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Brain Morphology of Cannabis Users With or Without Psychosis: A Pilot MRI Study
Published on: August 18, 2020
Disrupted 'reflection' impulsivity in cannabis users but not current or former ecstasy users.
L Clark1, J P Roiser, T W Robbins
1Behavioural and Clinical Neuroscience Institute, Department of Experimental Psychology, School of Clinical Medicine, University of Cambridge, and Addenbrooke's Hospital, Cambridge, UK. lc260@cam.ac.uk
Journal of Psychopharmacology (Oxford, England)
|June 3, 2008
Summary
Ecstasy users did not show increased impulsivity on a new cognitive task, contrary to expectations. However, cannabis users exhibited reduced information sampling, suggesting a broader cognitive style change in substance users.
Area of Science:
- Neuroscience
- Psychology
- Cognitive Science
Background:
- Serotonin's role in impulsivity is well-documented, prompting research into ecstasy users due to suspected serotonergic dysfunction.
- Existing research on impulsivity in ecstasy users yields inconsistent findings, necessitating further investigation.
Purpose of the Study:
- To measure 'reflection' impulsivity using a novel Information Sampling Test in current ecstasy users, past ecstasy users, current cannabis users, and drug-naïve controls.
- To investigate the complex relationship between serotonin function, ecstasy use, and impulsivity.
Main Methods:
- Utilized a recently developed Information Sampling Test to assess 'reflection' impulsivity.
- Compared cognitive performance across four groups: 46 current ecstasy users, 14 past ecstasy users, 15 current cannabis users, and 19 drug-naïve controls.
- Administered the Eysenck Impulsiveness-Venturesomeness-Empathy questionnaire.
Main Results:
- Current and past ecstasy users did not differ from drug-naïve controls on the Information Sampling Test, despite reporting higher impulsivity scores on a self-report questionnaire.
- Cannabis users sampled significantly less information and tolerated lower certainty in decision-making compared to drug-naïve controls.
- These findings suggest reduced reflection may be a common cognitive style in regular users of various substances, but the ecstasy-serotonin-impulsivity link is complex.
Conclusions:
- The study challenges the direct link between ecstasy use and measurable 'reflection' impulsivity, suggesting a more complex interaction involving serotonin.
- Reduced information sampling observed in cannabis users aligns with findings in other substance-dependent individuals, indicating a potential shared cognitive style.
- Further research is needed to elucidate the intricate relationship between serotonergic function, ecstasy consumption, and impulsive behaviors.
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