Regional and cannabis-related differences in prefrontal multiscale entropy of resting-state EEG.
William T Creel, Colleen A Brenner, Richard E Hartman
Clinical Neurophysiology Practice 2026 DOI: 10.1016/j.cnp.2026.02.003 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort Peer reviewed |
|---|---|
| Sample size | 57 |
| Population | Adults categorized as non-users, low-frequency users (≤1x/week), and frequent users (≥2x/week) of cannabis |
| Topics | Cannabis |
| Keywords | Electroencephalography Entropy Neurophysiology Prefrontal cortex |
| Key findings | Frequent cannabis users show a significantly flatter prefrontal cortex multiscale entropy slope, indicating reduced neural signal complexity at longer temporal scales. |
Abstract
Entropy analysis of electroencephalographic (EEG) data provides insight into the complexity of neural activity. This study primarily examined whether cannabis use frequency is associated with alterations in multiscale entropy (MSE) in the prefrontal cortex (PFC) and mapped baseline MSE differences across cortical regions. Resting-state EEG was collected from 57 adults: non-users (n = 18), low-frequency users (≤ 1x/week; n = 24), and frequent users (≥ 2x/week; n = 15). MSE values were binned into fine, medium, coarse, and very-coarse scale ranges. Linear mixed-effects models assessed group × scale bin interactions in the PFC and regional differences among lobes, irrespective of cannabis use. Entropy increased with coarser scales in all groups, but the slope was significantly flatter in frequent users. From the medium bin onward, their PFC scale-entropy slope was ∼ 0.12 bits lower than in non-users, widening to ∼ 0.16 bits at very-coarse scales (FDR-corrected q < 0.012). Across all participants, the PFC exhibited lower MSE than parietal, occipital, and temporal lobes, with regional gaps expanding at coarser scales. The PFC exhibits intrinsically reduced signal complexity compared with other cortical regions, with further attenuation in frequent cannabis users. MSE captures regional cortical dynamics in resting EEG and detects cannabis-related reductions in prefrontal signal complexity at longer temporal scales.
Comparable studies
Other observational and cohort studies on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| High-potency cannabis and the risk of psychosis People with first episode of psychosis and healthy controls from the local population | 2009 | Case-control study | n = 454 |
| Ayahuasca-Assisted Therapy for Addiction: Results from a Preliminary Observational Study in Canada Rural aboriginal population | 2013 | Observational study | |
| Impaired cognitive performance in drug free users of recreational ecstasy (MDMA) Otherwise healthy young people | 2000 | Observational | |
| Continued cannabis use and risk of incidence and persistence of psychotic symptoms: 10 year follow-up cohort study Individuals from the general population in Germany aged 14-24 at baseline | 2011 | Observational cohort | n = 1,923 |
| Cannabis-induced psychosis and subsequent schizophrenia-spectrum disorders: follow-up study of 535 incident cases Patients treated for cannabis-induced psychotic symptoms in Denmark between 1994 and... | 2005 | Observational cohort | n = 535 |