Autism Spectrum Disorders

There are five disorders identified that fall within the autism spectrum disorder category. These various types differentiate between the skills, symptoms and levels of ability that fall within the spectrum of behaviors identified as autism. In 2013, the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) modified the definition to remove the specific diagnosis types, and instead categorize them under the inclusive umbrella of “spectrum.”

However, these subcategories are still used widely, and may help with understanding the various symptoms:

• Asperger’s Syndrome: A mild form of autism in which the individual is hyper-focused on specific topics. An Asperger’s diagnosis often describes someone who is highly intelligent, but who may struggle socially.
• Pervasive Developmental Disorder–Not Otherwise Specified (PDD-NOS): This diagnosis is more severe than Asperger’s, but with similar symptoms. 
• Childhood disintegrative disorde: A rare and severe disorder that describes children who begin developing at a normal rate, hitting age and stage milestones for social, language and mental skills until between ages two and four, then begin to lose those skills. 
• Rett Syndrome: This syndrome is typically noticed in infancy, and more common in girls. In recent years it has been reclassified as a genetic mutation, but has symptoms including loss of movement and coordination, speech and communication challenges, and sometimes breathing difficulties.
• Kanner’s Syndrome: Also known as classic autistic disorder, symptoms include avoidance of eye contact, hypersensitivity to sensory stimulation, communication challenges and finding it difficult to understand others. 

Scientists believe that both genetics and environment likely play a role in ASD. ASD occurs in every racial and ethnic group, and across all socioeconomic levels. Males are significantly more likely to develop ASD than females.  

Studies suggest that a person’s genes can act together with aspects of their environment to affect development in ways that lead to ASD. Some factors that are associated with an increased likelihood of developing ASD include:

• Having a sibling with ASD
• Having older parents
• Having certain genetic conditions (such as Down syndrome or Fragile X syndrome)
• Having a very low birth weight

People with ASD also have an increased risk of having epilepsy. Children whose language skills regress early in life—before age three—appear to have a risk of developing epilepsy or seizure-like brain activity. About 20 to 30 percent of children with ASD develop epilepsy by the time they reach adulthood.  

Some factors that are associated with an increased likelihood of developing ASD include:

• Having a sibling with ASD
• Having older parents
• Having certain genetic conditions (such as Down syndrome or Fragile X syndrome)
• Having a very low birth weight

Developmental screening takes a closer look at how your child is developing and is more formal than developmental monitoring. It is a regular part of some well-child visits even if there is not a known concern.

The American Academy of Pediatrics (AAP) recommends developmental and behavioral screening for all children during regular well-child visits at 9, 18, 24 and 30 months, with specific autism screenings at their 18- and 24-month well-child visits. A child may receive additional screening if they have a higher likelihood of ASD or developmental problems. Children with a higher likelihood of ASD include those who have a family member with ASD, show some behaviors that are typical of ASD, have older parents, have certain genetic conditions or had a very low birth weight.

• Identifying children in need of early intervention or special education services
• Sharing relevant information with early intervention or school personnel
• Meeting with early intervention or school personnel and parents or guardians
• Using early intervention or school information in medical diagnostic or treatment plans
• Working within an early intervention, school or school-based health clinic
• Working at an administrative level to improve school functioning around children with special needs

Considering caregivers’ experiences and concerns is an important part of the screening process for young children. The health care provider may ask questions about the child’s behaviors and evaluate those answers in combination with information from ASD screening tools and clinical observations of the child. 

Screening questionnaires and checklists are based on research that compares your child to other children of the same age. Questions may ask about language, movement and thinking skills, as well as behaviors and emotions. Developmental screening can be done by a doctor or nurse, or other professionals in healthcare, community or school settings. Your doctor may ask you to complete a questionnaire as part of the screening process. Screening at times other than the recommended ages should be done if you or your doctor have a concern. Additional screening should also be done if a child is at high risk for disorders (a sibling or other family member has a diagnosis) or if behaviors sometimes associated with disorders are present. If your child’s healthcare provider does not periodically check your child with a developmental screening test, you can ask that it be done.

