Special Reports Curated collections of articles on special topics in autism.
ILLUSTRATION BY
LAURÈNE BOGLIO

How is autism diagnosed? What explains the rise in autism’s prevalence? How much do genes contribute to the condition? What about the environment?

In this section of Spectrum, dubbed Autism 101, we answer these and other questions about autism. Each article pulls together the latest science to reflect what we know.

Autism 101 is designed to both provide information and highlight knowledge gaps, indicating where data on a subject are absent or contradictory. Like our understanding of autism, this section is evolving, so please check back often.


Featured Articles

A drawing shows the word "autism" formed of loose letters under a magnifying glass.

Autism diagnosis, explained

by  /  5 November 2018

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

DNA inside of human form

Autism genetics, explained

by  /  27 June 2017

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

Illustration shows a maze of elements: human brain, medicine, chromosome, factory, clouds and lightning bolts

Environmental risk for autism, explained

by  /  5 November 2018

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

Conditions that accompany autism, explained

by  /  25 July 2018

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.

Autism rates in the United States explained

by  /  2 March 2017

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

An illustration shows colored blocks with a child's hand and an adult's hand moving them.

Early interventions, explained

by  /  4 October 2018

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?

Illustration of research mice forming the letter "X".

Fragile X syndrome’s link to autism, explained

by  /  10 October 2018

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.

silhouette of head with illustrated text

Social communication in autism, explained

by  /  19 April 2018

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.

The link between antidepressants and autism, explained

by  /  6 September 2018

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

child with someone sleeping in cloud-like brain

Sleep problems in autism, explained

by  /  13 November 2017

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

Female head shape cut out of pink paper, under magnifying glass. Male head is in blue, opposite the female.

Autism’s sex ratio, explained

by  /  13 June 2018

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

stork flying with an alarm clock, dice and a crescent moon

The link between parental age and autism, explained

by  /  29 November 2017

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

People standing with shapes around them

The evolution of ‘autism’ as a diagnosis, explained

by  /  9 May 2018

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

Hands on background of microarray and other genetic information

Genetic testing for autism, explained

by  /  10 April 2019

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.

The signaling imbalance theory of autism, explained

by  /  1 May 2019

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.

A DNA helix showing common and rare variants

The multiple hits theory of autism, explained

by  /  1 May 2019

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

overlapping network of connections in the brain

The connectivity theory of autism, explained

by  /  1 May 2019

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.

The female protective effect, explained

by  /  1 May 2019

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

Illustration of a strong man holding up a oversized brain

The extreme male brain, explained

by  /  1 May 2019

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

Illustration shows the world is distorted through a point of view pair of glasses

The predictive coding theory of autism, explained

by  /  1 May 2019

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.

Illustration of red figures on a big blue brain are serotonin signaling

Serotonin’s link to autism, explained

by  /  1 May 2019

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