Autism Signs & Symptoms

Learn about autism spectrum disorder

Autism spectrum disorder is a type of neurodevelopmental disorder. Individuals who develop autism spectrum disorder may experience difficulties with communication and social interactions, as well as limitations or other challenges related to behaviors, interests, sensory processing, and activity levels.

Indications that a person is experiencing an autism spectrum disorder are typically present in early childhood. Children who have autism will often fail to meet appropriate developmental milestones. For example, they may experience delayed acquisition of language skills, and may not demonstrate age-appropriate social interest, play patterns, or behavioral progress.

The signs, symptoms, and effects of autism spectrum disorder can vary considerably from person to person. In past years, variances in the nature and severity of symptoms were addressed via terms such as childhood autism, high-functioning autism, atypical autism, Kanner’s autism, and Asperger’s syndrome.

However, with the publication of the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), the diagnosis of autism spectrum disorder replaced these other terms. Clinicians who diagnose a child with autism may now use specifiers such as “autism spectrum disorder with accompanying language impairment” or “autism spectrum disorder without accompanying intellectual impairment” to provide a more detailed description of how an individual is impacted by autism spectrum disorder.

Autism spectrum disorder statistics

The following statistics about autism spectrum disorder among children in the United States were reported by the U.S. Centers for Disease Control and Prevention (CDC) and the National Institute of Mental Health (NIMH):

• Research indicates that about one in every 59 children in the United States has autism spectrum disorder.
• From 2000-2014, the estimated prevalence of autism spectrum disorder among U.S. children increased from 0.6% to 1.69% of the population.
• About 7% of boys and 0.7% of girls in the United States have autism spectrum disorder.
• About 44% of children with autism spectrum disorder have IQ scores that qualify as average or above average.
• About 85% of children who were eventually diagnosed with autism spectrum disorder had displayed evidence of developmental concerns by the time they were three years old.

Causes and risk factors for autism spectrum disorder

Experts have not identified a single definitive cause of autism spectrum disorder. However, considerable research has identified a variety of genetic and environmental factors that may raise a person’s risk for developing autism spectrum disorder. These factors include the following:

• Advanced parental age when child is born
• Low birth weight
• Early birth (prior to 26 weeks of gestation)
• Gender (the rate of autism spectrum disorder among boys is about four times greater than it is among girls)
• Having a parent or sibling who has autism spectrum disorder
• Having certain medical conditions, such as fragile X syndrome or Rett syndrome

Signs and symptoms of autism spectrum disorder

In the most general terms, the signs and symptoms of autism spectrum disorder involve behaviors, social interactions, communication, and thought processes. However, the specific signs and symptoms of autism spectrum disorder that a child will exhibit can vary widely from individual to individual.

The following are examples of the many possible signs and symptoms of autism spectrum disorder:

Behavioral symptoms:

• Not making eye contact
• Flat or monotone speech patterns
• Diminished capacity for speech or poor verbal language skills
• Repetitive body movements (such as rocking back and forth, spinning, or flapping arms)
• Ritualistic behaviors (such as always touching certain objects in a specific order)
• Strict adherence to certain behavior patterns (such as eating the same meals every day)
• Echolalia (verbatim repetition of another person’s words)
• Difficulties with various forms of social interaction, including participating in conversations, maintaining appropriate personal space, and forming friendships
• Failing to respond to one’s name, or otherwise appearing to not hear or acknowledge others
• Apparent lack of interest in others

Physical symptoms:

• Extreme adverse responses to sounds or textures
• Impaired motor skills or coordination
• Disturbed sleep patterns
• Diminished facial expressiveness
• Using gestures inappropriately or not at all

Mental symptoms:

• Inability to recognize and interpret social cues
• Anxiety
• Depression
• Rigid thought patterns
• Experiencing extreme distress due to relatively minor changes
• Fascination with, or fixation on, lights or movement
• Emotional detachment
• Sensation of being overwhelmed in social situations
• Having a narrow range of extremely focused interests

Effects of autism spectrum disorder

As with the signs and symptoms listed in the previous section, the effects of autism spectrum disorder can vary considerably depending upon a variety of individual factors. In general, the following are among the many potential effects of autism spectrum disorder:

• Social withdrawal or isolation
• Difficulty or inability to form and maintain healthy and productive interpersonal relationships
• Difficulty expressing thoughts or engaging in conversation with others
• Diminished capacity for self-care
• Academic setbacks
• Failure to make appropriate developmental progress
• Loss of language, motor, or social skills
• Decreased self-esteem and poor self-confidence

It is important to understand that each child who has autism spectrum disorder will have a unique experience. None of the effects of autism spectrum disorder listed above will definitely apply to all who are diagnosed with this disorder. Also, when a child receives appropriate professional care for autism spectrum disorder, they can avoid certain effects and begin to heal from others.

Autism spectrum disorder and common co-occurring disorders

Children who develop autism may also have an elevated risk for various co-occurring mental health disorders, including the following:

• Attention-deficit/hyperactivity disorder (ADHD)
• Anxiety
• Depression
• Avoidant-restrictive food intake disorder (ARFID)