The Diagnostic and Statistical Manual of Psychiatry, published by the American Psychiatric Association, has come under fire recently because of its controversial decision to drop Asperger’s syndrome from its newest edition (DSM-V), which will be published in May 2013.

Instead, Asperger’s will be lumped into a general umbrella term of “autism spectrum disorder.”

This means people with Asperger’s, a mild, but high-functioning type of autism, may lose out on the services and treatments they need to function within society.

People who knew family of shooter, Adam Lanza, who murdered 20 children and six staff at Sandy Hook Elementary School in Newtown, Conn., Friday, have said he suffered from Asperger’s.

“It’s important to note – even if he did have Asperger’s, which has not yet been confirmed – this condition would not cause him to commit a horrible act of violence alone,” said Dr. Keith Ablow, a forensic psychiatrist a member of the Fox News Medical A-Team.

Another set of psychiatric symptoms have to also be involved, added Ablow, who never treated Lanza.

Related: Could new psychiatric guidelines change the standards for autism diagnosis?

“Children with Asperger’s may not feel connected to others, and may be more vulnerable to other psychiatric disorders. It is also possible that Asperger’s (if he had it) was a misdiagnosis, and he had something else.”

According to the Mayo Clinic, the core issues for children with autism include problems with social interaction, language and behavior.

Related: What is Asperger's?

Ablow said the DSM is basically a “bible” of conditions psychiatrists use to diagnose their patients and, to a great extent, determine what treatments would benefit them. The DSM also has extremely important implications for what kinds of psychiatric problems insurers will cover, and even which ones schools and employers will consider disabilities.

The APA said in a statement earlier this month that the decision to remove Asperger’s from the DSM-V, is to “help more accurately and consistently diagnose children with autism.”

There are other changes to the new DSM as well, including adding entries for new disorders, like hoarding and disruptive mood dysregulation disorder (which refers to frequent temper tantrums). Dyslexia, a learning disorder that affects a person’s ability to read, will also be removed.

Ablow, as well as other distinguished psychiatrists, has disagreed with the APA’s decision from the very beginning.

“This contradicts previous studies that have found 45 percent or more of the patients now considered autistic would no longer be diagnosed as such,” Ablow wrote in a previous FoxNews.com article.

Ablow continued to say that psychiatric researchers “apparently differ by more than 400 percent in their estimates of how many patients will no longer be considered autistic,” and so for the millions of Asperger’s patients who have already been diagnosed, may be taken away from them.

“Medical specialties—psychiatry included—should not be in the habit of shifting their diagnoses every time a new diagnostic manual is published by its trade guild,” Ablow told FoxNews.com. “Rather than the pace of discovery, it could be argued that what is shifting is the way organized psychiatry eyes third-party reimbursement or keys its diagnoses to match up with available medications.”

Dr. Manny Alvarez, senior managing health editor of FoxNews.com, said one of the main differences between Asperger’s and autism is there is no speech delay in Asperger’s, but individuals with the condition may not be able to pick up on subtleties like humor or sarcasm.

The Autism Society states that while children with autism may seem uninterested in social interaction, those with Asperger's typically want to fit in and interact with others - but are incapable of knowing how to do so.

Individuals with Asperger’s usually have above-average intelligence, Alvarez added.

Alvarez noted that the removal of Asperger’s from the DSM-V could diminish early intervention for these people, which “is key to mainstream treatment.”

In a recent blog, Dr. Allen Frances, professor emeritus at Duke University, and the chairman of the DSM-IV task force, said clinical trials that supposedly determine whether the new DSM-V is a good and accurate guide “have been pure disaster from start to finish.”

Frances accused the APA of having “lost its competence and credibility,” saying the trials were a “fiasco.”

Click to learn more about autism spectrum disorder and Asperger's from the Autism Society and AspergerSyndrome.org.