The Psychotomimetic States Inventory (PSI): Measuring psychotic-type experiences from ketamine and cannabis

  title={The Psychotomimetic States Inventory (PSI): Measuring psychotic-type experiences from ketamine and cannabis},
  author={Oliver Mason and Celia J. A. Morgan and Anja N D Stefanovic and H Valerie Curran},
  journal={Schizophrenia Research},
The Psychotomimetic Nature of Dreams: An Experimental Study
Overall, participants reported more quasipsychotic characteristics during dreams (in both conditions) than when awake, and subjective changes to cognition and affect are consistent with alterations in prefrontal cortical activity during REM sleep that mirror those of schizophrenia.
Acute cannabis use causes increased psychotomimetic experiences in individuals prone to psychosis
It is suggested that an individual's response to acute cannabis and their psychosis-proneness scores are related and both may be markers of vulnerability to the harmful effects of this drug.
Pharmacological modelling of dissociation and psychosis: an evaluation of the Clinician Administered Dissociative States Scale and Psychotomimetic States Inventory during nitrous oxide ('laughing gas')-induced anomalous states.
The CADSS and PSI tap largely non-overlapping experiences under N2O and it is proposed the use of both measures to comprehensively assess anomalous subjective states produced by dissociative NMDAR antagonists.
Inducing Psychotic-like Experiences without Drugs using the Witches’ Cradle
Various means of inducing unusual or anomalous experiences sharing similarities with psychosis have been proposed. In the present study, an ‘altered states of consciousness induction device’ (ASCID)
The paradoxical psychological effects of lysergic acid diethylamide (LSD)
The present findings reinforce the view that psychedelics elicit psychosis-like symptoms acutely yet improve psychological wellbeing in the mid to long term, and are proposed that acute alterations in mood are secondary to a more fundamental modulation in the quality of cognition.
Cannabis and Hallucinations: Studies in Human Subjects
This chapter examines the relationship between cannabis, psychosis and hallucinations, and describes the small number of studies that have directly examined the effects of cannabis and Δ-9-THC on sensory cortices.
The Psychotomimetic Effects of Short-Term Sensory Deprivation
  • O. Mason, F. Brady
  • Psychology, Medicine
    The Journal of nervous and mental disease
  • 2009
This study explored whether perceptual disturbances could be elicited by a brief period of complete isolation from sound and vision in both highly hallucination prone and nonhallucination prone groups.
Acute effects of cannabis on speech illusions and psychotic-like symptoms: two studies testing the moderating effects of cannabidiol and adolescence
Inhalation of cannabis reliably increases psychotic-like symptoms in healthy cannabis users and may increase the incidence of speech illusion, and adolescents may be less vulnerable to acute psychotic- like effects of cannabis than adults.


Psychological effects of ketamine in healthy volunteers
Ketamine does not reproduce the full picture of schizophrenia, but Phenomena resembling negative symptoms are seen, but the distinction of these from the drug's sedative effects requires further elucidation.
Schizophrenia, ketamine and cannabis: evidence of overlapping memory deficits
Cannabis-Induced Psychosis-Like Experiences Are Associated with High Schizotypy
High scoring schizotypes who use cannabis are more likely to experience psychosis-like phenomena at the time of use, and unpleasant after-effects associated with cannabis use, consistent with the hypothesis that cannabis use is a risk factor for full psychosis.
Effects of cannabis and psychosis vulnerability in daily life: an experience sampling test study
Cannabis use interacts with psychosis vulnerability in their effects on experience of psychosis in daily life and there is no evidence that use of cannabis is increased following occurrence of psychotic experiences as would be expected by the self-medication model.
The Psychotomimetic Effects of Intravenous Delta-9-Tetrahydrocannabinol in Healthy Individuals: Implications for Psychosis
It is indicated that Δ-9-THC produces a broad range of transient symptoms, behaviors, and cognitive deficits in healthy individuals that resemble some aspects of endogenous psychoses and warrant further study of whether brain cannabinoid receptor function contributes to the pathophysiology of psychotic disorders.
Acute and chronic effects of ketamine upon human memory: a review
This article reviews the existing literature on the effects of acute ketamine on the memory of healthy volunteers and of repeated doses of ketamine in recreational users and suggests that ketamine may differ from other classic amnestic drugs in impairing aspects of semantic memory.
PCP: from pharmacology to modelling schizophrenia.
Prospective cohort study of cannabis use, predisposition for psychosis, and psychotic symptoms in young people
Cannabis use moderately increases the risk of psychotic symptoms in young people but has a much stronger effect in those with evidence of predisposition for psychosis.
Cannabinoids and psychosis.
  • D. D’Souza
  • Psychology, Medicine
    International review of neurobiology
  • 2007