People take hallucinogens for a wide range of reasons: curiosity, spiritual exploration, introspection, therapeutic relief, social bonding, and creative or emotional breakthroughs. Over 30 million people in the United States alone have used a psychedelic at least once, and their motivations span from ancient ritual traditions to modern clinical research into depression and PTSD.
Curiosity and Personal Exploration
The most commonly cited reason for trying a hallucinogen is simple curiosity. People want to know what an altered state of consciousness feels like, and psychedelics deliver an experience dramatically different from everyday perception. Colors may intensify, objects may appear to shift or breathe, and the sense of time can stretch or compress. For many first-time users, the draw is experiential: they want to see for themselves.
Beyond curiosity, many users report seeking introspection. Hallucinogens can produce a heightened sense of self-awareness and emotional clarity that people describe as seeing their lives, habits, or relationships from a completely new angle. This perspective shift is partly why psychedelics have attracted interest from therapists and researchers, but it’s also a primary reason people seek them out on their own.
Spiritual and Mystical Experience
Hallucinogen use for spiritual purposes is arguably older than written history. Archaeologists excavating a cave in southwestern Bolivia discovered a 1,000-year-old ritual bundle belonging to a shaman of the pre-Inca Tiwanaku civilization. Scrapings from the artifacts inside revealed traces of psilocin (the active compound in psychedelic mushrooms), DMT, and several other psychoactive substances. Ritual drug use has been documented in hunter-gatherer cultures across the Americas, Eurasia, Australia, and Africa.
The ancient Greeks held the Eleusinian Mysteries, seasonal religious rites that included drinking a psychoactive preparation called kykeon, which may have contained LSD-like compounds from ergot fungi. The Maya incorporated psychoactive substances into their culture as well. The fourth-century historian Herodotus described Scythian cannabis rituals on the Pontic Steppe, a practice recently confirmed through archaeological analysis of funerary braziers.
These traditions survive today. The Native American Church uses the peyote cactus, which contains mescaline, in all-night prayer ceremonies led by a guide called a “Roadman.” This practice may be as old as 40,000 years. In Amazonian communities, ayahuasca ceremonies are facilitated by a curandero (healer), with days or even weeks of preparation before drinking the psychedelic brew. In both traditions, the hallucinogen is not the point by itself. It’s a tool used within a structured, communal ritual to help people reframe personal crises or connect with something larger than themselves.
Therapeutic Use and Clinical Research
A growing number of people turn to hallucinogens specifically for mental health relief. The FDA has granted breakthrough therapy status to psilocybin for both treatment-resistant depression (2018) and major depressive disorder (2019), and to MDMA for post-traumatic stress disorder (2017). Clinical trials are currently testing psilocybin for cancer-related anxiety, anorexia, substance use disorders, and chronic pain.
The therapeutic appeal is straightforward: some people with depression, anxiety, or addiction find that a single guided psychedelic session produces lasting emotional shifts that months or years of conventional treatment have not. The experience often involves confronting difficult emotions or memories head-on, but in a state where the brain’s usual defenses are loosened. Patients in clinical trials frequently describe the session as one of the most meaningful experiences of their lives, even when the emotional content was painful.
What Happens in the Brain
Classic psychedelics, whether derived from mushrooms, plants, or synthesized in a lab, all work by activating the same receptor in the brain: a serotonin receptor involved in mood, perception, and cognition. When this receptor is blocked by an antagonist drug, the subjective effects of psilocybin and LSD largely disappear, confirming it as the primary gateway for psychedelic experiences.
One of the most consistent findings in brain imaging research is that psychedelics disrupt the default mode network, a group of interconnected brain regions that are most active when you’re at rest and thinking about yourself: planning, remembering, worrying, ruminating. During a psychedelic experience, connectivity within this network drops significantly, while communication between brain regions that don’t normally talk to each other increases. The result is a brain that operates in a less constrained, more flexible, and less self-referential way. This is what researchers believe underlies the feeling of “ego dissolution,” where the boundary between self and world temporarily softens or disappears.
These changes aren’t always limited to the hours of the trip. Brain imaging of depressed patients has shown reduced default mode network rigidity up to three weeks after a single psilocybin session, suggesting the brain doesn’t simply snap back to its previous patterns.
Social Connection and Personality Change
Some people use hallucinogens in social settings, particularly at festivals, raves, or small gatherings, to feel more connected with others. Research supports this: psychedelic experiences in group settings are associated with stronger social bonding and increased cooperative behavior. In one study, people who had transformative, awe-inspiring experiences at raves showed greater bonding to fellow participants and more prosocial behavior in economic games where they could choose to help others at a cost to themselves.
There’s also evidence that psychedelic use produces lasting personality shifts. Double-blind trials have found that mystical experiences during psychedelic sessions lead to significant increases in trait openness, a personality dimension that encompasses curiosity, creativity, and receptiveness to new ideas. This is notable because personality traits are typically considered stable in adulthood. The increase in openness was still measurable a full year after a single session.
Microdosing for Daily Function
A more recent trend is microdosing: taking roughly one-tenth of a full psychedelic dose every few days, with the goal of subtle improvements in mood, creativity, or focus rather than a full hallucinatory experience. Advocates claim it sharpens thinking and reduces anxiety without producing any perceptual distortions.
The controlled research, however, tells a more complicated story. A systematic review and meta-analysis of microdosing studies found a significant decrease in cognitive control, with no detectable improvements in other cognitive areas. This aligns with what scientists know about how psychedelics work at the neural level: they reduce the brain’s top-down filtering, which may feel like mental fluidity or creativity but actually measurably impairs the ability to stay focused and override impulses. Whether that tradeoff is useful likely depends on what someone is trying to accomplish.
Physical Effects During Use
Hallucinogens are not purely mental experiences. They produce measurable physical changes. LSD at moderate doses raises blood pressure, heart rate, and body temperature, with effects peaking about an hour after ingestion and returning to normal within roughly 12 hours. Psilocybin increases blood pressure at hallucinogenic doses, though it does not appear to cause heart rhythm abnormalities even at high doses. DMT, whether injected or consumed as ayahuasca, raises heart rate, blood pressure, body temperature, and stress hormone levels. Pupil dilation is common across all classic psychedelics.
These cardiovascular effects are generally mild and temporary in healthy people, but they can be significant for anyone with heart conditions or high blood pressure.
Risks and Unwanted Effects
The most widely discussed acute risk is a “bad trip,” an experience dominated by fear, paranoia, or confusion rather than insight or wonder. Set (your mindset going in) and setting (the physical and social environment) heavily influence whether an experience turns distressing. This is one reason indigenous traditions and modern clinical protocols both emphasize preparation, a trusted guide, and a safe environment.
A less common but more persistent risk is hallucinogen persisting perception disorder, or HPPD, which affects an estimated 4% to 4.5% of people with a history of hallucinogen use. HPPD involves ongoing visual disturbances after the drug has worn off: geometric patterns, flashes of color, false perceptions of movement, or halos around objects. For most people these symptoms are mild, but for some they can be distressing and long-lasting.
Psychedelics are not considered physically addictive. They don’t produce compulsive drug-seeking behavior, and tolerance builds so rapidly that taking the same dose two days in a row produces dramatically weaker effects. The risks are primarily psychological: triggering latent psychiatric conditions, worsening anxiety disorders, or producing traumatic experiences that linger emotionally long after the drug clears the system.