Salience attribution and its relationship to cannabis-induced psychotic symptoms.
Michael Bloomfield, E Mouchlianitis, C J A Morgan, Tom P. Freeman, Hv Curran, Jonathan P. Roiser, Oliver Howes
Psychological Medicine December 2016 DOI: 10.1017/s0033291716002051 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Case-control study Longitudinal Peer reviewed |
|---|---|
| Sample size | 34 |
| Population | 17 cannabis users and 17 age- and sex-matched non-user controls; dopamine synthesis capacity measured in 10 users and six controls |
| Measures | Salience Attribution Test, Psychotomimetic States Inventory, 3,4-dihydroxy-6-[18F]fluoro-l-phenylalanine positron emission tomography (Ki cer) |
| Topics | Addiction Cannabis |
| Keywords | Dopamine Psychosis Salience |
| Key findings | Cannabis users as a group did not differ from controls in aberrant salience, but within users greater cannabis-induced psychotic symptom severity was associated with higher explicit aberrant salience (r = 0.61), and cannabis dependence or abuse was associated with higher implicit aberrant salience. The authors argue the pattern is consistent with altered salience processing linking cannabis use to psychosis, though causality remains undetermined. |
Abstract
Cannabis is a widely used drug associated with increased risk for psychosis. The dopamine hypothesis of psychosis postulates that altered salience processing leads to psychosis. We therefore tested the hypothesis that cannabis users exhibit aberrant salience and explored the relationship between aberrant salience and dopamine synthesis capacity. We tested 17 cannabis users and 17 age- and sex-matched non-user controls using the Salience Attribution Test, a probabilistic reward-learning task. Within users, cannabis-induced psychotic symptoms were measured with the Psychotomimetic States Inventory. Dopamine synthesis capacity, indexed as the influx rate constant K i cer , was measured in 10 users and six controls with 3,4-dihydroxy-6-[18F]fluoro-l-phenylalanine positron emission tomography. There was no significant difference in aberrant salience between the groups [F 1,32 = 1.12, p = 0.30 (implicit); F 1,32 = 1.09, p = 0.30 (explicit)]. Within users there was a significant positive relationship between cannabis-induced psychotic symptom severity and explicit aberrant salience scores (r = 0.61, p = 0.04) and there was a significant association between cannabis dependency/abuse status and high implicit aberrant salience scores (F 1,15 = 5.8, p = 0.03). Within controls, implicit aberrant salience was inversely correlated with whole striatal dopamine synthesis capacity (r = -0.91, p = 0.01), whereas this relationship was non-significant within users (difference between correlations: Z = -2.05, p = 0.04). Aberrant salience is positively associated with cannabis-induced psychotic symptom severity, but is not seen in cannabis users overall. This is consistent with the hypothesis that the link between cannabis use and psychosis involves alterations in salience processing. Longitudinal studies are needed to determine whether these cognitive abnormalities are pre-existing or caused by long-term cannabis use.
Comparable studies
Other observational and cohort studies on cannabis for addiction, most cited first.
Citations in the library
Cited by 9
- Acute effects of different types of cannabis on young adult and adolescent resting-state brain networks Neuropsychopharmacology May 28, 2024
- Does cannabis use predict psychometric schizotypy via aberrant salience? Schizophrenia Research April 6, 2020
- Cannabis Use, Schizotypy and Kamin Blocking Performance Frontiers in Psychiatry November 23, 2021
- Alexithymia and psychopathological dimensions in First-Episode Psychosis: Comparative patterns in natural cannabis versus synthetic cannabinoid users Journal of Psychiatric Research June 19, 2025
- Self-disturbance in first-episode psychosis: Theoretical framework and potential cannabis interactions - a systematic review. Frontiers in Psychiatry 2025
and 4 more in the library
Cites 12
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- Traditional marijuana, high‐potency cannabis and synthetic cannabinoids: increasing risk for psychosis World Psychiatry September 22, 2016
- Cannabis use before age 15 and subsequent executive functioning The British Journal of Psychiatry May 31, 2011
- How cannabis causes paranoia: using the intravenous administration of ∆9-tetrahydrocannabinol (THC) to identify key cognitive mechanisms leading to paranoia. Schizophrenia Bulletin March 2015
- Dopamine release in chronic cannabis users: a [11c]raclopride positron emission tomography study. Biological Psychiatry April 15, 2012
and 7 more in the library