CHICAGO (December 2, 2012)--The nation's most influential psychiatry group on Saturday approved scores of revisions to the guidebook that psychiatrists use to diagnose mental illness that have been in the works for several years.

Details will come next May when the American Psychiatric Association's fifth diagnostic manual is published.

It’s the first major update in almost 20 years.

Eliminating terms including Asperger's disorder and dyslexia were among the most contentious proposed changes.

Doctors aren't the only ones who rely on the manual.

It's also important for the insurance industry in deciding what treatment to pay for, and it helps schools decide how to allot special education.