Ex Scientology Kids

Hubbard wrote Dianetics after Freud and more specifically Josef Breur tried to treat Anna O. She was diagnosed with Hysteria when her father was dieing. Sometimes she would suffer paralysis of random parts of her body, hallucinate or forget languages (she spoke several). It was her who came up with the idea that previous experiences may cause later trauma, which Breur and Freud then expanded to explain all disorders.

At the Hubbard was in the military "shell-shock" was a well known symptom of repeated army duty which was assumed to be caused by the noise and concussive force explosions have on the body. It was later found out that all traumatic experiences in which the individual has no control and is life threatening may lead to PTSD.

Hubbard likely never encountered PTSD, but shell shock was a common topic which all military people were familiar with.