Dear Mr. Nunez,
Thank you for posting your request on History Hub!
There is no single repository of patient records, nor are we aware of any requirement that patient records be retained permanently by any organization. Most states require that doctors and other medical institutions retain records for only a limited period of time, and most organizations dispose of these records after the minimal time period has passed. Also, access to patient records is highly restricted under a variety of medical privacy laws. In some cases, records pertaining to state institutions may have been retained by the relevant state archives.
We suggest contacting organizations with a specialized focus on medicine and psychology that may be able to offer advice on your research, such as The University of Akron Cummings Center for the History of Psychology, the American Psychological Association's History of Psychology journal, the U.S. National Library of Medicine (NLM), and the psychology departments of universities.
We hope this is helpful. Best of luck with your research!