People in Canada who receive emergency or hospital care after using hallucinogens are six times more likely to require treatment for mania within the following three years, according to a study published on December 2 in PLOS Medicine. The research was led by Daniel Myran from North York General Hospital and his colleagues.
The study looked at data collected between January 2008 and December 2022. It compared individuals who received acute care for hallucinogen use—such as ketamine, LSD, or psilocybin—to those hospitalized for other reasons and to the general population. The goal was to determine whether there is an increased risk of future emergency visits or hospitalization for mania, or a new diagnosis of bipolar disorder (BD), among people treated for hallucinogen use.
Among 7,285 patients who had emergency or hospital care related to hallucinogen use, the risk of later treatment for mania was six times higher than among 78,201 patients hospitalized for other causes. These patients were also four times more likely to be diagnosed with BD over the next three years compared to those hospitalized for non-hallucinogen reasons. The study found that this risk level is similar to what has been observed with cannabis-related acute care cases. Most people receiving urgent care for hallucinogen use had previous substance use visits, and nearly half had prior mental health care visits.
The authors caution that their findings mainly apply to people whose hallucinogen use resulted in the need for urgent medical attention. "The findings may be due to ED or hospital care involving hallucinogen use occurring in individuals at greater risk for mania or BD rather than a direct risk of hallucinogens," they note.
Daniel Myran said, "Our study showed a strong association between hallucinogen use that requires care in the emergency room or hospital and future risk of mania and bipolar disorder."
He added, "There has been a large increase in interest in the use of hallucinogens, often paired with therapy, to treat some mental health disorders. The current study helps highlight that hallucinogen use outside of trial settings may have important risks for a subset of people who use them."
Coauthor Marco Solmi stated, "Our results fill an important gap around the complexity of therapeutic versus safety profile of hallucinogen use. Future projects will need to identify predictors of beneficial versus harmful outcomes at the individual level."
