Autism Spectrum Disorder

Ethan Cullen
Author: Ethan Cullen Medical Reviewer: Dr. Brittany Ferri, PhD Last updated:

Autism Spectrum Disorder is a developmental disability [1] that causes differences in the way the brain works. Individuals with autism may have difficulty with socialization, understanding emotions, and processing sensory information, such as loud noises and bright lights. ASD is not a disease or illness, people who have it will have it for their whole life. ASD is not something that can be ‘cured’, but people with autism often need help with some things that others may find easier [2].

What is autism spectrum disorder?

Autism Spectrum Disorder is a relatively new term that covers a range of disabilities that were once treated as separate things, including Autism and Asperger’s Syndrome. Individuals with autism can show difficulty: [2]

  • Socializing and making new friends
  • Understanding other people’s emotions
  • Adjusting to new and unfamiliar situations
  • Dealing with certain types of sensory input they find overwhelming

Autism is not linked with a single cause. You cannot give your child ASD through bad parenting or vaccination [2], but it is thought to be something that can be inherited or come from environmental factors. The CDC estimates that 2.3% of 8-year-old children in the United States have ASD as of 2018 [4].

Individuals with autism live full lives, it just means that they might need help with some symptoms that they find particularly challenging. ASD is not something that you can ‘cure’ – an autism diagnosis is for life and people will require different amounts of support.

Types of ASD

Before autism spectrum disorder was given as a formal diagnosis for all individuals with autism, there were other terms used to diagnose people. Some of these may still be helpful and used today, however you should always check how people want to refer to their disability. [3]

  • Asperger’s syndrome was used to describe people with autism who may not have some of the physical disabilities associated with autism. They may  struggle to understand social cues and feel anxious or overwhelmed by some social situations.
  • Autistic disorder
  • Pervasive developmental disorder

Symptoms of autism spectrum disorder

The signs and symptoms of ASD can vary massively depending on the person. There are early signs of autism that you may be able to notice in your child, along with other symptoms that affect adults and adolescents.

Early signs of ASD [1]

  • Using few gestures to show emotion or interact with others, like not waving goodbye
  • Doesn’t show obvious facial expressions like happy or sad by 9 months of age, which is the expectation for this behavior as per the CDC’s developmental milestones
  • Does not notice when other children are hurt or upset by 24 months as expected
  • Does not like to ‘play pretend’ like dressing up as a nurse or superhero by 4 years old as suggested by the CDC
  • Does not share interests with you like showing you a favourite toy by 18 months, as is expected at this age per the CDC
  • Does not like toys to be put out of place and will reorganise their toys if they are cleaned up
  • Unusual reactions to different senses and particular noises
  • Delayed language skills

Social communication and interaction [3]

  • Individuals with autism spectrum disorder generally struggle to understand verbal and non-verbal communication; however this can vary. Some people with ASD are unable to speak or have limited speech, whilst others may be able to speak perfectly fine. Some might resort to autism scripting, where an individual uses pre-prepared scripts for various situations.
  • They may take things literally and struggle to understand abstract concepts or sarcastic tones
  • They may need time alone when they feel overwhelmed by social interaction
  • Difficultly reading other people’s emotions which can lead to difficulties making or keeping friends

Restricted or repetitive behaviors and interest [3]

  • Individuals with autism may like to form routines with things like the route to school or work, and can become overwhelmed or upset if these routines are disrupted
  • Repetitive movements like hand flapping, rocking, or use of a fidget toy can help to calm themselves in stressful situations
  • Many people with autism find interests that they will focus a lot of their time on. These interests can become fundamental to their happiness, however on occasion they can begin to neglect some other things like subjects they do not enjoy in school.

Long-term complications

If the right support isn’t given to  individuals with autism, then some more severe complications can begin to develop [1]

  • Epilepsy or seizure disorders
  • Unusual or unhealthy eating habits
  • Gastrointestinal issues such as constipation
  • Other mental disorders such as anxiety and depression

Diagnosing autism spectrum disorder

Diagnosing ASD is not as simple as a blood test. A screening by a health care professional needs to happen for diagnosis of autism spectrum disorder, and this can happen reliably from around 2 years of age [1]. An autism assessment can be carried out on a child with the parent present, or you can get an adult diagnosis if you think you may have it.

When going for the assessment, they may ask [2]:

  • Of any symptoms you or a close relative have noticed over time
  • If you or your child has had any trouble socializing or communicating. They may observe the behavior of your child during the assessment

As both child and adult ASD diagnoses rely on testimony from close relatives, it is important to take note of any symptoms you think your child is showing as they develop to help a potential diagnosis.

Developmental screening is more formal than just monitoring. It involves a healthcare professional taking a closer look at how your child is developing. They will usually ask you some questions about the language, movement, behavior, and emotions of your child.

Developmental screenings will usually take place during early childhood before 3 years old, however, they may be more frequent if they are believed to be at higher risk of ASD (for example if a sibling also has it) [1].

