I believe the redacted portions of this recently declassified MKUltra document include information about Charles E Dederich and his founding of the Synanon cult literally three days prior to it's writing.
https://www.maryferrell.org/showDoc.html?docId=144938#relPageId=148&tab=pageDederich worked for a "military defense contractor" in his early years before starting Synanon. There are also stories of LSD being given out freely to Synanon members as part of their interrogations. Ultimately, Synanon was the perfect medical control group for experimentation. They all ate the same diets because food was provided by the cult, they were made of of all races ages and genders, they all underwent the exact same exercise regimens, etc. They were primarily addicts and released prisoners, so they were exactly the sort of people the government would have been willing to experiment on in the early 1960's. It is my opinion that those people who were victims of these MK-ultra programs in the 1960's then neurotically acted out the abuse they had suffered onto others, who then imprinted others, etc. This basically had a cascading effect and is a true sociological phenomenon that therefore can't be isolated to just one person. This sick phenomenon is common to a small population of people, and that makes it all the more insidious and all the more harmful to the ideas of human freedom and liberty. We may never know if the above MK-Ultra document actually references Synanon or if it references some similar cult program, but what is clear in my opinion from the evidence is that Synanon more than any other program was basically just a dry run of communist brainwashing tactics on Americans. Whether Dederich did it for national defense purposes, or just learned of these tactics and then decided to implement it because he was a power hungry sociopath, we will never know. But it makes sense that the government would be interested in researching interrogation, and Synanon would have been literally the best test pool I could have thought of if I was a deep state operative in the early 1960's.
This video about North Korean communist brainwashing tactics produced in the mid nineteen fifties at around the time of Synanon's founding by the US War Dept. seems like it describes many of the tactics used in Synanon. The below video proves that our government had a very real interest in doing real world testing on civilian Americans to more fully understand the effects of these sorts of brainwashing tactics. These experiments were likely considered essential national security projects.
https://www.youtube.com/watch?v=_yVzQB9y3GE