16 February 2022

Know the signs of Autism — One of the Fastest Growing Developmental Disorders

Written by Dawn Teh

Despite increased public education about Autism (officially called Autism Spectrum Disorder (ASD)), many misconceptions about the condition still exist. This includes myths like "people with autism aren't interested in relationships".¹

In this article, you'll learn about what ASD is, its related risk factors, and more — so you can have a better understanding of the disorder. 

What is ASD and how common is it?

ASD is a developmental disorder where individuals experience difficulties in 2 broad areas of functioning — social interaction and communication, along with flexible behaviour.

It arises in early childhood and is labelled a "spectrum" disorder because there can be great variability in how symptoms present themselves for different individuals.² ³

ASD: A disorder with many names

Over the years, you might have come across various names that all refer to the pattern of social and behavioural issues that characterize ASD.

Asperger's syndrome, high-functioning autism, and pervasive developmental disorder are just some of the other terms that have been used.

You might be wondering if they're still applicable these days. And while some people might mention it in casual conversation, it's not technically recognized anymore.

The existence of these different terms actually created a lot of inconsistencies between how different physicians diagnosed their patients in the past. And experts also wondered whether the fundamental symptoms of all these different diagnoses were actually referring to the same thing.

To clear up the confusion, the American Psychiatric Association removed all these other terms from the Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) in 2013. And instead, they were replaced with a single umbrella diagnosis — ASD, which ranges from mild to severe.⁴ ² ⁵

How prevalent is Autism?

If you're seeing more people in your community being diagnosed with Autism, you might wonder whether its prevalence is increasing. And according to the Centers for Disease Control and Prevention (CDC) in the US, it is.

In their most recent 2018 study, they found that 1 in 44 children across 11 states (aged 8 years) was diagnosed with ASD.

This is up from 1 in 54 children in 2016. And between 2000 to 2016, there was a 178% increase in the prevalence rate.⁶ ⁷ ⁸

Worryingly, ASD is one of the fastest-growing developmental disorders in the US — it's even more common than childhood cancer and diabetes.⁹ ¹⁰ ¹¹

Globally, the average is significantly less at 1 in 160 children.

But the World Health Organization (WHO) states that this is most likely due to under-diagnosis especially in low- to middle-income nations.¹² So the true figure could be higher.

The 2018 CDC report also indicated that boys were 4.2 times more likely than girls to be identified with ASD.

And this figure is similar to worldwide studies. Some experts suggest that this could be because autism symptoms are often overlooked in girls (as it's mostly thought of as a disorder that affects males). However, even if diagnostic biases are accounted for, boys would still be about 3 times more likely than girls to have ASD.¹³

In terms of race, ethnic minorities have had a long-standing history of being disadvantaged when it comes to diagnosing ASD.

This is due to multiple barriers such as cultural stigma or limited access to healthcare.

However, the latest 2018 CDC report has shown some promise as the gap between different races seems to be closing. For example, white children were 1.2 times more likely than black children to be diagnosed with ASD in 2012. But this has dropped to 1.1. times in 2014.¹⁴

Why is ASD on the rise?

The main reason why we're seeing a rise in ASD rates is that it's being identified more effectively. This is a result of streamlining ASD to a single diagnosis, increased public awareness, and community-wide screening of children.

For example, the American Academy of Pediatrics began recommending paediatricians to screen children between 18-24 months for autism during visits since 2016. This could have helped to identify cases that would have normally slipped through the system — like those from minority races.¹¹

Apart from this, some studies suggest that there are other factors that may contribute to the rise in ASD numbers. For example, men who are older (especially after 50 years of age) are more likely to have children with ASD. And increased survival rates of premature babies (who are more likely to develop ASD) may also be another contributing factor.¹⁵ ¹¹

What are the signs of ASD?

The symptoms of ASD fall under 2 broad categories:¹⁶ ³ ²

Difficulties with communicating and interacting socially.

