"This is the saddest moment in my 45-year career as a psychiatrist..." Dr. Allen Frances wrote this in a December blog post on the Psychology Today website. The reason was the approval by the American Psychiatric Association (APA) of the new edition of psychiatry’s bible – Diagnostic and Statistical Manual of Mental Disorders, or DSM – the handbook that doctors and psychotherapists worldwide use to determine mental illness.

In May, DSM-5 – the first revised edition since 1994 – is due to be published in the United States. And Allen Frances’s verdict about it has clout – he was the chair of the DSM-4 Task Force. His advice to clinicians, the press and the general public is to remain skeptical about DSM-5: “don’t follow it blindly.”

Over 1,500 experts from 39 countries have spent the last 14 years working on improving the classifications so that superfluous or imprecise diagnoses can be avoided and with them the wrong medication or therapy.

The new edition features new disorders, such Minor Neurocognitive Disorder – that can presage dementia, or eating and gambling addictions that for the first time link addiction to other sources than mind altering substances.

Other disorders have been left out – like Rett Syndrome, a neurodevelopmental disorder. The diagnostic criteria for many other illnesses have been changed. Autism for example will no longer be listed as a spectrum of many separate conditions so that, as of May, Asperger’s Syndrome will no longer exist.

All of this is the result of a great deal of hard work and discussion on the part of contributing experts, resulting in many different drafts of the manual before the APA signed off on the latest edition. The subject of sex addiction was particularly controversial – at first it was going to be included among behavioral addictions, then as a whole new illness called hypersexual disorder, and finally it was dropped because scientific evidence to support it was too slim.

According to the APA, the number of mental illnesses in the new edition remains the same and there are only a few fundamental changes. However, critics maintain that some diagnoses have been watered down and that changes are not based on sufficient scientific evidence.

These experts fear that DSM-5 will turn many healthy individuals into patients, and will limit treatment of certain diagnoses like autism. Fred Volkmar of Yale University estimates that only 60% of those who would get an autism diagnosis today will get it in the future.

Frances agrees that with the exception of autism, all the changes in the new edition will turn the “current diagnostic inflation into diagnostic hyperinflation” – something that could have dire consequences, given the global importance of the manual.

Temper tantrums as mental disorder

"The DSM is the standard reference book worldwide; research and treatments are based on it. It is also used as a reference in court cases and by insurance companies," says Winfried Rief of the University of Marburg, one of the experts involved in producing DSM-5. German doctors also use the World Health Organization (WHO) International Classification of Diseases, the present edition of which (ICD-10) is due for an overhaul in 2015.

Hans-Ulrich Wittchen of Dresden’s University of Technology, who also worked on DSM-5, says he does not believe the new version will lead to increased numbers of diagnoses. "No changes are to be expected because the criteria were only changed marginally," he explains, adding that "even the new disorders will most likely not impact the total number of patients because most patients suffering from conditions added to DSM-5 usually have other disturbances listed in earlier editions."

But Frances is adamant that the new edition is going to bring with it a dramatic rise in the number of mental illness diagnoses, particularly – as “painful experience” with previous editions has shown – if anything in the diagnostic system is abused and turned into a “fad.”

The conflict demonstrates just how difficult it is to classify mental illness. A case in point is what DSM-5 lists as "disruptive mood dysregulation disorder" in children. On Frances’s list of the ten worst changes from the previous edition, this condition is ranked number one.

According to the APA, this diagnosis applies to children who display disruptive patterns three or more times a week for at least a year, and it is supposed to help check over-diagnosis and over-treatment of bipolar disorder in children. But Frances charges that what it amounts to is turning “temper tantrums into a mental disorder.” His own book, SAVING NORMAL: The Battle at the Boundary of Psychiatryis due out around the same time as DSM-5.

What is clear is that there are no definitive answers – or answers that will satisfy everyone. Says Wittchen: "Diagnostics never end – many problems have yet to be resolved because we don’t yet know enough about how the brain works. Breakthroughs in neurobiological research could mean a whole new set of diagnoses. And then we get to start from scratch.”