Altered functional connectivity and oscillatory dynamics in polysubstance and cannabis only users during visuospatial processing.
Lucas Weyrich, Yasra Arif, Mikki Schantell, Hallie J Johnson, Madelyn P Willett, Hannah J Okelberry, Tony W Wilson
Psychopharmacology April 2023 DOI: 10.1007/s00213-023-06318-6 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cross-sectional study Peer reviewed |
|---|---|
| Sample size | 56 |
| Population | Adults: 18 polysubstance users (cannabis plus at least one other illicit substance), 19 cannabis-only users, and 19 nonusers |
| Topics | Addiction Cannabis |
| Keywords | Beta Drug Gamma Meg Magnetoencephalography Oscillations Theta |
| Key findings | Cannabis-only users showed weaker occipital theta than nonusers, and both cannabis-only and polysubstance users showed reduced spontaneous occipital gamma during the pre-stimulus baseline relative to nonusers. Polysubstance users had sharply reduced beta connectivity between occipital and prefrontal, and occipital and left temporal, cortices. The authors argue that cannabis use should be considered in a polysubstance context and that future work should distinguish polysubstance combinations and use causal designs. |
Abstract
Cannabis use is often associated with the use of other psychoactive substances, which is subsequently linked to an increased risk for addiction. While there is a growing body of neuroimaging literature investigating the cognitive effect of long-term cannabis use, very little is known about the potential additive effects of cannabis polysubstance use. Fifty-six adults composed of 18 polysubstance users (i.e., cannabis plus at least one other illicit substance), 19 cannabis-only users, and 19 nonusers completed a visuospatial attention task while undergoing magnetoencephalography. A data-driven approach was used to identify oscillatory neural responses, which were imaged using a beamforming approach. The resulting cortical regions were probed for group differences and used as seeds for whole-brain connectivity analysis. Participants exhibited robust theta, alpha, beta, and gamma responses during visuospatial processing. Statistical analyses indicated that the cannabis-only group had weaker occipital theta relative to the nonusers, and that both polysubstance and cannabis-only users had reduced spontaneous gamma in the occipital cortices during the pre-stimulus baseline period relative to nonusers. Finally, functional connectivity analyses revealed that polysubstance users had sharply reduced beta connectivity between occipital and prefrontal, as well as occipital and left temporal cortices. Cannabis use should be considered in a polysubstance context, as our correlational design suggests differences in functional connectivity among those who reported cannabis-only versus polysubstance use in occipital to prefrontal pathways critical to visuospatial processing and attention function. Future work should distinguish the effect of different polysubstance combinations and use more causal designs.
Comparable studies
Other cross-sectional and survey studies on cannabis for addiction, most cited first.
Citations in the library
Cited by 6
- Cognitive Outcomes among Cannabis Users with and without a History of Polysubstance Use Journal of Cognitive Enhancement September 14, 2026
- EEG-based network dynamics in cannabis and polydrug use: a directed transfer function approach. Psychopharmacology October 20, 2025
- Chronic cannabis use differentially modulates neural oscillations serving the manipulate versus maintain components of working memory processing. Neurobiology of Disease February 1, 2025
- Altered Functional Connectivity Dynamics Serving Cognitive Flexibility in Regular Cannabis Users. Addiction Biology February 1, 2025
- Regular cannabis use modulates gamma activity in brain regions serving motor control. Journal of Psychopharmacology November 1, 2024
and 1 more in the library
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and 9 more in the library