Skip to main content

Psilocybin for Mental Health and Addiction: What You Need To Know

psilocybin mushrooms

What is psilocybin?

Psilocybin is a plant chemical that comes from certain types of mushrooms and has been used by indigenous peoples in parts of Mexico and Central America for thousands of years as part of a sacred and ancient tradition. Today, in the United States, psilocybin is considered a psychedelic drug—a type of drug that affects how the brain processes a chemical called serotonin. Common street names for psilocybin are magic mushrooms, mushrooms, or shrooms.

When people take psilocybin, their bodies convert it to psilocin, a chemical with psychoactive properties similar to d-lysergic acid diethylamide (LSD), another classic hallucinogen. The effects of taking psilocybin are hard to predict and can vary widely from person to person. At certain doses, psychedelic drugs, including psilocybin, can change peoples’ moods, thoughts, and perceptions. For example, people who use psilocybin may report feeling strong emotions, seeing vibrant images, reliving vivid memories, or experiencing perceptual changes such as a sense of timelessness or a dissolving of the ego. 

Psilocybin can be consumed by eating fresh or dried psilocybin-containing mushrooms. Although bitter, they can be eaten alone, mixed with food, or made into a tea. Generally, the nonmedical use of psilocybin refers to mushrooms containing psilocybin; synthetic production of psilocybin is complicated and expensive. Some people take psilocybin in “microdoses,” or very small amounts (e.g., one-tenth or one-twentieth of a typical nonclinical dose), because they believe it will improve mental health symptoms such as depression and stress, increase productivity, or reduce pain. However, it is not clear if microdosing is safe or effective.

Research interest in the potential of psychedelic drugs to treat mental health conditions including depression, anxiety, existential distress in serious medical illnesses, post-traumatic stress disorder, and addiction has been growing. The U.S. Food and Drug Administration (FDA) granted “breakthrough therapy” designation to psilocybin-assisted psychotherapy for both major depressive disorder in 2019 and treatment-resistant depression in 2018. The FDA may also grant this designation for treatments for serious or life-threatening conditions where preliminary evidence suggests the treatment may improve the conditions substantially more than other available options.

Who uses psilocybin in the United States?

An annual nationally representative survey on drug use and health reported that 9.68 percent of U.S. adults have used psilocybin at least once in their lifetime, based on data gathered between 2015 and 2018. A breakdown of data from the same survey data (gathered between 2005 and 2019) showed that lifetime psilocybin use was higher among non-Hispanic White adults (11.8 percent) than in Hispanic adults (5.1 percent) or non-Hispanic adults from racial minorities (3.3 percent). A 2022 national survey of substance use in students in grades 8, 10, and 12 reported that 4 percent of adolescents used psychedelics (referred to as “hallucinogens” in the survey) including psilocybin during the past 12 months. 

Is psilocybin safe?

Several concerns have been raised about the safety of psilocybin:

  • A 2022 article for palliative care clinicians states that people should only take psilocybin while under the care of a trained therapist or facilitator. The article notes that the therapist should manage the “set” (the mental state with which the participant enters the experience) and “setting” (the physical environment, support staff, and other features such as music that surround the experience), both of which are essential elements of safety for psychedelic-assisted therapy.
  • Experiences can be unpredictable and may vary depending on how much psilocybin people take and their personality, mood, expectations, and surroundings (e.g., presence of a trained facilitator, type of light and music, indoor or outdoor setting). Other factors that can affect the experience include the person’s health, the type of mushroom, previous experience with similar substances, and combined use with other drugs.
  • Some people have reported unpleasant experiences, sometimes called “bad trips,” involving extreme fear, confusion, or panic.
  • Adverse effects from psilocybin can include increased blood pressure and heart rate, headache, nausea, dizziness, fatigue, poor sleep, anxiety, paranoia, persistent psychosis, and hallucinations.
  • Microdosing psilocybin can lead to insomnia, increased anxiety and depression, poor mood, low energy, physical discomfort (e.g., gastrointestinal symptoms, headache, disrupted senses, temperature dysfunction), poor focus and cognitive functioning, and impaired social skills.
  • Psilocybin is not safe for people with psychotic conditions like schizophrenia, schizoaffective disorder, or severe forms of bipolar disorder and borderline personality disorder.
  • Adulteration of psilocybin with dangerous substances, such as colorless, odorless fentanyl, which is hard to detect, is possible.
  • Psilocybin can cause death at very high doses. Also, some poisonous mushrooms look like psilocybin-containing mushrooms; confusing them could lead to fatal poisoning. 

Is psilocybin effective?

Alcohol Use Disorder

One study has suggested that psilocybin may be helpful for alcohol use disorder. A 2022 study compared the effect of psychotherapy plus two psilocybin sessions to psychotherapy plus placebo in 93 people with moderate alcohol use disorder. Participants who received the psilocybin-assisted psychotherapy had fewer heavy drinking days over 32 weeks, which suggests that psilocybin may be helpful for alcohol use disorder. Most people in the study correctly guessed which therapy they had received, however, and it is not known if the effect from psilocybin lasted longer than 32 weeks. 