Here's what it might look like in younger children:

  • Not responding to his or her name by 9 months of age. 

  • Does not make or maintain eye contact.

  • Does not show different facial expressions (like happy, sad, or angry) by 9 months of age.

  • Does not show interest in interactive games like peek-a-boo by 12 months.

  • Lack of gesturing like waving goodbye. 

  • Does not approach others to share interests by 15 months — like showing a toy to their caregiver. 

  • Does not point or look at an object you pointed to by 18 months.

  • Does not engage in pretend play by 30 months.

  • Delayed speech development.

Here's what this might look like in an older child:

  • Trouble maintaining a back-and-forth conversation. 

  • Does not initiate or respond to social interactions. Or has unusual ways of engaging in interactions. 

  • Hardly tries to share interests with another person. (e.g. showing loved ones a toy or drawing).

  • Inappropriate or no use of non-verbal communication (e.g. Lack of facial expression or eye contact). 

  • Trouble understanding non-verbal cues.  

  • Troubles establishing or maintaining relationships. 

  • Problems adjusting behaviour to suit various social contexts.

Restricted and/or repetitive patterns of behaviour.

Here's what it might look like in a younger child: 

  • Frequently lines up toys and gets agitated when they are moved out of order. 

  • Always plays the same way and/or with the same toys. 

  • Repeats words or phrases that they hear. 

  • Plays with parts of a toy (e.g. spinning wheels) rather than playing with it as a whole. 

  • Gets very upset with changes to routines. (e.g. taking a different route home or eating new foods). 

  • Repetitive bodily movements (e.g. hand flapping or spinning).

  • Obsessive interests in certain toys. 

  • Unusual reactions to certain sensory aspects of the environment.

Here's what this might look like in an older child:

  • Repetitive or ritualistic movements may still persist. 

  • Insists on objects or schedules being in the same order (e.g. morning routine always has to be the same, utensils need to be placed in the same spot). 

  • Stereotyped use of speech (e.g. repeating phrases from a show in an inappropriate context). 

  • Having very specific topical interests that are sometimes unusual (e.g. astronomy or trains).

  • Unusual sensory interests or aversions may still exist.

Do note that because ASD is a spectrum, symptoms can vary greatly in terms of severity and type. For example, a completely non-verbal child and one that started imitating words at 1 year old can have the same ASD diagnosis.

This is why looking at someone else diagnosed with ASD may not be the best yardstick for determining if another person has the condition.

It's best to get to know each individual's unique issues relating to the disorder.   

Other medical and developmental concerns associated with ASD

ASD is often associated with other medical and developmental issues.

And this can cause confusion in terms of treatment. For example, some may assume these other symptoms are part of ASD and can be left unaddressed.

Understanding how these other problems co-occur with ASD can help you have a better idea of the person as a whole.

Here are some of the most common ones they may face:

1. Attention Deficit Hyperactivity Disorder (ADHD)

ADHD is one of the most common neurodevelopmental co-morbidities that's characterized by inattentiveness, hyperactivity, and impulsivity. It affects an estimated 30-61% of children with autism.¹⁷

2. Sensory Processing Disorder (SPD)

Sensory issues such as overactivity or under-reactivity to stimuli in the environment can form a big part of autism symptoms. And some experts even classify this as a disorder on its own known as Sensory Processing Disorder (SPD). It's not an official diagnosis recognised in the DSM-5. However, there are specific treatments (like sensory integration therapy) that specifically target this issue.¹⁸ ¹⁹

3. Chronic sleep problems

Experts estimate that between 40-80% of children with ASD have sleep issues. And this can include trouble falling asleep, waking frequently at night, or inconsistent sleep patterns. It's also twice as common in autistic children compared to those with other developmental disorders or who are neurotypical.²⁰

4. Anxiety and depression disorders

It's estimated that 11-40% of children and teens with ASD also have anxiety. While depression affects about 7% of children and 26% of adults.¹⁷

