suggests specific gene mutations could influence the development of ASD5.

The “Magical World Theory” proposes that people with ASD struggle to put into context the events they experience or observe6. In other words, they cannot determine what happened before an event to cause it, or make predictions about what might occur as a result. The researchers behind this theory posit that this deficiency taxes the brain, making it constantly overwhelmed with analyzing a seemingly chaotic environment. Because of this ceaseless need for observation and problem solving, people with ASD experience heightened anxiety due to endless uncertainty and hypersensitivity. These scientists believe that the autistic brain cannot become “used to” certain touches, facial expressions, sights, and sounds in the same way a neurotypical brain can. It cannot prioritize the stimuli, and thus it is constantly hypervigilant, and overly sensitive to too-tight clothing or too-loud sounds.

ASD is a condition in which people do not learn social skills within typical developmental milestones7. This can present as limited interaction with the people around them, difficulty interpreting facial expressions or tone of voice, or limited language. Children with ASD may have delayed language skills, be completely nonverbal, or have unusual conversation habits like repeating phrases. Others will speak at length in an advanced vocabulary about a favorite topic, but have limited skills with taking turns in conversations. Repetitive behaviors can range from a movement like hand-flapping, made over and over, to becoming preoccupied with having objects in a certain order or a strict routine.

Autism may manifest as other worrisome behaviors – like emotional outbursts or self-injurious behaviors like head banging or hair pulling. These could appear as self-soothing mechanisms used when a person with ASD is overwhelmed, or they could be an obsessive tic. The behaviors’ cause is unknown, and they are not always present with an ASD diagnosis. Treatment tailored to severity of symptoms can help alleviate difficulties and make it easier for people with ASD to learn social skills, communicate, and control repetitive behaviors.

ASD commonly co-occurs with other medical conditions including ADHD, gastrointestinal (GI) disorders, anxiety, fragile X syndrome, sleep dysfunction, pica and seizure disorders like epilepsy. Often, symptoms overlap with other conditions, making ASD tricky to diagnose.

[ADHD Directory: Find Specialists or Clinics Near You]

1“About Autism – Causes.” ADDitude magazine. (2015). Web. (

2Janice Rodden. “New Study: Vaccines Don’t Cause Autism.” Autism Society. (2015). Web. (

3Devon Frye. “Prenatal Iron Intake Linked to Autism.” ADDitude magazine. (2014). Web. (

4Wayne Kalyn. “Prenatal Iron Intake Linked to Autism.” ADDitude magazine. (2014). Web. (

5Janice Rodden. “New Link Found Between Gene Mutation, Working Memory, and Autism.” ADDitude magazine. (2015). Web. (

6Janice Rodden. “Living in an Unpredictable World: Researching the Root of Autism.” ADDitude magazine. (2014). Web. (

7Mark Bertin. “Autism and ADHD: The Complete Playbook for Social Challenges.” ADDitude magazine. (2015). Web. (

How and When Is Autism Diagnosed?

If you recognize the signs of ASD in you or your child, don’t waste time in locating a knowledgeable physician to perform an evaluation. Early intervention therapy is one of the most effective treatments for ASD.

No lab test can diagnose ASD; symptoms are extremely broad and unique to each individual. Because some symptoms overlap with ADHD, diagnosing and separating the disorders can be difficult. The protocol for diagnosing ASD requires an autism-specific behavior evaluation conducted by a qualified professional like a developmental pediatrician, psychiatrist, or neurologist.

First, a physician will screen for symptoms that indicate ASD, using a diagnostic tool. The Modified Checklist of Autism in Toddlers (M-CHAT) and its series of informative questions can indicate if a child’s behaviors merit evaluation. Then, the physician will likely observe you or your child and talk to you about developmental, social interaction, and communication skills. Additional diagnostic tools include the Screening Tool for Autism in Two-Year-Olds (STAT) and the Social Communication Questionnaire (SCQ) for children four years of age and older1. For high-functioning autism, the common screeners are the Autism Spectrum Screening Questionnaire (ASSQ), the Childhood Asperger Syndrome Test (CAST), and the Australian Scale for Asperger’s Syndrome1.

