A new 70-item questionnaire to measure the subjective effects of ibogaine

The question

Can researchers build a reliable questionnaire that captures the unusual, dream-like mental effects people report during ibogaine treatment?

What they did

Ibogaine is a substance from the root bark of the iboga shrub, used traditionally in Bwiti healing rituals and studied for opioid dependence. Existing questionnaires for psychedelic experiences do not capture its distinctive dream-like effects, so the researchers drafted a 144-item questionnaire based on an earlier interview study of 20 people that identified eight areas of experience. Within 48 hours of treatment, 499 people at two clinical settings completed the draft on a mobile device: 381 receiving treatment for neuropsychiatric conditions and 118 for substance use disorders. Statistical methods were then used to cut the item list down and test how well the remaining questions grouped together.

What they found

The final scale had 70 items grouped into seven areas: narrative and symbolic visions; visual changes; discomfort and challenge; cosmic or archetypal visions; introspection and personal transformation; heightened bodily sensations and physical activation; and dissociation (feeling detached from oneself or one’s surroundings). Together these seven areas accounted for 53.9% of the variation in responses. Statistical fit measures were strong (CFI = .991; GFI = .983; RMSR = .041; WRMR = .038), and internal consistency was high overall (Cronbach’s alpha = .948; McDonald’s omega = .946), with subscale omega values ranging from .65 to .91. Two subscales showed small differences by gender.

The fine print

This study only tested whether the questionnaire holds together statistically; it did not test whether any experience domain predicts clinical improvement, and it reports no treatment outcomes, safety data or follow-up. Participants were people already undergoing ibogaine treatment at two clinical sites, so the sample is selected and may not represent other groups or cultures; the authors themselves call for replication in independent, culturally diverse cohorts. All responses were self-reported soon after treatment. This summary is based on the abstract alone.

What it means

Researchers now have a structured tool for describing what people experience during ibogaine treatment, which could make future studies easier to compare. It says nothing yet about whether ibogaine helps or is safe.

Evidence grade: Low. This is a questionnaire-development study in people already receiving treatment, with no control group, no randomization and self-reported outcomes.

This summary is based on the study’s published abstract.