What class of drugs is known to cause altered perceptions and hallucinations?

Hallucinogens are a class of drugs specifically known for their ability to alter perceptions and induce hallucinations. These substances work primarily by affecting the serotonin receptors in the brain, leading to changes in mood, consciousness, and sensory perception. Common examples of hallucinogens include LSD (lysergic acid diethylamide), psilocybin (found in certain mushrooms), and mescaline.

Unlike analgesics, which are designed to relieve pain; stimulants, which enhance alertness and energy; and depressants, which slow down central nervous system functions, hallucinogens distinctly create profound alterations in sensory processing and perception. This unique capability to induce altered states of consciousness sets hallucinogens apart from other classes of drugs, making them particularly noteworthy in discussions of mental and sensory experiences.