Symptoms that present in children with ASD vary widely. Some children do not speak at all, while others speak in limited phrases or conversations, and some have relatively average language development. Repetitive play skills and limited social skills are generally evident. Extreme responses to sensory information, such as loud noises and lights, are also common. According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5)—a guide created by the American Psychiatric Association used to diagnose health conditions involving changes in emotion, thinking or behavior (or a combination of these)—symptoms may include:

Social communication and interaction behaviors:

• Making little or inconsistent eye contact
• Appearing not to look at or listen to people who are talking
• Infrequently sharing interest, emotion or enjoyment of objects or activities (including infrequent pointing at or showing things to others)
• Not responding or being slow to respond to one’s name or to other verbal bids for attention
• Having difficulties with the back and forth of conversation
• Often talking at length about a favorite subject without noticing that others are not interested or without giving others a chance to respond
• Displaying facial expressions, movements and gestures that do not match what is being said
• Having an unusual tone of voice that may sound sing-song or flat and robot-like
• Having trouble understanding another person’s point of view or being unable to predict or understand other people’s actions
• Difficulties adjusting behaviors to social situations
• Difficulties sharing in imaginative play or in making friends

Restrictive and repetitive behaviors:

• Repeating certain behaviors or having unusual behaviors, such as repeating words or phrases (a behavior called echolalia)
• Having a lasting intense interest in specific topics, such as numbers, details or facts
• Showing overly focused interests, such as with moving objects or parts of objects
• Becoming upset by slight changes in a routine and having difficulty with transitions
• Being more sensitive or less sensitive than other people to sensory input, such as light, sound, clothing or temperature

People on the autism spectrum also may have many strengths, including:

• Being able to learn things in detail and remember information for long periods of time
• Being strong visual and auditory learners
• Excelling in math, science, music or art

People with ASD may also experience sleep problems and irritability. Symptoms of ASD can last through a person’s lifetime, and some may improve with age, treatment and services. 

Developmental monitoring is an active, ongoing process of watching a child grow and encouraging conversations between parents and providers about a child’s skills and abilities. Developmental monitoring involves observing how your child grows and whether your child meets the typical developmental milestones, or skills that most children reach by a certain age, in playing, learning, speaking, behaving and moving.

Parents, grandparents, early childhood education providers and other caregivers can participate in developmental monitoring. Practitioners may use a brief checklist of milestones depending on age and stage of development (this may include skills like taking a first step, smiling for the first time and waving hello/goodbye) to see how your child is progressing. If you notice that your child is not meeting milestones, talk with your doctor or nurse about your concerns and ask about developmental screening. 

When you take your child to a well visit, your doctor or nurse will also do developmental monitoring. The doctor or nurse might ask you questions about your child’s development or will talk and play with your child to see if they are developing and meeting milestones.

Your doctor or nurse may also ask about your child’s family history. Be sure to let your doctor or nurse know about any conditions that your child’s family members have, including autism spectrum disorder (ASD), learning disorders, intellectual disability or attention-deficit/hyperactivity disorder (ADHD).

ASD can be diagnosed at any age, but symptoms generally appear in early childhood (often within the first two years of life). Doctors diagnose ASD by looking at a person’s behavior and development. The American Academy of Pediatrics recommends that all children get screened for developmental delays and behaviors often associated with ASD at their 18- and 24-month exams.  

The term spectrum refers to the wide range of symptoms, skills and levels of ability in functioning that can occur in people with ASD. ASD affects every person differently; some may have only a few symptoms and signs, while others have many. Some children and adults with ASD are fully able to perform all activities of daily living and may have gifted learning and cognitive abilities, while others require substantial support to perform basic activities. A diagnosis of ASD includes the following disorders that were once diagnosed as separate disorders: Asperger syndrome, autistic disorder, childhood disintegrative disorder and pervasive developmental disorder not otherwise specified.  

