Autism Spectrum Disorder Basics

by Child Mind Institute, Inc.


Autism spectrum disorder (ASD) is a developmental disorder that is marked by two unusual kinds of behaviors: deficits in communication and social interaction, and restricted or repetitive behaviors. This guide outlines how to identify ASD symptoms in children and best practices for diagnosis and treatment of kids on the spectrum.


Autism: What Is It?

Autism spectrum disorder (ASD) is a condition that impacts a child’s development in two core areas: the first is social communication and social interaction, and the second is restricted, repetitive patterns of behavior and interests. Although a child has ASD from birth, it may not come to attention until social demands exceed a child’s limitations.

In the psychiatric community, thinking about autism has changed, as reflected in the new DSM-5 guidelines. What had been considered a set of distinct conditions described as pervasive developmental disorders — autism, Asperger’s disorder, childhood disintegrative disorder (CDD), and pervasive developmental disorder not otherwise specified (PDD-NOS) — are now considered one disorder that presents along a spectrum of symptoms and behaviors of varying severity.

1 in 59 children are diagnosed with ASD. Boys are diagnosed with ASD around 3 to 4 times more often than girls.

Autism: What to Look For

Children with autism spectrum disorder are characterized by a combination of two unusual kinds of behaviors: deficits in communication and social skills, and restricted or repetitive behaviors. These symptoms may vary greatly in severity.

Social communication and social interaction: Signs of social deficits you might notice in a developing child include aversion to displays of affection like cuddling and hugging and a preference for solitary play. In younger kids, say under 3, failure to respond to their own name is a red flag, as is disinterest in giving, sharing, or showing objects of interest. In older children, warning signs include difficulty carrying on a reciprocal conversation, lack of eye contact, and difficulty using and reading body language. These children may have difficulty recognizing others’ emotions, responding appropriately to different social situations, and understanding social relationships.

Some children with autism don’t talk; others talk in a stilted, “robotic” tone, or in an exaggerated singsong. A child with autism may also repeat certain phrases without appearing to understand their significance, or possess what experts call “non-functional knowledge”—information he can recite, but not use to solve problems or carry on a conversation. Young kids with autism don’t point at objects of interest, don’t make eye contact, and don’t use gestures to communicate a need or describe something. As kids with autism age and acquire language, their tone or pattern of speech can be odd; some have a habit of reversing pronouns—a youngster asking his mom for water might say “You want water” instead of “I want water.” High-functioning children with autism may monopolize conversations while showing little capacity for reciprocity, or understanding what the other party wants or feels.

Restricted or repetitive behaviors: Key behavioral signs include the performance of repetitive actions and rituals, and fixation on minute details to the point of distraction. Children with autism can be upset by the slightest change in daily routine. In young kids, signs of autism include ordering toys instead of playing with them. In older children, the repetitive behavior can manifest as a consuming interest in a specific topic or object.

The new DSM-5 behavioral criteria include what are often called sensory processing problems. Many children with autism are unusually sensitive to sounds, lights, textures or smells. They may be overwhelmed by too much sensory input, or be disturbed and uncomfortable because of a lack of sensory input, which they may try to get by bumping into things, and excessively touching and smelling things.

Autism: Risk Factors

Risk factors include low birth weight, fetal exposure to valproate, and parental age. Boys are more likely to be diagnosed with autism spectrum disorder.

Some people have concerns that autism spectrum disorder is caused by vaccinations that children receive. However, studies have shown that there is no link between receiving vaccines and developing ASD. Learn more about vaccines and autism from the CDC.

Autism: Diagnosis

For diagnosis of autism spectrum disorder, a child must display symptoms in two core areas: social communication and social interaction, and restrictive, repetitive patterns of behavior, interests, and activities. The symptoms must be impairing, and must be present in the early developmental period—they are typically recognized in a child’s second year—but they may not be fully manifest until a child is older and the social demands exceed his abilities. ASD can be diagnosed as early as 24 months.

In the category of social communication and social interaction, a clinician will look for persistent deficits in social reciprocity, such as back-and-forth conversation and sharing of interests; nonverbal communication, including body language and gestures; and difficulty developing, understanding, and participating in age-appropriate relationships.

In the category of restrictive or repetitive patterns of behavior, a clinician will look for two of the following: stereotyped movements, actions or use of speech, inflexible insistence on routines and rituals, fixated and intense interests, and sensory problems, either from too much sensory input or two little.

According to the new criteria, these symptoms must be significantly impairing, and a clinician will specify the severity of each of the symptoms on a three-tiered scale that reflects the amount of support a child would need—requiring support, substantial support, or very substantial support—to function successfully.

Given that children with autism also frequently have cognitive impairment (now called intellectual development disorder), children should not be diagnosed with autism unless their social communication deficits are greater than would be explained by their cognitive impairment.

If a child has impairment in social communication and social interaction but doesn’t have restrictive and repetitive behaviors, he is more likely to be diagnosed with a new disorder called social communication disorder.

Autism: Treatment

A structured educational program and tailored behavioral therapy have been shown to be very beneficial to children with autism.

Psychotherapeutic: One effective intervention is a psychotherapeutic regimen called applied behavior analysis. This therapy seeks to maximize the child’s learning and development by systematically encouraging desired social and communication behaviors, actively teaching ways of interaction other children learn intuitively in childhood. Another approach, dubbed “developmentally-based intervention,” seeks to educate and engage with a child using the subjects, words, and stimuli appropriate to the developmental stages they have in effect been excluded from, modeling the typical progression for an atypical child. As autism and autism spectrum disorders manifest differently in every child, other therapies include occupational, physical, and speech-language.

Pharmacological: There are no drugs that target the core symptoms of autism, but medications are often prescribed to help with problems that often occur alongside the disorder, such as depression, anxiety, and hyperactivity.

Alternative: It should be noted that many alternative treatments and even “cures” have been proposed for autism spectrum disorder. None of these alternative treatments—chelation, diets, supplements, facilitated communication—have any reliable scientific evidence behind them. Some, particularly chelation—an attempt to remove heavy metals from the body via chemical injections—can be very dangerous. It’s important that parents who choose to pursue these therapies should do so in close consultation with a qualified physician.

Autism: Other Disorders

Children with autism have certain other medical problems at a rate far above average. Epilepsy afflicts almost a third of children diagnosed with autism once they reach adulthood. Sleep disorders, allergies, and digestive problems are commonly seen, as are tic disorders like Tourette’s. Kids with autism are also more likely than others to be cognitively impaired.

Dyslexia Diagnosis & Treatment By Mayo Clinic Staff

Childhood apraxia of speech by Mayo Clinic Staff

What Are Some of the Causes of Aggression in Children? By Raul Silva, MD

How to Calm a Child with Autism By Lisa Jo Rudy

How Autistic Meltdowns Differ from Ordinary Temper Tantrums By Lisa Jo Rudy 

5 Simple Ways to Make Life Easier for Your Sensitive Kid By Lindsey Biel

Understanding Generalized Anxiety Disorder in Children By Keath Low

Sensory Integration by  Autism Research Institute

ADHD or Autism? By WebMD

Learning Disabilities: What Parents Need To Know by American Academy of Pediatrics

Anxiety disorders by Mayo Clinic Staff