CHICAGO -- The guidebook that U.S. psychiatrists use to diagnose mental illness is getting its first major update in almost 20 years.

The nation's most influential psychiatry group on Saturday approved scores of revisions 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.

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