Anxiety and Existential Distress in Serious Medical Illnesses

A small amount of research has looked at the use of psilocybin for anxiety and existential distress in serious medical illnesses like advanced cancer. A 2020 analysis of 4 small studies in 117 people, most with life-threatening cancer, concluded that psilocybin combined with psychotherapy may be safe and effective for improving anxiety, depression, and existential distress, as well as quality of life. Because of limitations in the design of the studies and the small number and health status of the people involved, the authors note that the conclusions may have been biased.


A growing body of research has suggested that psilocybin combined with psychotherapy may be helpful for depression in the short and medium term. A 2023 review and analysis of 5 studies in 215 people with depression found that psilocybin treatment combined with psychological support reduced depression symptoms for up to 5 weeks. It is possible that the benefits may last longer than 5 weeks, but there was not enough evidence to be certain. 

A 2021 study in 59 people with depression concluded that psilocybin-assisted psychotherapy did not reduce symptoms better than escitalopram, an antidepressant medicine, and psychotherapy.

A 2023 study in 104 people with depression concluded that single-dose psilocybin-assisted psychotherapy rapidly reduced symptoms of depression within 8 days, with benefits lasting for 6 weeks.

Research Funded by NCCIH

NCCIH is supporting research to: 

  • Better understand the chemistry of psilocybin to determine the risk for interactions when psilocybin is used along with conventional medicines for psychiatric disorders, migraine headaches, and neuropathic pain, known as selective serotonin reuptake inhibitors (SSRIs).
  • Test the effect of psilocybin on people with chronic low-back pain and depression in regard to their emotions and perceptions of pain.
  • Study the safety and early efficacy of psychedelic-assisted therapy for chronic pain.

More To Consider

  • Don’t use psilocybin to postpone seeing a health care provider about a medical or mental health problem. 
  • Take charge of your health—talk with your health care providers about any complementary health approaches you use. Together, you can make shared, well-informed decisions. 

For More Information

NCCIH Clearinghouse

The NCCIH Clearinghouse provides information on NCCIH and complementary and integrative health approaches, including publications and searches of Federal databases of scientific and medical literature. The Clearinghouse does not provide medical advice, treatment recommendations, or referrals to practitioners. 

Toll-free in the U.S.: 1-888-644-6226 

TTY (for deaf and hard-of-hearing callers): 1-866-464-3615 



Know the Science

NCCIH and the National Institutes of Health (NIH) provide tools to help you understand the basics and terminology of scientific research so you can make well-informed decisions about your health. Know the Science features a variety of materials, including interactive modules, quizzes, and videos, as well as links to informative content from Federal resources designed to help consumers make sense of health information. 

Explaining How Research Works (NIH) 

Know the Science: 9 Questions To Help You Make Sense of Health Research 

Understanding Clinical Studies (NIH) 


A service of the National Library of Medicine, PubMed® contains publication information and (in most cases) brief summaries of articles from scientific and medical journals. For guidance from NCCIH on using PubMed, see How To Find Information About Complementary Health Approaches on PubMed


Key References

Other References

  • Alcohol and Drug Foundation. Psilocybin (magic mushrooms). Alcohol and Drug Foundation website. Accessed at on September 20, 2023. 
  • Heal DJ, Gosden J, Smith SL, et al. Experimental strategies to discover and develop the next generation of psychedelics and entactogens as medicines. Neuropharmacology. 2023;225:109375. 
  • Marks M. The varieties of psychedelic law. Neuropharmacology. 2023;226:109399. 
  • Marks M, Shachar C. Drug scheduling limits access to essential medicines and should be reformed. Nature Medicine. 2023;29(2):294-297.
  • Oregon Health Authority. Oregon psilocybin services. Oregon Health Authority website. Accessed at on April 5, 2023.
  • Rosa WE, Sager Z, Miller M, et al. Top ten tips palliative care clinicians should know about psychedelic-assisted therapy in the context of serious illness. Journal of Palliative Medicine. 2022;25(8)1273-1281.
  • Van Court RC, Wiseman MS, Meyer KW, et al. Diversity, biology, and history of psilocybin-containing fungi: suggestions for research and technological development. Fungal Biology. 2022;126(4):308-319.


NCCIH thanks the following people for their technical expertise and review of this publication: Stephen Ross, M.D., NYU Grossman School of Medicine, NYU Langone Center for Psychedelic Medicine, and Psychedelic Medicine Research Training Program; Charles S. Grob, M.D., UCLA School of Medicine; and D. Craig Hopp, Ph.D., Patrick Still, Ph.D., and David Shurtleff, Ph.D., NCCIH.

This publication is not copyrighted and is in the public domain. Duplication is encouraged.

NCCIH has provided this material for your information. It is not intended to substitute for the medical expertise and advice of your health care provider(s). We encourage you to discuss any decisions about treatment or care with your health care provider. The mention of any product, service, or therapy is not an endorsement by NCCIH.

Last Updated: May 2024