Cannabidiol Modulates Right Fronto-Parietal Connectivity in Autistic Children: A Secondary EEG Analysis from a Randomised Placebo-Controlled Crossover Trial

Autistic children often show altered brain network connectivity, including circuitry implicated in social cognition. Cannabidiol (CBD) has emerged as a potential therapy for autism, but its neural mechanisms remain under-researched. Here, we report an analysis of resting-state electroencephalography (EEG) data collected as part of a double-blind, placebo-controlled crossover trial, to explore whether 12 weeks of oral CBD oil treatment could modulate functional connectivity in autistic children. Twenty-nine autistic children (5-12 years) completed two 12-week intervention periods (CBD and placebo, randomised) separated by an 8-week washout. Before and after each intervention period, five minutes of eyes-open resting-state EEG data were obtained from a subset of 19 participants (8 female). Functional connectivity was calculated across 16 electrode-pairs in the alpha, beta, theta, and gamma bands. Paired t-tests comparing post- versus pre-intervention connectivity values were Benjamini-Hochberg false discovery rate (FDR)-corrected within each band (pFDR < .05). Beta-band connectivity between the right frontal and right inferior-parietal electrodes increased following CBD (p < .001, pFDR = .016) and alpha connectivity showed an increase that did not remain following FDR correction (p = .036, pFDR = .071). No significant connectivity differences were observed following placebo for any frequency band (pFDR > .60). These findings provide preliminary evidence that CBD might enhance connectivity within social cognitive brain networks in autism but will require replication in larger samples.