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Testing the role of the posterior cingulate cortex in processing salient stimuli in cannabis users: an rTMS study

Shikha Prashad, Elizabeth S. Dedrick, Wing Ting To, Sven Vanneste, Francesca Mapua Filbey

European Journal of Neuroscience October 6, 2018 DOI: 10.1111/ejn.14194 (opens in new tab)

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Study at a glance

AI-extracted from the abstract
Characteristics Double-blind, placebo-controlled study Peer reviewed
Sample size 20
Population 10 adult cannabis users and 10 age- and sex-matched non-using controls
Intervention Repetitive transcranial magnetic stimulation (rTMS)
Dose 10 Hz (high frequency) and 1 Hz (low frequency)
Measures P3 amplitude, P3 latency, N2 latency, P2 latency
Topics Cannabis
Citations 26
Key points At baseline, cannabis users showed increased P3 amplitude and faster P3, N2, and P2 latencies in response to self-relevant stimuli compared with controls, and these differences normalized after rTMS. The authors suggest this reflects heightened salience to external self-relevant stimuli in cannabis users that was modulated by rTMS, and propose PCC dysfunction as a potential target for cannabis use disorder intervention.

Abstract

The posterior cingulate cortex (PCC) and precuneus are hubs in the default mode network and play a role in processing external salient stimuli. Accordingly, activation in these regions has been associated with response to salient stimuli using drug cue-reactivity paradigms in substance using populations. These studies suggest that the PCC and precuneus may underlie deficits in processing salient stimuli that contribute toward the development of substance use disorders. The goal of this study was to directly test this hypothesis using repetitive transcranial magnetic stimulation (rTMS). Using a double-blind, placebo-controlled design, we used rTMS to target the PCC and precuneus with a double-cone coil at 10 Hz (high frequency) and 1 Hz (low frequency) in 10 adult cannabis users and 10 age- and sex-matched non-using controls. Electroencephalography data were collected before and after rTMS during a modified oddball paradigm with neutral, oddball, self-relevant, and cannabis-related stimuli. Cannabis users exhibited increased amplitude in P3 and faster latencies in the P3, N2, and P2 components in response to self-relevant stimuli compared to controls during baseline that normalized after rTMS. These results suggest that cannabis users exhibited heightened salience to external self-relevant stimuli that were modulated after rTMS. PCC dysfunction in cannabis users may be related to abnormalities in processing salient stimuli, such those during cue-reactivity, and provides a potential target for cannabis use disorder intervention.

Comparable studies

Other randomized controlled trials on cannabis, most cited first.

Study Year Design Participants
Cannabidiol inhibits THC-elicited paranoid symptoms and hippocampal-dependent memory impairment Healthy participants 2012 Randomized controlled trial n = 48
Distinct Effects of Δ9-Tetrahydrocannabinol and Cannabidiol on Neural Activation During Emotional Processing Healthy, English-native, right-handed men who had used cannabis 15 times or less in... 2009 Double-blind, randomized, placebo-controlled crossover trial n = 15
Acute Effects of a Single, Oral dose of d9-tetrahydrocannabinol (THC) and Cannabidiol (CBD) Administration in Healthy Volunteers Healthy male subjects 2012 Randomized controlled trial n = 16
Modulation of Mediotemporal and Ventrostriatal Function in Humans by Δ9-Tetrahydrocannabinol Healthy, native English-speaking, right-handed men of white race/ethnicity who had used... 2009 Randomized controlled trial n = 15
Cannabidiol (CBD) content in vaporized cannabis does not prevent tetrahydrocannabinol (THC)-induced impairment of driving and cognition Healthy volunteers with a history of light cannabis use 2019 Randomized, double-blind, within-subjects crossover n = 14

Citations in the library

Cites 5

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