LSD, MDMA, PCP, magic mushrooms (psilocybin), peyote (mescaline)—these are all types of hallucinogens, a class of drugs that "alters a person’s awareness of their surroundings as well as their own thoughts and feelings." Also known as psychedelics, sometimes these drugs are extracted from plants, and sometimes they’re synthetic, or man-made.

Historically, some of these drugs have been used medicinally as well as ceremonially in indigenous cultures around the globe. Today, there’s growing evidence that the medical use of hallucinogens can have therapeutic effects. But using them recreationally can be an intense experience, and there are short-term and long-term health risks.

What does it feel like to use hallucinogens?

When used recreationally, these drugs distort your perception of reality, often through vivid hallucinations. They alter your thoughts and feelings and can cause sensory experiences, like brightened colors or a sense of movement in stationary objects. Some people who’ve used hallucinogens report having experiences that are spiritual or bring emotional healing.

These drugs can also cause unpleasant short-term side effects, including nausea, anxiety, and increased heart rate. In high doses, some of these drugs can cause seizures, panic, an inability to move, and mood swings. Long-term use of some hallucinogens can cause speech problems, memory loss, or suicidal thoughts. In rare cases, persistent psychosis and Hallucinogen Persisting Perception Disorder, more often known as "flashbacks," can occur.

Are there effective medical uses for hallucinogens?

Researchers are working to answer that now. Dr. Roland R. Griffiths, creator of the psilocybin research program at Johns Hopkins University, has found that these drugs have the potential to treat conditions like Alzheimer’s, depression, and even addiction. Ketamine is also increasingly being explored as a treatment for depression and post-traumatic stress disorder (PTSD). As with any medicinal substance use, it's important to remember that using these drugs as treatments for an illness should happen under a doctor's supervision and care.

Early results are promising, but more research is needed to determine the efficacy and side effects of these treatments.

Can you overdose on hallucinogens?

It depends on the drug. When someone has taken too large a dose of psilocybin, for example, they may experience intense unpleasant feelings, but their life is not necessarily in danger as a result.

Too large a dose of PCP can cause seizures or even death.

However, too large a dose of a hallucinogen like PCP can cause more serious medical consequences, like seizures or even death.

Due to the mind-altering nature of these drugs, using them also brings the risk that a person will do something dangerous that they wouldn’t normally do, like jump from a high ledge or act on a suicidal thought.

How can risks be reduced when using hallucinogens?

• Make sure you’re in a safe environment with people you trust
• Don’t mix with other substances, like marijuana or alcohol—this can cause unpredictable complications
• Stay out of the driver’s seat

How can an addiction to hallucinogens be treated?

Just like with any other substance, it’s possible to develop an addiction to hallucinogens.

Treatment for this use disorder is trickier: There are currently no known medications to treat an addiction to hallucinogens, and more research is needed to determine if behavioral therapies are effective.

Generally speaking, addiction is a treatable illness. If you or a loved one needs help with hallucinogen use, start by making an appointment with a primary care doctor, who can conduct an assessment and make referrals.