Autism 101

Most-read articles

Illustration of a pregnant woman seated next to a large diagram of the brain featuring chromosomes, bacteria and other microbes.
Spectrum Microphone

The link between maternal infection and autism, explained

Having an infection during pregnancy is tied to a small increase in the chances of having an autistic child, but the connection may not be causal.

By Charles Q. Choi
13 December 2022 | 7 min read
Children scattered around a grid with a beam counting them
Spectrum Microphone

Autism prevalence in the United States, explained

The bulk of the increase in autism prevalence stems from a growing awareness of the condition and changes to the diagnostic criteria.

By Jessica Wright
3 September 2020 | 8 min read
Illustration shows child's head, with an EEG background, and a sleeping figure floating in the clouds above his head.
Spectrum Microphone

Sleep problems in autism, explained

Many people with autism have difficulty falling and staying asleep, but there may be ways to help them.

By Hannah Furfaro
6 February 2020 | 6 min read
Illustration shows a woman whose mouth is covered by a cloud and whos eyes are covered by a cloud.
Spectrum Microphone

Double empathy, explained

The double empathy theory challenges the idea that social difficulties are specific to autism and suggests that problems arise from a mismatch in perspective between autistic and non-autistic people.

By Rachel Zamzow
22 July 2021 | 8 min read

Autism theories and research

Illustration of a strong man holding up a oversized brain
Spectrum Microphone

The extreme male brain, explained

The ‘extreme male brain’ theory suggests that autism is an exaggeration of systematic sex differences in ways of thinking.

By Hannah Furfaro
1 May 2019 | 5 min read
Spectrum Microphone

The female protective effect, explained

One of the leading theories of autism posits that girls and women are biologically protected from the condition.

By Hannah Furfaro
1 May 2019 | 4 min read
Spectrum Microphone

The signaling imbalance theory of autism, explained

The signaling imbalance theory holds that the brains of autistic people are hyper-excitable because of either excess neuronal activity or weak brakes on that activity.

By Sarah DeWeerdt
1 May 2019 | 4 min read
Illustration shows the world is distorted through a point of view pair of glasses
Spectrum Microphone

The predictive coding theory of autism, explained

In autism, a person's brain may not form accurate predictions of imminent experiences, or even if it does, sensory input may override those predictions.

By George Musser
1 May 2019 | 6 min read
overlapping network of connections in the brain
Spectrum Microphone

The connectivity theory of autism, explained

A growing body of evidence suggests that autism involves atypical communication between brain regions, but how and where in the brain this plays out is unclear.

By Rachel Zamzow
1 May 2019 | 4 min read
Illustration of red figures on a big blue brain are serotonin signaling

Serotonin’s link to autism, explained

Serotonin, the brain chemical best known for its link to depression, may also be involved in autism.

By Nicholette Zeliadt
1 May 2019 | 5 min read
many hands reaching for and sharing papers
Spectrum Microphone

Preprints of autism research, explained

Over the past decade, biologists have increasingly been posting their research results on preprint servers, ahead of the results' publication in traditional scientific journals.

By Michael Marshall
11 March 2020 | 7 min read
Illustration shows a woman whose mouth is covered by a cloud and whos eyes are covered by a cloud.
Spectrum Microphone

Double empathy, explained

The double empathy theory challenges the idea that social difficulties are specific to autism and suggests that problems arise from a mismatch in perspective between autistic and non-autistic people.

By Rachel Zamzow
22 July 2021 | 8 min read
A DNA helix showing common and rare variants
Spectrum Microphone

The multiple hits theory of autism, explained

Researchers are studying how a combination of genetic ‘hits’ may contribute to autism’s diversity.

By Jessica Wright
1 May 2019 | 4 min read
Child stands with back to group of large signs offering directions.
Spectrum Microphone

Pathological demand avoidance in autism, explained

Some clinicians say the term describes a subtype of autism, but others dispute its validity and say it is harmful to the autistic community.

By Peter Hess
11 August 2022 | 6 min read
a microscope shines light on a stack of bills

Funding for autism research, explained

Biomedical research costs money. And applying for research funding can be a long and complicated process.

By Giorgia Guglielmi
25 May 2020 | 6 min read

Biological factors

Playful clay chromatin strand is not plugged in, there fore, not turned on
Spectrum Microphone

Autism’s link to chromatin remodeling, explained

Many of the genes strongly linked to autism are involved in the remodeling of chromatin, the complex of DNA and proteins that makes up chromosomes. Scientists are just beginning to understand why.