Causes of autism spectrum disorder

There is not a single identifiable cause of ASD; it is likely to be a combination of factors. However, there are certain risk factors that have shown a link to ASD:

  • There may be a genetic reason behind the development of autism, however, scientists are unsure if this is due to a specific rare gene or common genes interacting in a rare way [5]
  • Having parents or siblings with ASD may increase your risk of having it. It appears that there is between a 74% and 93% risk that ASD is heritable [6]
  • Complications during the pregnancy, like gestational diabetes, have been shown to increase risk compared to siblings where the mother did not experience the same complications [7]
  • Being born to older parents may also increase the risk of autism

There has been no evidence to suggest that vaccines, or commonly blamed vaccine components like thimerosal and mercury, have any link to the development of ASD in childhood or adolescence [8]

Living with autism spectrum disorder

There is controversy surrounding the way some literature talks about autism. Some organizations suggest that we change our vocabulary to exclude words like ‘treatment’ as that should not be the goal with ASD [3]. It is more fitting to refer to rehabilitative therapies as helping people and their families better manage ASD.

However, there are some medications available to help deal with specific symptoms.

  • Some medication may be prescribed if you or your child are hyperactive, and it disrupts daily activities
  • Antidepressants can be given to counter symptoms like anxiety or depression.

The goal is not to ‘cure’ autism, rather it is to help individuals with autism deal with the challenges they face in day-to-day life and improve their quality of life and independence. There are extensive support measures that people with autism can use, and many will be able to care for themselves with only some minor adjustments to their life.


Educational support ensures that children with autism spectrum disorder do not fall behind and can still complete work like their peers. This can include things like structuring the day differently for the child to fit their needs and offering a 1-to-1 specialist teacher for familiarity. Specialist schools may be able to provide better support to those that need it [2]

High schools and universities can also offer tailored support to accommodate for certain needs, like allowing for extra time in exams.

Developmental Approaches

These focus on developing skills that autistic people may struggle with, such as language skills or physical skills.

  • Speech and language therapy [1] can help with lots of different forms of communication. Individuals with autism can be what is called ‘non-verbal’. In these therapy sessions, they can use pictures or a tablet device to help communicate. These therapy sessions can also help to understand social cues that they may struggle to pick up
  • Occupational therapy involves developing the skills needed to live and work independently like dressing, bathing, and eating by themselves.
  • Physical therapy focuses on improving both small and large movement skills.

Helping people with autism

There are some ways that you can help as a parent of a child with autism: [2]

  • Frequently use your child’s name so they know you are talking to them
  • Keep language simple and speak slowly
  • Be patient with your child and realize they may need more time to understand than other children
  • Try not to have a conversation where it is noisy
  • Don’t use lots of idioms that have non-literal meanings (e.g. ‘break a leg’)

It may help to speak to local healthcare professionals or social service agencies when your child is approaching adulthood to know about the changes in support for them. Speaking to potential universities directly when applying can also help them settle into the next stage of their life easier.

  1. National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention (n.d.) Accessed through:
  2. ‘What is Autism?’ NHS UK (7th September 2022) Accessed through:
  3. ‘What is Autism?’ UK National Autistic Society (n.d.) Accessed through:
  4. Autism Spectrum Disorder (ASD). (n.d.). National Institute of Mental Health (NIMH).
  5. Abrahams BS, Geschwind DH (May 2008). “Advances in autism genetics: on the threshold of a new neurobiology”. Nature Reviews. Genetics. 9 (5): 341–355
  6. Lord C, Elsabbagh M, Baird G, Veenstra-Vanderweele J (August 2018). “Autism spectrum disorder”. Lancet. 392 (10146): 508–520
  7. Gardener H, Spiegelman D, Buka SL (August 2011). “Perinatal and neonatal risk factors for autism: a comprehensive meta-analysis”. Pediatrics. 128 (2): 344–55.
  8. Taylor LE, Swerdfeger AL, Eslick GD (June 2014). “Vaccines are not associated with autism: an evidence-based meta-analysis of case-control and cohort studies”. Vaccine. 32 (29): 3623–3629.
Medical Content

Our Medical Affairs Team is a dedicated group of medical professionals with diverse and extensive clinical experience who actively contribute to the development of our content, products, and services. They meticulously evaluate and review all medical content before publication to ensure it is medically accurate and aligned with current discussions and research developments in mental health. For more information, visit our Editorial Policy.

About is a health technology company guiding people towards self-understanding and connection. The platform offers reliable resources, accessible services, and nurturing communities. Its mission involves educating, supporting, and empowering people in their pursuit of well-being.

Ethan Cullen
Author Ethan Cullen Writer

Ethan Cullen is a medical writer with a Bachelor of Arts degree in Philosophy, Politics, and Economics from Oxford University.

Published: Nov 8th 2022, Last edited: Feb 21st 2024

Brittany Ferri
Medical Reviewer Dr. Brittany Ferri, PhD OTR/L

Dr. Brittany Ferri, PhD, is a medical reviewer and subject matter expert in behavioral health, pediatrics, and telehealth.

Content reviewed by a medical professional. Last reviewed: Nov 9th 2022