LSD is a hallucinogenic drug developed in 1938 that distorts the user's sense of time and identity. It was used in the 1940s to treat mental illnesses but causes unpredictable effects like delusions, hallucinations, panic attacks and impaired judgment. LSD is typically sold as liquid on blotter paper, gelatin squares or sugar cubes with a dose of 25 micrograms, though only 1% reaches the brain. Effects can last 8-12 hours and include altered visual perception, emotions and thought patterns.