The psychotomimetic states inventory (PSI): measuring psychotic-type experiences from ketamine and cannabis.
Oliver J Mason, Celia J M Morgan, Ana Stefanovic, Helen Valerie Curran
Schizophrenia Research August 2008 DOI: 10.1016/j.schres.2008.02.020 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Repeated measures experimental and naturalistic study Peer reviewed |
|---|---|
| Interventions | Ketamine Cannabis |
| Measures | Psychotomimetic States Inventory (PSI) |
| Topics | Cannabis Esketamine Ketamine |
| Key findings | Both ketamine and cannabis produced reliable increases in psychotomimetic state effects across several sub-scales of the Psychotomimetic States Inventory. The authors propose the PSI as a potentially useful measure of the nature and extent of phenomenological effects of psychotropic drugs in schizophrenia-related research. |
Abstract
This study reports a new measure of psychotomimetic states in the context of cannabis and ketamine use. The Psychotomimetic States Inventory (PSI) has sub-scales of Delusory Thinking, Perceptual Distortions, Cognitive Disorganization, Anhedonia, Mania and Paranoia. The PSI was administered in two independent group, repeated measures designs: an experimental study of ketamine and a naturalistic study of cannabis. Both cannabis and ketamine produced reliable increases in ratings of psychotomimetic state effects across several sub-scales. The PSI is a potentially useful measure of the nature and extent of the phenomenological effects of psychotropic drugs in schizophrenia-related research.
Comparable studies
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|---|---|---|---|
| Smoked Cannabis' Psychomotor and Neurocognitive Effects in Occasional and Frequent Smokers Occasional (<2x/week) and frequent (≥4x/week) cannabis smokers | 2015 | Controlled within-subjects study | n = 25 |
| Dissociable effects of cannabis with and without cannabidiol on the human brain’s resting-state functional connectivity Healthy volunteers experienced with cannabis but not regular users | 2019 | Within-subjects experimental design | n = 17 |
| Which biological and self-report measures of cannabis use predict cannabis dependency and acute psychotic-like effects? Young cannabis users | 2018 | Observational study (naturalistic, within-subject counterbalanced design) | n = 410 |
| Cannabis Essential Oil: A Preliminary Study for the Evaluation of the Brain Effects Healthy volunteers | 2018 | Experimental study | n = 5 |
| Coming off cannabis: a cognitive and magnetic resonance imaging study in patients with multiple sclerosis Patients with multiple sclerosis who began using cannabis after disease onset, used it... | 2019 | Quasi-experimental study with odd-even allocation | n = 40 |
Citations in the library
Cited by 49
- The paradoxical psychological effects of lysergic acid diethylamide (LSD) Psychological Medicine February 5, 2016
- Ketamine Has Distinct Electrophysiological and Behavioral Effects in Depressed and Healthy Subjects Molecular Psychiatry February 27, 2018
- Adjunctive Ketamine With Relapse Prevention–Based Psychological Therapy in the Treatment of Alcohol Use Disorder American Journal of Psychiatry January 11, 2022
- Exploratory study of the dose-related safety, tolerability, and efficacy of dimethyltryptamine (DMT) in healthy volunteers and major depressive disorder. Neuropsychopharmacology September 1, 2022
- Dose-related behavioral, subjective, endocrine, and psychophysiological effects of the κ opioid agonist Salvinorin A in humans. Biological Psychiatry November 15, 2012
and 44 more in the library
Cites 4
- Psychological effects of ketamine in healthy volunteers. Phenomenological study. The British Journal of Psychiatry August 1, 2006
- Cannabis-Induced Psychosis-Like Experiences Are Associated with High Schizotypy Psychopathology 2006
- The psychotomimetic effects of intravenous delta-9-tetrahydrocannabinol in healthy individuals: implications for psychosis. Neuropsychopharmacology August 2004
- Effects of cannabis and psychosis vulnerability in daily life: an experience sampling test study Psychological Medicine 2003