5. Gastrointestinal disorders and obesity

A 2014 study found that children with autism are about 4 times more likely to experience diarrhoea, abdominal discomfort, and constipation compared to other kids. Part of the reason for this is that children with ASD are more likely to be picky eaters. But others suggest that there could be some underlying susceptibility to gastrointestinal issues that need to be further investigated.²¹

Related to this is the rising obesity problem in children with ASD. In 2017, the CDC reported that almost a third of children with ASD are considered severely overweight. This is compared to 13% in neurotypical children.²²

6. Seizure disorder

Seizures occur in about 1-2% of children in the general population, but affects 5-38% of children with Autism. Studies have shown overlapping neurobiology and genetics linking the symptoms of both conditions.

However, it's still not clear whether seizures play a contributory role in the development of ASD, or if it works the other way round.²³ ²⁴

7. Schizophrenia

It's estimated that schizophrenia is about 3 times more common in people with ASD compared to the rest of the population. Preliminary studies show that there the 2 conditions may share similar genetic profiles and environmental risk factors.²⁵

How early can ASD be detected?

ASD can be diagnosed as early as 2 years old

Experts diagnose ASD through a rigorous process of screening and in-depth evaluations by multiple professionals (including paediatricians, psychologists, and sometimes speech pathologists).

In many cases, doctors can actually diagnose children by the age of two — and sometimes even earlier at 18 months.

However, the current average age of ASD diagnosis is 4 years old in the US. This 2-year wait between possible and actual diagnosis means that the child loses out on valuable intervention time.

One study found that when children are diagnosed before the age of 4, they're more likely to receive evidence-based treatment like behavioural therapy. While those diagnosed past this threshold are more likely to be treated with medication.

Therefore, many experts stress that increasing public awareness about ASD is essential so that parents can know the signs early and seek help as soon as possible.²⁶ ²⁷ ²⁸

What are the risk factors for ASD?

The exact causes of ASD are complex and continue to perplex researchers to this day. But experts suggest that there are strong genetic factors at play. In fact, it's estimated that ASD is 40-80% heritable. Supporting this is also the fact that having one child with ASD increases the likelihood of their sibling having ASD as well.

However, the mechanisms through which ASD is passed on from generation to generation isn't as straightforward. Unlike certain physical traits which can be controlled by a single gene, ASD has been associated with hundreds of genes. And to complicate matters, it's likely that certain environmental factors need to interact with this genetic predisposition for it to be expressed as ASD.

Some other identified risk factors include mothers taking certain medications (such as valproic acid and thalidomide) during pregnancy. And older fathers (over 50 years old) are also at an increased risk of having children with ASD.²⁹ ³⁰ ³¹

Do vaccines cause ASD?

Many studies have reliably demonstrated that there is no link between vaccines and the development of ASD.

But why are so many people still so convinced that it's the cause? It all started with a study published in 1998 suggesting that there was a link between ASD and the MMR (measles, mumps, and rubella) vaccine — which is usually part of national immunisation programs around the world.

Even though the article was eventually retracted with the author also losing his medical licence, it had done its damage and the effects are still seen today.³²

A recent study in 2017 found that 49% of participants from the US either responded with a "true" or "unsure" to the statement “some vaccines cause autism in healthy children”. Similar results were found from countries like the UK, France, and Italy as well.³³

This is despite the fact that rigorous studies (some even involving a sample size of over 1 million children) have established that no link was found between vaccines and ASD.³⁴

Can ASD be treated?

There is currently no cure for ASD. But there are many treatments that address its symptoms so that the individual can live as full a life as possible.

Depending on the individual's specific symptoms, there will most likely be a mixture of behavioural, speech and communication, and family therapies. These help the individual to manage repetitive behaviours, learn social skills, and improve speech.