In addition to differences or challenges with behavior and difficulty communicating and interacting with others, early signs of ASD may include, but are not limited to:

• Avoiding direct eye contact
• Delayed speech and language skills
• Challenges with nonverbal cues such as gestures or body language
• Showing limited interest in other children or caretakers
• Experiencing stress when routines change 

There is no known cure for ASD. Medications may be used to address specific behavioral problems, and therapy should be specialized according to the needs of each child. Some children with ASD benefit from specialized classrooms, and others function well in standard special education classes or regular classes with additional support.

Therapies and educational/behavioral interventions are designed to remedy specific symptoms and can substantially improve those symptoms. While currently approved medications cannot cure ASD or even treat its main symptoms, there are some that can help with related symptoms such as anxiety, depression and obsessive-compulsive disorder. Medications are available to treat seizures, severe behavioral problems, and impulsivity and hyperactivity. Early intervention plays a critical role in improving the outcome of individuals with ASD.

Treatment for ASD should begin as soon as possible after diagnosis. Early treatment for ASD is important as proper care and services can reduce individuals’ difficulties while helping them build on their strengths and learn new skills.

People with ASD may face a wide range of issues, which means that there is no single best treatment for ASD. Working closely with a healthcare provider is an important part of finding the right combination of treatment and services.

A healthcare provider may prescribe medication to treat specific symptoms. With medication, a person with ASD may have fewer problems with:

• Irritability
• Aggression
• Repetitive behavior
• Hyperactivity
• Attention problems
• Anxiety and depression

People with ASD may be referred to a healthcare provider who specializes in providing behavioral, psychological, educational or skill-building interventions. These programs are often highly structured and intensive, and they may involve caregivers, siblings and other family members. These programs may help people with ASD:

• Learn social, communication and language skills
• Reduce behaviors that interfere with daily functioning
• Increase or build upon strengths
• Learn life skills for living independently

Many services, programs and other resources are available to help people with ASD. Here are some tips for finding these additional services:

• Contact your healthcare provider, local health department, school, or autism advocacy group to learn about special programs or local resources.
• Find an autism support group. Sharing information and experiences can help people with ASD and their caregivers learn about treatment options and ASD-related programs.
• Record conversations and meetings with healthcare providers and teachers. This information may help when it’s time to decide which programs and services are appropriate.
• Keep copies of health care reports and evaluations. This information may help people with ASD qualify for special programs.

Once an evaluation is completed, the basic approach to caring for individuals with ASD is to teach learning skills by building on the child’s abilities and strengths while correcting disabilities and weaknesses. Other professionals such as speech and language therapists also may help. Some medications may help the child learn by enhancing attention and concentration. Psychological therapies may also be used.

Many services, programs, and other resources are available to help people with ASD. Here are some tips for finding these additional services:

• Contact your healthcare provider, local health department, school or autism advocacy group to learn about special programs or local resources.
• Find an autism support group. Sharing information and experiences can help people with ASD and their caregivers learn about treatment options and ASD-related programs.
• Record conversations and meetings with health care providers and teachers. This information may help when it’s time to decide which programs and services are appropriate.
• Keep copies of healthcare reports and evaluations. This information may help people with ASD qualify for special programs.

To learn more about your diagnosis, consider participating in a clinical trial so clinicians and scientists can learn more about ASD and related disorders. Clinical studies use human volunteers to help researchers learn more about a disorder and perhaps find better ways to safely detect, treat or prevent disease.

All types of volunteers are needed—those who are healthy or may have an illness or disease—of all different ages, sexes, races and ethnicities to ensure that study results apply to as many people as possible, and that treatments will be safe and effective for everyone who will use them.

For information about participating in clinical research, visit NIH Clinical Research Trials and You. Learn about clinical trials currently looking for people with PDD at Clinicaltrials.gov.