Dr. Ernst Lanzer

"Rat Man" was the nickname given by Sigmund Freud to a patient whose "case history" was published as Bemerkungen über einen Fall von Zwangsneurose ["Notes Upon a Case of Obsessional Neurosis"] (1909). This was the second of six case histories that Freud published, and the first in which he claimed that the patient had been cured by psychoanalysis.

The nickname derives from the fact that among the patient's many compulsions was an obsession with nightmarish fantasies about rats.

To protect the anonymity of patients, psychoanalytic case studies usually withheld or disguised the names of the individuals concerned. Recent researchers have decided that the "Rat Man" was in fact a lawyer named Ernst Lanzer (1878–1914)—though many other sources maintain that the man's name was Paul Lorenz.

IKG Geburtenbuch:

https://familysearch.org/pal:/MM9.3.1/TH-1971-25807-5747-5?cc=20283...

https://www.encyclopedia.com/psychology/dictionaries-thesauruses-pi...

https://en.wikipedia.org/wiki/Rat_Man