Related Experiment Video
Updated: Mar 11, 2026

Brain Morphology of Cannabis Users With or Without Psychosis: A Pilot MRI Study
Published on: August 18, 2020
Are deficits in cognition associated with psychotic-like experiences after cannabis?
Emma Barkus1, Paul Morrison2, Marta Di Forti2
1School of Psychology, University of Wollongong, Wollongong, New South Wales, Australia.
Abstract:
Not all individuals who smoke cannabis report psychotic-like experiences. Given that risk factors for psychotic disorders are multifaceted, precipitating factors to psychotic-like experiences after cannabis are likely to be equally complex. Reduced neurocognitive performance is associated with both psychosis risk and cannabis use. Therefore, it is possible cognitive performance may differentiate those who report psychotic-like experiences after cannabis from those who do not. We determined whether those reporting psychotic/dysphoric experiences after cannabis had reduced neurocognitive performance compared to those reporting primarily euphoric experiences.
Methods:
Participants were recruited on the basis of responses to the cannabis high captured by the Psychosis-Dysphoric and Euphoric experiences subscales from the Cannabis Experiences Questionnaire (CEQ).
Results:
Compared to participants reporting primarily euphoric cannabis experiences (n = 36; 44% male; mean age (SD) = 28 (9) years), those who reported psychotic/dysphoric experiences (n = 40; 45% male; mean age (SD) = 26 (5) years) demonstrated significantly faster responses to a trial and error learning task. In the presence of distracters, those with psychotic/dysphoric experiences after cannabis made more errors on a Continuous Performance Task.
Conclusions:
Those who report psychotic/dysphoric experiences after cannabis have subtle inefficiencies in their cognitive processes. The multiple factors which predict vulnerability to psychotic-like experiences after cannabis require further investigation.
Related Concept Videos
Negative and Cognitive Symptoms of Schizophrenia
Negative Symptoms
Negative symptoms of schizophrenia manifest as deficits in normal emotional and behavioral functioning, profoundly impacting daily life. Individuals with schizophrenia often display a flat affect, characterized by a near-total absence of emotional expression,...
Psychosis: Pathophysiology of Schizophrenia and Other Psychotic Disorders
Researchers have identified genetic factors that increase susceptibility to schizophrenia, underscoring the intricate interplay between genetics and environment in disease development. At the core of schizophrenia's pathophysiology is excessive dopaminergic neurotransmission within...
Positive Symptoms Schizophrenia: Hallucinations and Delusions
Hallucinations
Hallucinations in...
Psychosis and Antipsychotic Drugs: Overview
Positive Symptoms of Schizophrenia: Hallucinations and Delusions
Thought Disorders
Disorganized and unusual thought processes mark thought disorders in schizophrenia. One key feature is disorganized speech, where an individual's conversation includes...
Psychological and Sociocultural Causes of Schizophrenia

