Prevalence and associations of challenging, difficult or distressing experiences using classic psychedelics

Approximately one in twenty (4.6 %) reported severely impaired ability to function and roughly one in ten (8.9 %) reported impairment that lasted longer than one day.

This study provides insight into the prevalence and associations of challenging, difficult, or distressing experiences using classic psychedelics. The findings broadly correspond with findings from previous studies and can be used to inform both ongoing harm reduction efforts and future experimental research designs.

https://www.sciencedirect.com/science/article/pii/S0165032723000915#s0035