Other · 2025
A shorter, updated questionnaire for measuring psychedelic experiences: the 3D-ASCr
- Original title
- The 3D-ASCr scale: A revalidation of the core dimensions of the Altered States of Consciousness Rating Scale 5D(11)-ASC for psychedelic research.
- Authors
- Stocker K, Hartmann M, Schmid Y, et al.
- Journal
- Journal of psychopharmacology (Oxford, England), 2025
- Molecules
- Psilocybin, LSD, DMT, Mescaline
- Conditions
- Healthy volunteers
- Participants
- 398
- Evidence grade
- Low
- Source
- Read the original paper
The question
Can the widely used questionnaire for measuring altered states of consciousness be reorganized into a clearer, shorter three-part structure that still fits the data well?
What they did
Researchers pooled 901 completed Altered States of Consciousness questionnaires from 398 healthy participants who had taken part in 16 randomized, mostly placebo-controlled studies of LSD, psilocybin, mescaline or DMT. They split the data into two halves: one to look for underlying patterns, and one to test whether those patterns held up. They compared the older 66-item three-dimension version of the scale with the newer 42-item version that has 11 subscales.
What they found
Ten of the 11 subscales grouped neatly into three broader dimensions: positive effects, distressing effects and perceptual effects. This three-part structure mirrored the original three-dimension scale but fit the data better while using fewer items. The Anxiety subscale could not be folded in, because scores on it were consistently very low in this sample of healthy volunteers. The authors kept Anxiety in the proposed scale anyway, given its clinical importance, either within the distressing-effects dimension or on its own.
The fine print
The data come only from healthy volunteers in controlled research settings, so the results may not transfer to patients being treated for a mental health condition, where anxiety and distress are likely more common. The floor effect on the Anxiety subscale means that part of the scale was not properly tested here. This is a measurement study: it says nothing about whether psychedelics help anyone. This summary is based on the abstract alone.
What it means
Researchers now have a shorter, statistically tidier way to summarize what people experience during a psychedelic session, which should make results easier to compare across studies.
Evidence grade: Low. This is a statistical re-analysis of questionnaire data pooled from earlier trials, not a new trial testing a treatment outcome.
This summary is based on the study’s published abstract.