By Giorgia Guglielmi
6 July 2021 | 6 min read
Illustration of DNA helix highlighting the methylation process.
Spectrum Microphone

DNA methylation in autism, explained

How chemical tags called methyl groups position themselves on genetic sequences may hint at some of the causes of autism.

By Anna Goshua
13 December 2021 | 5 min read
Hands on background of microarray and other genetic information
Spectrum Microphone

Genetic testing for autism, explained

No genetic test can say whether a person has autism, but it may point to a cause for the condition or for any related complications.

By Jessica Wright
10 April 2019 | 5 min read
stork flying with an alarm clock, dice and a crescent moon

The link between parental age and autism, explained

Older men and women are more likely than young ones to have a child with autism, but this connection is not straightforward.

By Sarah DeWeerdt
28 January 2020 | 6 min read
Illustration shows a maze of elements: human brain, medicine, chromosome, factory, clouds and lightning bolts
Spectrum Microphone

Environmental risk for autism, explained

Autism results from an interplay between genetics and the environment, but it has been tough to nail down the environmental factors involved.

By Sarah DeWeerdt
5 November 2018 | 6 min read
Illustration of research mice forming the letter 'X'.
Spectrum Microphone

Fragile X syndrome’s link to autism, explained

Fragile X syndrome is a leading genetic cause of autism. People who have either condition often share certain traits, such as difficulties in social situations.

By Hannah Furfaro
10 October 2018 | 6 min read
linked hands in a pattern intertwined with DNA showing some broken parts, symbolizing mutations

Rett syndrome’s link to autism, explained

Studies of Rett syndrome hint at genes, cells and brain circuits that may be involved in autism — and may pave the way to treatments for both conditions.

By Sarah DeWeerdt
21 October 2019 | 5 min read

The link between antidepressants and autism, explained

Taking antidepressants during pregnancy is unlikely to raise the risk of having a child with autism.

By Jessica Wright
6 September 2018 | 5 min read
Illustration shows heads and brains inside at various sizes.
Spectrum Microphone

Autism’s relationship to head size, explained

Some people with autism have an unusually large head. What causes the enlargement? And does it have any bearing on outcome?

By Michael Marshall
9 April 2020 | 6 min read
DNA helix inside the human body
Spectrum Microphone

Autism genetics, explained

The more scientists dig into DNA, the more intricate its contribution to autism seems to be. Here, we unravel the complex genetics of autism.

By Nicholette Zeliadt
28 May 2021 | 5 min read
Baby in utero surrounded by pills, on bright blue background
Spectrum Microphone

The link between vitamins, supplements and autism, explained

Too little — or too much — of certain substances during pregnancy may increase the odds of having a child with autism. Here we explain what scientists know about these associations.

By Peter Hess
14 April 2021 | 6 min read
four brain areas marked with flags: Cortex, amygdala, hippocampus, cerebellum
Spectrum Microphone

Brain structure changes in autism, explained

Autistic people have distinct patterns of brain development, which sometimes result in differences in brain structure. Here's what we know about those differences.

By Angie Voyles Askham
15 October 2020 | 6 min read

Diagnosis and interventions

Illustration of a form being signed.
Spectrum Microphone

Decisional capacity and informed consent, explained

To include more autistic people in research, here's what scientists need to know about informed consent procedures for study participants who have impaired decision-making capacity.

By Emmet Fraizer
23 January 2023 | 7 min read
Children scattered around a grid with a beam counting them
Spectrum Microphone

Autism prevalence in the United States, explained

The bulk of the increase in autism prevalence stems from a growing awareness of the condition and changes to the diagnostic criteria.

By Jessica Wright
3 September 2020 | 8 min read
People standing with shapes around them

The evolution of ‘autism’ as a diagnosis, explained

From a form of childhood schizophrenia to a spectrum of conditions, the characterization of autism in diagnostic manuals has a complicated history.

By Lina Zeldovich
9 May 2018 | 7 min read
An illustration shows colored blocks with a child's hand and an adult's hand moving them.

Early interventions, explained

The accepted wisdom in autism research holds that early intervention offers the best promise for an autistic child’s well-being. But how effective are these therapies?

