These methods were exactly the same as being developed and used by the CIA under the ARTICHOKE program which ran from Aug 20, 1951 to Apr 13, 1953. The program however, had both pro and antecedents and continued in one form or another into the 21st century wars in the Middle East.
According to the wikipedia entry for this project ARTICHOKE was a mind control program that gathered information together with the intelligence divisions of the Army, Navy, Air Force, and FBI. In addition, the scope of the project was outlined in a memo dated January 1952 that stated, "Can we get control of an individual to the point where he will do our bidding against his will and even against fundamental laws of nature, such as self-preservation?" Experiments were carried out "on the weaker and less intelligent" especially "homosexuals, racial minorities and military prisoners."
So... prolonged questioning... lack of sleep...threats to friends or relatives...drugs... hypnosis... combined to create fatigue and apprehension bordering on mental collapse...
With the exception of prolonged questioning, this sounds a lot like what happened to Jack Ruby.