By Kent Atkinson of NZPA

Wellington, Feb 25 NZPA - Changes proposed to a key diagnostic handbook mean New Zealanders with relatively mild disorders currently classified as asperger's syndrome will in future be defined as part of a wider grouping of autistic conditions.

The American Psychiatric Association is re-jigging its Diagnostic and Statistical Manual of Mental Disorders (DSM), and says asperger's syndrome should be merged into the wider category of "autism spectrum disorder" (ASD) from May 2013.

Professor Graham Mellsop, of the clinical school at Waikato University, who has shown most NZ psychiatrists rely on the association's definitions, said the American group is influential in the United States, New Zealand, Canada, and Australia.

Experts have argued that autism, like most mental disorders, cannot be seen as an illness such as a cancer that someone either has or doesn't have.

Instead, patients should be seen as being on a continuum -- more like someone with high blood pressure is seen as having a particular level of hypertension.

But moves to have asperger's patients included with other social-interaction disorders has roused controversy overseas, particularly where some high-functioning people with asperger's would rather not see themselves in the same category as those whose autism is so severe that they cannot dress themselves.

Autism New Zealand chief executive Alison Molloy said that there was likely to be a division of opinions of whether the change will be a benefit, but there was already a bias in New Zealand toward all patients coming under the ASD umbrella.

"There is already a view that many people with asperger's syndrome already think of themselves as on a spectrum," she told NZPA.

"For some, there is a decided benefit as it minimises the confusion that seems to exist among the wider population."

The change might also cater for the developmental nature of the disorder, though the different label should not alter the treatment that people received.

ASD was not described as a mental disorder -- rather a developmental disorder -- and the key issue was helping the general public and health professionals to understand the needs of the affected people.

"It may well be that if a single term is better understood there will be more support," said Ms Molloy.

"Many people are simply relieved that there is finally some formal recognition of something they have known for a longtime is different, so the term itself becomes less important.

"Given that there is already a range within most developmental disorders it could perhaps be better expressed in another way as it is with many other disorders."

One "Aspie", Gabrielle Hogg, 22, told NZPA she thought having one grouping for autism, asperger's and PDD-Nos (Pervasive Developmental Disorder Not Otherwise Specified), rett syndrome and childhood disintegrative disorder would be a good move.

"I love the idea of it," she said.

"I also think that it will take a lot of the confusion out."

"At the moment I use the terms asperger's and autism, high-functioning autism, interchangeably because I believe that society needs to wake up to the variety of behaviours that people with ASDs show."

Sometimes people with asperger's also had trouble communicating verbally - it was not just those with severe autism.