CEQ

The Challenging Experience Questionnaire (CEQ) is a 26-item self-report measure developed by Frederick Barrett and colleagues at Johns Hopkins University to assess the occurrence and intensity of difficult or challenging experiences during psychedelic sessions. It measures seven domains: grief, fear, death, insanity, isolation, physical distress, and paranoia. Each item is rated on a 0–5 scale (0 = none, 5 = extreme), with scores expressed as a percentage of maximum. The CEQ is an important safety and characterization measure in psychedelic clinical trials, as challenging experiences (commonly called ‘bad trips’) can occur even in controlled settings and may impact therapeutic outcomes. Interestingly, research has shown that moderate challenging experiences, when well-supported, can sometimes contribute positively to therapeutic outcomes. The CEQ helps researchers and clinicians quantify and contextualize these experiences.