As with the diagnostic phase, a multi-disciplinary approach is usually best for treating someone with ASD. For example, psychologists and speech pathologists might focus on modifying behaviours and language development. But may also work with teachers to adjust the school environment to better support the child. This can also be coupled with psychiatrists administering medication to manage specific issues like hyperactivity or agitation.³⁵

Experts also stress that ASD treatment is most effective when addressed early. But unfortunately, the current average age of diagnosis is 4 years old (when it can potentially be picked up at 2 years). Furthermore, a 2016 study found that 30% of children in the US with ASD don't even receive any behavioural or medical treatment at all.³⁶

This is why experts are calling for more parents to seek help early if they suspect that their child is exhibiting ASD symptoms. The earlier that diagnosis and treatment are received, the better the long-term outcome for the individual.

Sources:
  1. Common misconceptions | Autism Association of Western Australia

  2. Autism spectrum disorders | HelpGuide

  3. Autism spectrum disorder (ASD): Diagnostic criteria | Centers for Disease Control and Prevention

  4. The evolution of ‘autism’ as a diagnosis, explained | Spectrum

  5. What happened to Asperger’s syndrome? | The Conversation

  6. One in 44 U.S. children diagnosed with autism, new data suggests | NBC News

  7. Prevalence and characteristics of autism spectrum disorder among children aged 8 years — autism and developmental disabilities monitoring network, 11 Sites, United States, 2018 | Centers for Disease Control and Prevention

  8. Autism statistics & cost | The Autism Community in Action

  9. 30 Facts to know about autism spectrum disorder | Massachusetts General Hospital

  10. Autism spectrum disorders (2015)

  11. New spike in autism numbers may reflect rise in awareness | Spectrum

  12. Autism spectrum disorders | World Health Organization

  13. Autism’s sex ratio, explained | Spectrum

  14. Spotlight on: Racial and ethnic differences in children identified with autism spectrum disorder (ASD) | Centers for Disease Control and Prevention

  15. The real reasons autism rates are up in the U.S. | Scientific American

  16. Signs and symptoms of autism spectrum disorders | Centers for Disease Control and Prevention

  17. Autism statistics and facts | Autism Speaks

  18. Sensory processing disorder (SPD) | Familydoctor.org

  19. Sensory differences | Autism Tasmania

  20. Helping your child with autism get a good night's sleep | WebMD

  21. Large study ties gut issues in autism to inflammation | Spectrum

  22. Autism and obesity: When exercise and healthy diet aren’t enough | Autism Speaks

  23. Seizures in autism | The Autism Community in Action

  24. The link between epilepsy and autism, explained | Spectrum

  25. Schizophrenia prevalence may be threefold higher in people with autism | Spectrum

  26. Autism spectrum disorder | NIH: National Institute of Health

  27. Why autism diagnoses are often delayed | Child Mind Institute

  28. Children diagnosed with autism at earlier age more likely to receive evidence-based treatments | American Psychiatric Association

  29. Genetic causes and modifiers of autism spectrum disorder (2019)

  30. What is autism spectrum disorder? | American Psychiatric Association

  31. What causes autism? What we know, don’t know and suspect | The Conversation

  32. Where did the myth about vaccines and autism come from? | Everyday Health

  33. Autism and vaccines: more than half of people in Britain, France, Italy still think there may be a link | The Conversation

  34. Study of over 1 million children finds no link between MMR vaccine and autism | Oxford Vaccine Group

  35. Autism | Health Direct

  36. Prevalence and treatment patterns of autism spectrum disorder in the United States, 2016 (2019)

The author, Dawn Teh, is a health writer and former psychologist who enjoys exploring topics about the mind, body, and what helps humans thrive.

Find Clinical Trials Today

Join our email list

Want all the latest clinical trial and HealthMatch news in your inbox? We thought you might! Sign up below.

Join our email list

Want all the latest clinical trial and HealthMatch news in your inbox? We thought you might! Sign up below.