Answer:

LSD

Answer	Crossword Clue
LSD	It greatly improves Animal Collective records
LSD	Requirement to enjoy prog rock, they say
LSD	Brit. monetary system

LSD	Hallucinogen
LSD	Acid
LSD	Hallucinogen, for short
LSD	Hallucinogen letters
LSD	"Acid"
LSD	1960s hallucinogen
LSD	Trip-taking cause
LSD	Cause of a trip

LSD	Trip facilitator, for short
LSD	Blotter-paper application
LSD	Drug derived from ergot
LSD	Drug advocated by Leary
LSD	Drug advocated by Timothy Leary
LSD	Long trips are taken on it
LSD	Something you might trip on
LSD	A raver might drop it

LSD	"Turn on, tune in, drop out" substance
LSD	'60s drug
LSD	People tripped on it at Woodstock
LSD	"Acid" used in some trips
LSD	'60s hallucinogen
LSD	Acid, so to speak
LSD	Timothy Leary drug
LSD	'60s "trip" inducer

LSD	'60s hallucinogenic
LSD	It was dropped in the '60s
LSD	Leary's drug
LSD	Timothy Leary turn-on
LSD	Trip-taker's agent?
LSD	Dr. Leary used it on some trips
LSD	Leary tripped on it
LSD	"Dropped" substance

LSD	'60s trip starter, initially
LSD	'60s tripper's substance
LSD	Leary's turn-on
LSD	Trip producer?
LSD	Drug used in old CIA mind-control experiments