2011 marked the 20th anniversary of the first prescription written by a Psychologist.

The first prescription was written by a Psychologist that was part of the Department of Defense's Psychopharmacological Demonstration Project (PDP).  The PDP was a training program designed to train Military Psychologists and test whether Psychologists could be trained to be safe effective prescribers.  The PDP faced strong opposition.  The program was eventually terminated but not before it proved the concept that Psychologists could be trained to be safe effective prescribers.  By the end of the PDP program it had established a successful training model for prescribing psychologists, a model that still serves as the basis of training today.  In the final evaluation of the PDP program undertaken by the American College of Neuropsychopharmacology in 1998 concluded "PDP graduates have performed and are performing safely and effectively as prescribing psychologists."  A further testimony to the success and acceptance of the PDP concept is that all branches of the US armed forces now have Prescribing Psychologists.   

RxP expanded beyond the military.  In 2002 New Mexico passed legislation to grant prescriptive authority to specially trained Psychologists.  Louisiana followed suit in 2004.

Psychologists are also prescribing in the Indian Health Services which is part of the Public Health Agency tasked by the federal government to provide health services to over 1.8 million American Indians and Alaskan Natives.

In the more than

20 years since the first prescription was written by a Psychologist hundreds of thousands of prescriptions have been written by Psychologists and to date there is no evidence that any major adverse event has resulted from a prescription written by a Psychologist.