For LSD, What A Long Strange Trip It's Been

"The next day, he writes, 'A sensation of well-being and renewed life flowed through me... everything glistened and sparkled in a fresh light.'"

"LSD seems to shut off certain controls in the brain, allowing signals from one part of the brain to flow unchecked to other regions – particularly the regions that process sensory inputs from the outside world and the regions that define our sense of self. This might explain why LSD can cause hallucinations. It's also why it could plausibly be beneficial to treat depression or anxiety, allowing signals in the brain to bypass pathways that aren't working so well."

"Years of experimentation with LSD both in the laboratory and as a recreational drug suggest that it is physically and mentally safe for healthy individuals. But it can also bring on terrifying hallucinations and sensations, including anxiety and paranoia, especially if people aren't prepared for the experience."

"In the 1950s, the U.S. Army tested LSD's potential to incapacitate enemy soldiers, but it turned out to be too expensive and difficult to deliver by aerosol. The CIA also tested it as tool for mind control by administering it to people, sometimes illegally and without their knowledge or consent, in the notorious Project MKUltra."