Already, the APA has come under fire from critics and advocacy groups for the changes it has flagged, with some airing fears of its creating over-diagnosis and others outraged that some reclassified disorders could become perceived as less serious.
Disorders being added or changed include sex addiction, eating disorders, stress from bereavement, hoarding, premenstrual pain and depression, and hypochondriasis - now to be referred to as "Illness Anxiety Disorder".
Children who have multiple or unusually violent tantrums may be diagnosed as DMDD, or disruptive mood dysregulation disorder, a step which has drawn inevitable criticism.
Another controversial example is the referencing overhaul of Asperger's.
After its addition to the last DSM in 2000 led to a surge in research and shed new light on the condition, "Asperger's syndrome" is being written out of the new manual, with its symptoms to be reclassified under the new "autism spectrum disorder".
Lori Sherry of the US-based Asperger Syndrome Education Network told the New York Times the move could be a "big step backward", leaving children with Asperger's without the support and services they need.
Writing in the Guardian, psychology academic and "proud Aspie" Joshua Muggleton said he came to support the change.
But he feared the term could die out even within the next decade, and expected the reclassification would also be repeated in the next edition of the International Classification of Diseases (ICD) that is used by many UK practitioners.
For some people in the dark over serious issues they were suffering, the DSM-5 could provide light.
Victoria University associate professor of psychology Marc Wilson said: "It will aid some people experiencing psychological distress to receive a diagnosis that helps them understand what they're experiencing, and it is up to the profession to educate the public about the risks of stigmatisation ..."
"It may be that people for whom there wasn't previously support because they didn't experience something recognised as a diagnosis, may find that there will now be support because they are suddenly legitimate."
In some cases, Professor Wilson said, this would extend to research.
It was unclear what effect the re-write would have in New Zealand, he said.
"Ultimately, many practitioners won't change much of what they already do - you don't need a tinkered set of criteria for depression because you already know depression when you see it."
The DSM-5
What is it?
Published by the American Psychiatric Association and the US National Institutes of Health, the Diagnostic and Statistical Manual of Mental Disorders aims to provide a common vocabulary and understanding among mental health practitioners. The upcoming fifth revision, the DSM-5, updates the last manual published in 2000.
What are the changes?
Full descriptions will be revealed when the manual is published in May, but major additions and omissions include the reclassification of Asperger's syndrome, its symptoms to come under the new bracket of "autism spectrum disorder". The "adjustment disorder" category will soon officially recognise high levels of stress due to bereavement, "illness anxiety disorder" recognises severe concern about a suspected illness, while the term "gender identity disorder" for those who believe they were born the wrong gender will be destigmatised with the name "gender dysphoria". A change to "hypoactive sexual desire disorder" would make this for men only, "premenstrual dysphoric disorder" covers symptoms ranging from anxiety and depression to weight gain and muscle pain, and children with unusually bad temper tantrums would be diagnosed as having DMDD - disruptive mood dysregulation disorder. Also covered are binge-eating disorder, hoarding disorder and skin-picking.
What impacts will they have?
Reclassifications of disorders could affect everything from the amount of research into specific areas and awareness, to compensation and prescriptions. While the DSM-5 is designed for US use, it casts its influence around the world.
