The American Psychiatric Association's board of trustees has approved the fifth edition of its influential diagnostic manual, dubbed DSM-5, the group announced Saturday.

The board vote is the last step before the manual is formally released at the APA's annual meeting next May. The association's Diagnostic and Statistical Manual of Mental Disorders was last revised in 1994; that edition is known colloquially as DSM-IV.

According to an APA statement, changes include an end to the system of "axes" used to class diagnoses into broad groups, and an associated restructuring of diagnostic groups to bring disorders thought to be biologically related under the same headings.

Also, many of the diagnostic criteria will now include so-called dimensional assessments to indicate severity of symptoms.

Specific language in DSM-5 was not immediately released, and probably won't be until the formal unveiling in May. Detailed criteria that had been published on the APA's DSM5.org website for public review and comment have now been removed.

However, the statement released Saturday indicated that the manual will include many of the most controversial of the proposed changes from DSM-IV.

They included removal of the "bereavement exclusion" in the major depression section. In DSM-IV, a diagnosis of depression could not be made in patients who had suffered the death of a loved one until two months had elapsed. Under DSM-5, such patients may be called clinically depressed sooner, although the criteria will include advice to clinicians about distinguishing normal grief from depression that should be treated.

DSM-5 will also add a diagnosis of "disruptive mood dysregulation disorder" for children older than 6 who show frequent bursts of anger along with chronic irritability.

In fact, it appeared from the statement announcing the approval that most of the changes from DSM-IV discussed at the APA's 2012 meeting were ratified by the board.

One outside interest group lost no time in reacting to the APA's announcement.

In a statement issued barely an hour after the APA's release, the chief science officer for Autism Speaks, Geraldine Dawson, PhD, said the group remained "concerned about the impact of the new DSM-5 criteria when they are used in real world settings. The field trials are somewhat reassuring that the criteria are working well, but these trials are based on a relatively small number of children. We still have very little information about the impact of the DSM-5 on diagnosis of autism spectrum disorder in young children and adults."

Dawson said the group believes it is "crucial" that diagnosis and access to services be monitored once DSM-5 is in use. "We want to make sure that no one is excluded from obtaining a diagnosis and accessing services who needs them."

In fact, some of the changes proposed for DSM-5 would loosen the criteria, as the head of the APA's work group on autism spectrum disorders explained at the 2012 APA meeting.

Susan Swedo, MD, of the National Institute of Mental Health, noted that the work group was seeking to drop an age-based exclusion in the DSM-IV criteria.

The other major change proposed for DSM-5 was a reorganization that would collapse a number of autism-related conditions treated as separate disorders in DSM-IV into a single "autism spectrum disorder" category.

Those changes were blasted by some in the autism advocacy community, but Swedo argued that the criticisms were unfounded.

In announcing the APA board's action, James H. Scully, MD, medical director and chief executive officer of APA, said, "At every step of development, we have worked to make the process as open and independent as possible. The level of transparency we have strived for is not seen in any other area of medicine."

The group also noted that more than 160 clinicians and researchers had worked to develop DSM-5, with help from hundreds of other clinical investigators as well as thousands of comments from health professionals and the general public offered during open-comment periods.