Identifying EEG markers related to acute cannabis consumption: A systematic review.
Neuroscience and biobehavioral reviews May 1, 2025 C Schiemer, M J Summers, K B Stefanidis 2 citations
Acute cannabis administration alters brain electrical activity measured by EEG, particularly reducing the amplitude of the P3 event-related potential and affecting theta frequency band power (4-7 Hz) in a dose-dependent manner. A systematic review of 16 studies found that P3 amplitude decreases consistently across various THC doses, with small-to-moderate effect sizes, suggesting it may serve as a marker of recent cannabis consumption. Oscillatory theta power also changes after cannabis use, with some evidence of dose-dependent effects. However, great heterogeneity in participant characteristics and reported data limits firm conclusions, and effects in highly tolerant users, such as medicinal cannabis patients, require further study.