Acute Anxiety and Distress During Experiences

If you or someone else needs help now

• Immediate danger, trouble breathing, chest pain, seizure, unresponsive, or risk of harm to self or others: call 911 (US).
• Thoughts of suicide or a mental-health crisis (US): call 988, the Suicide & Crisis Lifeline.
• Possible poisoning, including a mushroom or plant that may have been misidentified (US): call Poison Help at 1-800-222-1222. For other countries and first steps, see poison help by country and poisoning: what to do first.

This page describes what research reports. It does not tell anyone how to take, manage or recover from a substance, and it does not replace emergency or medical care. See also when to seek urgent help.

What "distress" means here

People sometimes use "bad trip" for an experience marked by intense fear, panic, paranoia or confusion. NIDA says some people who take psilocybin have extreme fear, anxiety, panic or paranoia during the hallucinogenic effects. [1] In research papers this is called a challenging experience or an acute adverse reaction. NIDA also notes that psychedelic or dissociative drugs may produce adverse or debilitating psychological effects such as fear or anxiety. [2]

Evidence labels used here: established (repeatedly reported in controlled research), insufficient evidence, evidence of harm and approved medicine (regulator and indication named).

What controlled research reports

• Healthy volunteers in supervised studies. Pooled data from eight placebo-controlled studies (110 healthy people) found that acute reactions marked by strong dysphoria, anxiety or panic occurred only at the two highest amounts tested, in a relatively small share of people. All were managed with interpersonal support and needed no medication. Follow-up showed no persisting perception disorders, prolonged psychosis or other long-term impairment in any of the volunteers. [3] Label: established for screened, prepared volunteers in research settings, which is not a description of everyday use.
• LSD. In 16 healthy volunteers, the highest LSD amount tested produced significant anxiety and more ego dissolution than the next one down. [4]
• Treatment-resistant depression. Among 20 patients, a scale for "dread of ego dissolution" was related to later depression score changes, as was a scale for oceanic boundlessness. [5]
• Clinical trial adverse events. In a phase 2 trial in treatment-resistant depression, 77% of participants had adverse events including headache, nausea and dizziness, and suicidal ideation, behavior or self-injury occurred in all dose groups. [6]
• Esketamine label. Anxiety was among the most common adverse reactions in label trials, and the FDA requires monitoring for at least 2 hours after each dose. [7] Label: approved medicine (FDA; treatment-resistant depression and depressive symptoms in major depressive disorder with acute suicidal ideation or behavior).

What research says about the risks of distress

• Research guidelines say the most likely risk of a hallucinogen session is overwhelming distress, which could lead to dangerous behavior such as leaving the study site. Less common are prolonged psychoses triggered by hallucinogens. [8]
• The guidelines list safeguards used in research: excluding volunteers with a personal or family history of psychotic or other severe psychiatric disorders, trust-building and careful preparation beforehand, a safe physical environment, and support from at least two monitors during the session. [8] These describe how studies lower risk. They are not a plan for unsupervised use, and a research setting cannot be recreated at home.
• NIDA links psychedelic and dissociative drugs with dangerous behavior and injuries, especially if no other person is present who can respond to an emergency. [2]

What a survey of difficult experiences found

In an online survey of 1,993 people (mean age 30, 78% male) about their single worst "bad trip" after psilocybin mushrooms: [9]

• 39% rated it among the five most challenging experiences of their lives.
• 11% put themselves or others at risk of physical harm, 2.6% behaved in a physically aggressive or violent way, and 2.7% received medical help.
• Of those whose experience was over a year earlier, 7.6% sought treatment for enduring psychological symptoms. The authors report three cases that appeared linked to onset of enduring psychotic symptoms and three to attempted suicide.
• 84% said they benefited from the experience despite the difficulty.

The authors say the risk of risky behavior or lasting distress is extremely low in laboratory studies of screened, prepared and supported participants. [9] This survey was self-selected and retrospective, so it cannot give true rates for the general public. Label: insufficient evidence for rates, but evidence of harm that serious events do occur.

Who is at higher risk

Research guidelines treat a history of psychosis as an exclusion. [8] For esketamine, the label says patients with psychosis should be carefully assessed. [7] Read more in psychosis vulnerability and acute psychological distress: risks and urgent help.