By Jen Monnier
4 October 2018 | 7 min read
A drawing shows the word 'autism' formed of loose letters under a magnifying glass.
Spectrum Microphone

Autism diagnosis, explained

New and improved autism screens and diagnostic tools promise to streamline the long path to an autism diagnosis.

By Hannah Furfaro
5 November 2018 | 5 min read
Illustration of a neuron on top of a marijuana leaf surrounded by psychadelic colors.
Spectrum Microphone

Cannabis and autism, explained

Autistic people and their families are increasingly experimenting with marijuana to try to ease problems such as insomnia, epilepsy and chronic pain — and traits of autism. But there is little evidence for its safety or effectiveness.

By Peter Hess
7 September 2020 | 8 min read

Living with autism

The illustration shows two plates of food, one full of a variety of foods, and another with a few foods arranged in a particular way.
Spectrum Microphone

Anorexia’s link to autism, explained

People with anorexia are more likely to be autistic than those without the eating disorder, but the interplay between the two conditions is complex.

By Laura Dattaro
7 December 2020 | 7 min read
a green head has a 'top' that is red--and a hand is lifting the top to let steam out.
Spectrum Microphone

Autistic burnout, explained

‘Autistic burnout’ is the intense physical, mental or emotional exhaustion, often accompanied by a loss of skills, that some adults with autism experience.

By Sarah DeWeerdt
30 March 2020 | 4 min read
two layers of hands in motion overlap in red and blue
Spectrum Microphone

Repetitive behaviors and ‘stimming’ in autism, explained

Restricted interests and repetitive behaviors constitute one of two criteria that define autism in the diagnostic manual for psychiatry.

By Sarah DeWeerdt
31 January 2020 | 6 min read
Illustration shows child's head, with an EEG background, and a sleeping figure floating in the clouds above his head.
Spectrum Microphone

Sleep problems in autism, explained

Many people with autism have difficulty falling and staying asleep, but there may be ways to help them.

By Hannah Furfaro
6 February 2020 | 6 min read
silhouette of head with illustrated text
Spectrum Microphone

Social communication in autism, explained

Communication problems have always been considered a core feature of autism. Yet there are substantial and wide-ranging differences in how people with autism communicate.

By Lydia Denworth
19 April 2018 | 5 min read
a human brain model made of springs is shaking on its spring base

The link between epilepsy and autism, explained

Autism and epileptic seizures often go hand in hand. What explains the overlap, and what does it reveal about autism’s origins?

By Jessica Wright
21 October 2019 | 4 min read
Spectrum Microphone

Conditions that accompany autism, explained

More than half of people on the spectrum have four to five other conditions. Which conditions, and how and when they appear, varies from one autistic person to the next.

By Hannah Furfaro
25 July 2018 | 5 min read
Female head shape cut out of pink paper, under magnifying glass. Male head is in blue, opposite the female.

Autism’s sex ratio, explained

More boys than girls have autism; diagnostic biases and genetic factors may explain the skewed sex ratio.

By Nicholette Zeliadt
13 June 2018 | 4 min read
Illustration showing two hands plugging cables into different areas of the brain, eg. prefrontal cortex, motor cortex, etc.
Spectrum Microphone

Motor difficulties in autism, explained

Most people with autism have motor difficulties, ranging from an atypical gait to problems with handwriting, but researchers still have much to learn about their causes and consequences.

By Lauren Schenkman
13 August 2020 | 7 min read
Illustration of hand pressing one orange button on a keyboard with keys of various colors.
Spectrum Microphone

Gender and sexuality in autism, explained

Gender and sexuality appear to be more varied among autistic people than among neurotypical people. What do scientists know about the connection?

By Laura Dattaro
18 September 2020 | 8 min read

Explore more from The Transmitter

Research image of neurons in the fly’s ventral nerve cord.

New connectomes fly beyond the brain

Researchers are mapping the neurons in Drosophila’s ventral nerve cord, where the central nervous system meets the rest of the body.

By Laura Dattaro
26 July 2024 | 7 min read
Illustration of researchers talking to laypeople amidst strands of DNA.

Building an autism research registry: Q&A with Tony Charman

A purpose-built database of participants who have shared genomic and behavioral data could give clinical trials a boost, Charman says.

By Cathleen O’Grady
25 July 2024 | 8 min read

Cerebellar circuit may convert expected pain relief into real thing

The newly identified circuit taps into the brain’s opioid system to provide a top-down form of pain relief.

By Angie Voyles Askham
24 July 2024 | 6 min read