The main reason for the changes is due to advances in research and knowledge since the DSM-IV (psychiatric manual for diagnosing mental disorders) was published in 1994. For a start, there's no strong body of research evidence distinguishing High-functioning Autism from Aspergers. Even Tony Attwood says that the only difference between the two is how they are spelled.
The use of the term Autism Spectrum Disorder isn't new, it's been prevalent for some time now, used as an umbrella term by professionals the world over. Meanwhile, there are many people diagnosed with Asperger's ("Aspies") who feel that removal of their label is tantamount to stealing their identity. My son says that no matter what, he will always be an Aspie. But by the same token, he just as readily identifies with the title Autism because we have used the two terms equally in our household. Asperger's is a form of Autism, that has always been true, so we have used the language accordingly.
There is some serious concern that many people with less severely debilitating forms of autism, who might have been diagnosed under the DSM-IV, will no longer be diagnosable under the DSM-V criteria. This concern is based primarily on one study, and I have read some responses to that study which suggest it doesn't offer enough evidence to prove that point. However it's still a valid thing to be concerned about, especially if people are going to find themselves without supports and medical assistance when they truly need it.
I am still working out my own views on all of this, so I can't express a solid opinion just yet. Just as there was with ADHD, the chatter out there in the world is that Autism is being overly diagnosed at the moment (whether or not I agree with that chatter is also yet to be determined). I'm also tired of hearing about the (in my opinion fictional) "epidemic" (that's a whole other rant). So while I hesitate to state this in black and white, maybe it's possible that some people who wouldn't be diagnosed under the new criteria, shouldn't be diagnosed anyway. Then again, if people with legitimate need are left out in the cold because of poorly written criteria, that's obviously very bad.
Our pediatrician has made it clear that my son would easily still be diagnosed with Autism under the new criteria. But then he started out as profoundly affected and only after many years of sheer bloody-minded effort from many people since he was 12 months old, he then fit the Asperger's criteria, with a few additional quirks/challenges thrown in. So maybe there are other kids who find life a little less challenging than he does, but who still need help, who might not be eligible under the new criteria. That remains to be seen, but I hope that's not the end result.
I do believe the re-labelling is an important step, at least on a psychosocial level. Too long have invisible lines been drawn between different groups in the Autism community, separating children by their level of functioning, comparing and saying some are "worse off" than others. On the surface it might seem that way, but in fact all people with ASDs deserve acknlowedgement and support on their journey. Such comparison does not help anyone. Too long has this division been used as a weapon in debates about what is needed and what should be done for people with Autism. I believe the labelling will provide greater unity within the Autism communities around the world, as parents and carers as well as those with ASDs all realise they are walking the same difficult path, each with their own complicated obstacles to overcome.
The new diagnostic criteria will be as follows:
Autism Spectrum Disorder
Must meet criteria A, B, C, and D:
A. Persistent deficits in social communication and social interaction across contexts, not accounted for by general developmental delays, and manifest by all 3 of the following:
1. Deficits in social-emotional reciprocity; ranging from abnormal social approach and failure of normal back and forth conversation through reduced sharing of interests, emotions, and affect and response to total lack of initiation of social interaction,
2. Deficits in nonverbal communicative behaviors used for social interaction; ranging from poorly integrated- verbal and nonverbal communication, through abnormalities in eye contact and body-language, or deficits in understanding and use of nonverbal communication, to total lack of facial expression or gestures.
3. Deficits in developing and maintaining relationships, appropriate to developmental level (beyond those with caregivers); ranging from difficulties adjusting behavior to suit different social contexts through difficulties in sharing imaginative play and in making friends to an apparent absence of interest in people
B. Restricted, repetitive patterns of behavior, interests, or activities as manifested by at least two of the following:
1. Stereotyped or repetitive speech, motor movements, or use of objects; (such as simple motor stereotypies, echolalia, repetitive use of objects, or idiosyncratic phrases).
2. Excessive adherence to routines, ritualized patterns of verbal or nonverbal behavior, or excessive resistance to change; (such as motoric rituals, insistence on same route or food, repetitive questioning or extreme distress at small changes).
3. Highly restricted, fixated interests that are abnormal in intensity or focus; (such as strong attachment to or preoccupation with unusual objects, excessively circumscribed or perseverative interests).
4. Hyper-or hypo-reactivity to sensory input or unusual interest in sensory aspects of environment; (such as apparent indifference to pain/heat/cold, adverse response to specific sounds or textures, excessive smelling or touching of objects, fascination with lights or spinning objects).
C. Symptoms must be present in early childhood (but may not become fully manifest until social demands exceed limited capacities)D. Symptoms together limit and impair everyday functioning.
Other interesting articles on this subject: