Prevalence & Diagnosis
Autism spectrum disorder (ASD) is a complex developmental disability, which can significantly affect a person’s behavior and his/her ability to communicate and interact socially with others. Typically, the signs of autism appear during the early childhood years and in most cases, last throughout a person’s life, although interventions and services can improve symptoms over time. ASD occurs in all ethnic, racial, and socioeconomic groups.
About 1 in 54 children has been identified with an autism spectrum disorder (ASD) according to recent estimates from the CDC’s Autism and Developmental Disabilities Monitoring (ADDM) Network. It is 4.3 times as prevalent among boys as among girls.
Autism is known as a “spectrum” disorder because individuals can vary significantly in the type and severity of symptoms they experience. Two individuals with the same diagnosis can act quite different from one another and have varying capabilities, behaviors, and strengths.
In general, ASD refers to a range of conditions typically characterized by some degree of difficulty in the areas of social skills, repetitive behaviors, and speech and communication. Individuals with autism may experience some level of motor skill differences, language and communication challenges, intellectual impairment, executive functioning difficulty, emotional challenges, and sensory sensitivities. Some individuals with ASD may require a great deal of assistance with daily living tasks and others require much less.
The Centers for Disease Control and Prevention (CDC) (2018) provides the following examples of possible signs and symptoms of autism that children or adults with ASD may exhibit:
- May not point at objects to show interest
- May not look at objects when another person points at them
- May have trouble relating to others
- May avoid eye contact
- May have trouble understanding other people’s feelings or talking about their own feelings
- May prefer not to be held or cuddled
- May appear to be unaware when people talk to them, but respond to other sounds
- May be very interested in people, but not know how to talk, play, or relate to them
- May repeat or echo words or phrases said to them
- May have trouble expressing their needs using typical words or motions
- May repeat actions over and over again
- May have trouble adapting when a routine changes
- May have unusual reactions to the way things smell, taste, look, feel, or sound
In addition to these possible characteristics and behaviors, individuals with autism can also present with unique abilities and strengths as well as intense passions and interests. Many people with autism have different ways of learning and engaging with the world, and may need understanding, guidance, and modifications to help them uncover the approach which works best for their unique needs.
Comorbid medical and health issues frequently affecting individuals with autism include seizures, anxiety, depression, gastrointestinal disorders, immune dysfunction, metabolic abnormalities, mitochondrial dysfunction, sleep disturbances, food sensitivities and intolerances, and attention deficit hyperactivity disorder.
Diagnosing autism spectrum disorders can be challenging as there is currently no concrete medical test, to diagnose the disorders. Currently, diagnosis is based on observation of development and behavioral symptoms outlined in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). Because symptoms vary considerably from individual to individual, diagnosis can be quite challenging, and because it is a developmental disability, autism may affect an individual differently at different stages of their lifespan. Full-text of the diagnostic criteria for autism spectrum disorder can be found on the Autism Speaks website.
American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Arlington, VA: American Psychiatric Association, 2013.
Baio J, Wiggins L, Christensen DL, et al. Prevalence of Autism Spectrum Disorder Among Children Aged 8 Years — Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2014. MMWR Surveill Summ 2018;67(No. SS-6):1–23. DOI: http://dx.doi.org/10.15585/mmwr.ss6706a1.
Division of Birth Defects, National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention. (2018, May). Basics About ASD. https://www.cdc.gov/ncbddd/autism/facts.html.
Division of Birth Defects, National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention (2015, February). Autism Spectrum Disorder: Screening and Diagnosis. https://www.cdc.gov/ncbddd/autism/screening.html.
Hyman, S.L. (2013). New DSM-5 includes changes to autism criteria. AAP News, June 2013.
Maenner MJ, Shaw KA, Baio J, et al. Prevalence of Autism Spectrum Disorder Among Children Aged 8 Years — Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2016. MMWR Surveill Summ 2020;69(No. SS-4):1–12. DOI: http://dx.doi.org/10.15585/mmwr.ss6904a1external icon.
McDougle, C.M. (Ed.). (2016). Primer on Autism Spectrum Disorder. New York, NY: Oxford University Press.
