From Wikipedia:

Headed by Dr. Sidney Gottlieb, MKULTRA was started on the order of CIA director Allen Dulles on April 13, 1953[5], largely in response to alleged Soviet, Chinese, and North Korean use of mind-control techniques on U.S. prisoners of war in Korea.[6] The CIA wanted to use similar methods on their own captives. The CIA was also interested in being able to manipulate foreign leaders with such techniques[7], and would later invent several schemes to drug Fidel Castro.

In 1964, the project was renamed MKSEARCH. The project attempted to produce a perfect truth drug for use in interrogating suspected Soviet spies during the Cold War, and generally to explore any other possibilities of mind control.

Because most of the MKULTRA records were deliberately destroyed in 1972 by order of the Director at that time, Richard Helms, it is impossible to have a complete understanding of the more than 150 individually funded research projects sponsored by MKULTRA and related CIA programs.