King who has been working on revising the autism diagnosis criteria since 2007 and also treats children with autism and other developmental disorders as the director of the Seattle Children's Autism Center.

He believes the new diagnostic criteria could be more inclusive and lead to more children being diagnosed with ASD. King says there are at least three big changes that could potentially open up the door for more (not less) children being diagnosed with autism:

1. A patient's history.

If, for instance, a teenager shows social impairments and sensory sensitivities (criteria for autism), but at the time of evaluation no longer lines up toys and is preoccupied with spinning wheels (other signs of autism), this history of repetitive behavior could be included to make an autism diagnosis. That's not possible under DSM-IV criteria.

2. Softening the criteria of the age of onset of symptoms.

Under the current guidelines for diagnosing a child with autism, symptoms have to occur before age 3. However, in some children, the impairment from autism may not be seen until a later age, particularly in people on the higher functioning end of the autism spectrum. The new criteria allow for older children to meet diagnostic criteria for autism.

3. Range of severity of symptoms.

Under the current DSM, in order to be diagnosed with autism, a child had to meet a certain amount of criteria at a certain level of severity.

"We offer up a range of severity of deficit that goes from abnormal social approach and failure of normal back-and-forth conversation all the way through complete lack of social communication. Everything in between is left to the clinician to be able to identify and work with," King says.

In the DSM-5, clinicians will not only have the criteria to refer to, they will be given actual examples of how children display these diagnostic criteria.

Dr. Max Wiznitzer, a pediatric neurologist and autism expert from Rainbow Babies and Children's Hospital in Cleveland, Ohio, says providing examples is one of the key changes in the DSM-5.

Explaining the criteria and providing examples will help minimize any potential misinterpretation and misdiagnosis, according to Wiznitzer.

"Part of the problem we've had with the application of DSM-IV diagnostic criteria is that people don't understand the underpinning of each of the diagnostic criteria and interpret them in a superficial manner."

This can lead to children incorrectly being diagnosed with autism as opposed to ADHD or other social or behavioral disorders.

Wiznitzer was not part of the group tasked with reviewing and revising the autism criteria. He believes that by better applying the new autism criteria, it could lead do some people not getting the ASD label in the first place, but those who already have autism will not lose their diagnosis.

Going forward in his practice, King says he will use the new criteria, but he's not going to retrospectively rediagnose patients. So in his practice, nobody will lose their autism diagnosis.

"We have people waiting months for an autism diagnosis," King says. "There's no way and no place for clogging the diagnostic wait lists for people to get rediagnosed for administrative purposes."

He hopes the APA and other organizations with provide formal recommendations that provide instructions for clinicians to only re-evaluate a patient diagnosed with an autism spectrum disorder under the current definition, if there's a clinical reason to so.

According to a statement from the APA, the new manual will include approximately the same number of disorders as were included in DSM-IV.

"This goes against the trend from other areas of medicine that increase the number of diagnoses annually," Kupfer said in the statement.