Validation of the Psychological Insight Scale: A new scale to assess psychological insight following a psychedelic experience

This survey study (n=279) developed and validated a new scale to measure participants psychological insight after a psychedelic experience: the Psychological Insight Scale (PIS). It was found the PIS is complementary to current measures used in psychedelic studies while insight, as measured by the PIS, was found to mediate the long-term psychological outcomes after a psychedelic experience.


“Introduction: As their name suggests, ‘psychedelic’ (mind-revealing) compounds are thought to catalyse processes of psychological insight; however, few satisfactory scales exist to sample this. This study sought to develop a new scale to measure psychological insight after a psychedelic experience: the Psychological Insight Scale (PIS).

Methods: The PIS is a six- to a seven-item questionnaire that enquires about psychological insight after a psychedelic experience (PIS-6) and accompanying behavioural changes (PIS item 7). In total, 886 participants took part in a study in which the PIS and other questionnaires were completed in a prospective fashion in relation to a planned psychedelic experience. For validation purposes, data from 279 participants were analysed from a non-specific ‘global psychedelic survey’ study.

Results: Principal components analysis of PIS scores revealed a principal component explaining 73.57% of the variance, which displayed high internal consistency at multiple time points throughout the study (average Cronbach’s α = 0.94). Criterion validity was confirmed using the global psychedelic survey study, and convergent validity was confirmed via the Therapeutic-Realizations Scale. Furthermore, PIS scores significantly mediated the relationship between emotional breakthrough and long-term well-being.

Conclusion: The PIS is complementary to current subjective measures used in psychedelic studies, most of which are completed in relation to the acute experience. Insight – as measured by the PIS – was found to be a key mediator of long-term psychological outcomes following a psychedelic experience. Future research may investigate how insight varies throughout a psychedelic process, its underlying neurobiology and how it impacts behaviour and mental health.”

Authors: Joseph M. Peill, Katie E. Trinci, Hannes Kettner, Lea J. Mertens, Leor Roseman, Christopher Timmermann, Fernando E. Rosas, Taylor Lyons & Robin L. Carhart-Harris

Study details

Topics studied

Study characteristics

276 Humans


Authors associated with this publication with profiles on Blossom

Robin Carhart-Harris
Dr. Robin Carhart-Harris is the Founding Director of the Neuroscape Psychedelics Division at UCSF. Previously he led the Psychedelic group at Imperial College London.

Chris Timmermann
Chris Timmerman is a postdoc at Imperial College London. His research is mostly focussed on DMT.

Leor Roseman
Leor Roseman is a researcher at the Centre for Psychedelic Research, Imperial College London. His work focussed on psilocybin for depression, but is now related to peace-building through psychedelics.


Institutes associated with this publication

Imperial College London
The Centre for Psychedelic Research studies the action (in the brain) and clinical use of psychedelics, with a focus on depression.