A flashback is an erratic, spontaneous reenactment of a specific part of an LSD trip that happens after the first effects of the drug wear off. Reliving initial visual or emotional sensations while high on LSD results in reliving the same feelings. Although they sometimes only last a few seconds or minutes, flashbacks can occur repeatedly. LSD may exacerbate anxiety or depression or release underlying psychosis in certain individuals. The highest quality 1-propionyl-lysergic acid ...