Cause, Cure, & Interventions
There is no known single cause of autism spectrum disorder. Although many theories regarding the etiology of autism have been proposed and explored, the cause is not yet clear. This issue is currently the focus of many autism research endeavors. Over the years, it has been suggested that autism may be caused by genetic, immunological, metabolic, and environmental factors. Research investigating the causes of autism has focused on a range of topics including unstable gene clusters, irregular genetic code, viral infections during pregnancy, maternal metabolic imbalances, exposure to chemicals and environmental toxins, and prematurity and complications during delivery.
It is generally accepted that there is not one autism, but instead many different types of autism, caused by a combination of genetic and environmental factors which have resulted in abnormalities in brain structure and function.
There is no known cure for autism, and there are diverse views amongst those in the autism community regarding the possible benefits of a cure.
There are currently no medications which can cure ASD; however, some medications have been explored in treating the associated behavioral symptoms of autism and in helping some people with autism to function more independently on a daily basis. Medications might not affect all autistic individuals in the same way, and in some cases, it is questioned whether the negative side effects of the treatment outweigh benefits.
Research has shown that early diagnosis and early intervention can lead to significantly improved outcomes and can help children with autism learn important skills, including how to talk to and interact with others. Early intervention focuses on helping young children learn basic physical, cognitive, communication, social/emotional, and self-help skills.
Treatments and interventions for autism include Applied Behavior Analysis (ABA), Treatment and Education of Autistic and Related Communication-handicapped Children (TEACCH), Developmental Individual-Difference Relationship-based Model/Floortime, Relationship Development Intervention, auditory training, intensive educational therapy, sensory integration therapy, music therapy, play therapy, augmentative and alternative communication (AAC) strategies, including supported typing and the Picture Exchange Communication System (PECS), pharmacological treatments, and comprehensive treatment programs. Additionally, many individuals benefit from treatment for particular symptoms of autism, such as speech, occupational, and physical therapy.
Autism Across the Lifespan
Contrary to common public misconception, autism is not just a childhood condition. Autism is a developmental disorder which often affects an individual throughout the lifespan; however, only a very small proportion of autism research, education, and service endeavors address issues that affect adults with autism. The majority of public attention and autism research focuses on children with autism, many interventions for autism are appropriate only for children, and most services available are geared primarily towards children.
The reality is that the majority of these children with autism grow up to become adults with autism who are then left with significantly fewer resources and options. Because the necessary supports change considerably as people with autism age, a greater variety of services, supports, and programs geared toward adults are needed to ensure a higher quality of life for people with autism as they age.
As an individual with autism transitions out of high school, there are a number of post-school options that must be considered, such as postsecondary education, vocational training, supported employment, independent living, and community participation. As individuals with autism and their parents or caregivers get older, the issue of long-term life planning becomes more salient. Caregivers must ensure that the needs and desires of their loved one with special needs will be addressed once they are gone. This can be a complex process as the individual and caregiver must make decisions regarding the individual’s medical care, living arrangements, daily activities, community participation, employment, religious involvement, guardianship, and long-term financial planning. As more communication strategies become available, individuals with autism are increasingly able to communicate their own lifespan needs and desires and take a more active role in the decision-making process.
Challenging assumptions about adults with autism might help ensure that appropriate supports are developed for this population. For example, the assumption that autistic people’s unusual behaviors indicate that they do not wish to socialize has had profound effects on the way that they are treated (Jaswal and Akhtar, 2018). Uncovering alternative explanations for these behaviors and challenging the assumption that autistic people are not interested in socializing will foster the development of more appropriate and fulfilling opportunities for these adults.
Addressing the needs of adults with autism as they age has become a priority for the NLM Family Foundation. Aging Well with Autism provides a more detailed discussion of the various topics and challenges families encounter as their loved ones with autism approach this later life stage.
Jaswal, V., & Akhtar, N. (2018). Being vs. Appearing Socially Uninterested: Challenging Assumptions about Social Motivation in Autism. Behavioral and Brain Sciences, 1-84. doi:10.1017/S0140525X18001826