Acute Psychological Distress: Risks and Urgent Help

Urgent help first

If someone may be in danger, is having chest pain, trouble breathing, a seizure, extreme confusion or agitation, or has lost consciousness, call 911 in the US. If someone is thinking about suicide, the 988 Suicide & Crisis Lifeline can be reached in the US by calling or texting 988. For a possible poisoning in the US, Poison Help is 1-800-222-1222 (see poison help by country and poisoning: what to do first). Outside the US, use your local emergency number. This page is education only. It does not tell anyone how to use these substances or how to manage an experience on their own. More detail on warning signs is on when to seek urgent help.

What this page covers

"Acute psychological distress" here means intense fear, panic, confusion, paranoia or feeling out of control during or soon after taking a psychedelic or dissociative substance. People often call this a "bad trip." The sources below describe how common it is, what has happened to people, and what it means for safety. Evidence labels used: established (consistent in reviews or regulator documents), mixed, insufficient evidence, and evidence of harm (documented harm in reports or studies).

What the sources report

The National Institute on Drug Abuse (NIDA) says psychedelics can produce fear, anxiety and confusion, and notes that research on how often these experiences occur is limited, partly because definitions and reporting vary. [1] NIDA also says that using these drugs has been linked to dangerous behavior and injuries, because thought and perception can be impaired. [1]

An online survey of 1,993 people about their single most difficult experience after eating psilocybin mushrooms (self-selected and based on memory, so it cannot give true rates) found:

• 39% rated it among the five most challenging experiences of their lives.
• 11% put themselves or others at risk of physical harm; risk was more likely when the experience was harder and when physical comfort and social support were missing.
• 2.6% acted in a physically aggressive or violent way, and 2.7% received medical help.
• Among those whose experience was more than a year earlier, 7.6% sought treatment for lasting psychological symptoms; three cases seemed linked to lasting psychotic symptoms and three to suicide attempts.
• 84% said they benefited from the experience, and the authors note that risky behavior and lasting distress are extremely rare when psilocybin is given in laboratory studies to screened, prepared and supported people. [2]

A systematic review of 44 articles on supervised treatments with psilocybin, LSD, ayahuasca and MDMA in 598 patients found nausea, headache and anxiety to be the commonly reported short-term adverse events. It found that treatments seemed overall well tolerated, but that adverse events were poorly defined, often not systematically measured and probably underreported. It also reported that psychologically challenging experiences in these studies were sometimes described as therapeutically meaningful. [3] That finding comes from screened participants with trained staff and does not transfer to use outside a clinic. NIDA makes the same point: poor mental health outcomes may be more likely outside clinical use. [1]

Ketamine and esketamine

Ketamine and esketamine are dissociatives, not classic psychedelics. The US label for esketamine (Spravato) says 61% to 84% of treated patients developed dissociative or perceptual changes, and requires monitoring by a health professional for at least 2 hours at each session. [4] NIDA reports that unsupervised ketamine use may carry serious health risks, including respiratory depression. [5] See ketamine and esketamine.

Products with unknown contents

US poison center data on 362 reported exposures to psychoactive mushroom edibles in 2023 to 2024 found that exposure to more than one substance, confusion, and central nervous system depression were each linked to hospital admission and to more serious toxicity. The authors describe these products as unregulated, often with unlisted ingredients and inconsistent formulations. [6] NIDA warns that illicit drugs can be contaminated with colorless, odorless fentanyl. [1]

Who may be at higher risk

Trials exclude people with psychosis or bipolar disorder, and sometimes other mental illnesses, as a precaution. [1] See psychosis vulnerability and mania and bipolar-related concerns. Other medicines can also change the risk; see psychedelic drug interactions and toxicology.

Gaps

Proper evidence not found for how well any bystander or non-clinical response reduces harm. The sources checked (NIDA, PubMed reviews and surveys, the esketamine label) describe harms but do not test responses outside clinics, so this page offers none. After a distressing experience that does not settle, talk with a clinician: talking with a health professional.