PLEASE NOTE: AMERICAN PSYCHIATRIC PUBLISHING HAS SINCE REMOVED THE LINKS TO THE PDF VERSIONS OF PREVIOUS DSMs AND PUT THEM BEHIND A PASSWORD PROTECTED WALL. WE ARE SORRY FOR ANY INCONVENIENCE DUE TO THIS CHANGE.
On their website, American Psychiatric Publishing, Inc. includes electronic versions of the Diagnostic and Statistical Manual of Mental Disorders I, II, III, IIIR, and IV. Each of the books are available in a PDF format.
This provides a perfect opportunity to see how the various disorders names, descriptions, and symptom patterns have changes over the years. Below I've included the links to each of the past DSMs.
DSM-I in PDF
DSM-II in PDF
DSM-III in PDF
DSM-III-R in PDF
DSM-IV in PDF