If the screening tools indicate ASD, a diagnostic evaluation involving a psychologist, neurologist, speech therapists, and other professionals who are experts in ASD will begin. Typically, it will involve genetic testing, neurologic exams, and interviews with caregivers that may use the Autism Diagnosis Interview-Revised (ADI-R) or the Autism Diagnostic Observation Schedule (ADOS-G)1. The physician should also evaluate your child for other conditions like hearing disorders, which could be causing similar symptoms.

Most insurance companies, and virtually all public schools, require a written evaluation by a specialist before they will provide, or pay for, the services that many autistic children need. Even when a professional ventures an opinion, he will often hedge by saying, “The child is quirky and exhibits some behaviors that are somewhat consistent with a diagnosis of a high-functioning autism.” This kind of talk is frustrating, but it’s sometimes unavoidable. Evaluating the child at a later date often clarifies things. A child who is receiving the help he needs may not require a diagnosis, but many patients find relief in knowing the medical reason for their struggles.

1National Institute of Mental Health. “How Autism is Diagnosed.” PsychCentral. (2013). Web. (

What Are the Treatment Options for Autism Spectrum Disorder (ASD)?

There are three main types of treatment for ASD:

  • Educational and behavioral interventions
  • Medication
  • Alternative therapies

Most clinicians prefer to begin with non-medical therapies to manage the symptoms that hinder social and academic success and lead to a turbulent home life. Behavioral therapy and early-intervention therapy both help children learn new skills to better interpret the world with the challenges of ASD.

When these interventions aren’t sufficient, medication may help. A class of medicines called atypical antipsychotics often helps with motor restlessness, repetitive behaviors, and sleep disturbances in children with autism. Typical prescriptions include aripiprazole (Abilify), quetiapine fumarate (Seroquel), and risperidone (Risperdal, which is the only one approved by the FDA for treating behaviors associated with autism.

Many people with chronic conditions like ASD supplement traditional therapies and medications with alternative treatments, though their effectiveness is not well researched. Parents of children with ASD and adults with the condition should consult with a physician before taking any supplements or trying any alternative treatment methods.

[Read More: What Autism Spectrum Disorder Looks Like in Adults]

Autism Spectrum Disorder At a Glance

Comorbidity with ADHD · Nearly one third of children with ASD also meet diagnostic criteria for ADHD.
· Children with ADHD are 20 times more likely to exhibit some signs of Autism Spectrum Disorder than neurotypical peers.
Suggestive Symptoms · Delayed speech and learning gestures
· Tendency to avoid eye contact
· Difficulty imitating the actions of others
· Preference for solitary play
· Failure to respond to social cues
· Failure to seek comfort when upset
·  Trouble understanding the perspective of others
· Trouble creating sentences
· Tendency to repeat words or phrases
· Arranging objects in a particular order
· Repetitive behaviors like twirling or rocking
· Wiggling fingers or flapping hands
·In adults, lack of understanding of facial expressions, body language, or social cues; difficulty interpreting what others are thinking or feeling; inflection that does not reflect feelings; difficulty regulating emotion
Professional to See Diagnosis and treatment should be conducted by a qualified developmental and behavioral pediatrician, child and adolecent psychiatrist, or neurologist.
Treatments & Medications · Behavioral therapy for children coupled with parent-training
· Atypical neuroleptics including aripiprazole (Abilify), quetiapine fumarate (Seroquel), and risperidone (Risperdal)
Recommended Resources ·
· Autism Spectrum Disorderby Chantal Sicile-Kira
· Early Intervention and Autismby James Ball, Ed.D.
· Ten Things Every Child with Autism Wishes You Knewby Ellen Notbohm
· The Autistic Brain, by Temple Grandin
· The Reason I Jump, by Naoki Higashida
· Life, Animated, by Ron Suskind