The CIA started using chemicals in the late 1950's to control a person's behavior and mind. Since the creation of the CIA in the late 1940's their main priority was to be able to read a person's thought processes to determine enemy or friend.
Project MKULTRA has shown that they did not care who they hurt in the process of achieving their goal.
Today science and technology combined allows for mind manipulation and control through many different processes. Using multiple different types of chemicals helps in all mind control applications achieve their objective.
Wikipedia: Mind
https://en.wikipedia.org/wiki/Mind
CIA Project MK-Ultra started in the 1950's testing on US citizens
https://en.wikipedia.org/wiki/MKUltra
Midnight Climax was a subproject of MK-Ultra carried out in the 1950's
https://en.wikipedia.org/wiki/Operation_Midnight_Climax
Research on prisoners still happens today
https://en.wikipedia.org/wiki/Experimentation_on_prisoners
The CIA's Secret Quest For Mind Control: Torture, LSD And A 'Poisoner In Chief'
PRIVATE INSTITUTIONS USED IN CAL EFFORT TO CONTROL BEHAVIOR
What is the Burundanga drug?
https://www.wired.com/story/mind-controller-1/
Neuroscience—and the new weapons of the mind
By Robert Bruner, Filippa Lentzos | October 27, 2017
https://thebulletin.org/2017/10/neuroscience-and-the-new-weapons-of-the-mind/
Scientists manipulate brain cells using a smartphone
https://newsroom.uw.edu/news-releases/scientists-manipulate-brain-cells-using-smartphone
Mind-control device lets people alter genes in mice through power of thought
https://www.theguardian.com/science/2014/nov/11/mind-control-device-alter-genes-mice