The psychiatrists who literally write the book on the definitions of mental illness have announced their plan to group all autism spectrum disorders, including Asperger syndrome, under a single category.

A new report adds to the wave of research on autism risk that’s shifting the focus from older fathers to older mothers.

Here’s a remarkable statistic you may not have heard: white children are two to three times more likely to be diagnosed with autism than are their Hispanic peers.

An early intervention method called the Early Start Denver Model can help children with autism improve their language and behavioral skills, and raise their intelligence quotients, according to a study published in Pediatrics.

Deletions or duplications of chromosomal segment 16p11.2 — previously reported as a key autism region — are seen in people with developmental delays and speech and behavioral problems, but not necessarily autism. That’s the finding from two large studies published last week of people carrying these rare genetic variations.

A newer version of the psychiatric manual may expand the definition of autism, folding in Asperger syndrome and pervasive developmental disorder not otherwise specified.

The news yesterday was hard to miss: 1 in every 100 children apparently has autism, according to two new studies.

It took 50 years for scientists to develop instruments reliable enough to be considered the gold standards for diagnosing autism. Autism has always been around, but it was not until the mid-1940s that Leo Kanner in the United States and Hans Asperger in Austria, both physicians, independently described children with what we now recognize as autism.

Sitting on a sofa in his office at the Yale Child Study Center, Ami Klin plays a movie clip on a tiny laptop. The clip stars a younger Klin, with larger glasses but the same easy smile, vying for the attention of a young girl with autism. His face inches from hers, he speaks in a warm, animated voice. But the girl never looks from the toy blocks in her hands. Suddenly, she spots an orange M&M in the far corner of the room and scoots after it.

In the past two weeks, autism researchers and advocacy groups have been agog with news that autism could be linked to an extremely rare group of metabolic diseases.