Which of the following is classified as a hallucinogen in the examples?

• A. LSD
• B. Ketamine
• C. Heroin
• D. Alcohol

Answer: (A)

Hallucinogens are drugs that mainly alter perception, mood, and thinking, often producing vivid sensory distortions or hallucinations. LSD is a classic example of a hallucinogen. It works primarily on serotonin receptors in the brain, especially 5-HT2A, which shifts how sensory information is processed. This can lead to visual distortions, intensified colors, geometric patterns, time perception changes, and unusual thoughts or emotions. The effects can last several hours and vary with dose, environment, and mindset. Ketamine, while it can cause perceptual changes, is a dissociative anesthetic and is categorized separately from classic hallucinogens. Heroin is an opioid depressant, and alcohol is a depressant that slows brain function. So LSD best fits the hallucinogen category.