Interhemispheric EEG Coherence as a Candidate Biomarker in Gambling Disorder: Evidence of Frontal Hyperconnectivity and Posterior Disconnectivity

Abstract

Background Gambling Disorder (GD) is a behavioral addiction marked by impaired decision-making and poor impulse control. We investigated whether resting-state interhemispheric quantitative EEG (qEEG) coherence-a measure of functional connectivity between homologous cortical regions-could serve as a biomarker of GD.Methods Twenty-nine male patients with GD and 45 healthy male controls underwent resting-state qEEG recording. Coherence was computed for homologous electrode pairs across delta, theta, alpha, and beta bands. Group differences were analyzed using independent-samples t-tests; associations with disorder duration were assessed via age-controlled partial correlations.Results Consistent with our hypothesis, GD participants exhibited frontal pole hypercoherence (Fp1-Fp2) across delta, theta, and beta bands, which is likely influenced by prefrontal/orbitofrontal generators. In contrast, GD showed hypocoherence in temporal (T3-T4, T5-T6), central (C3-C4), and parietal (P3-P4) regions across these frequencies. Greater disorder duration was associated with lower beta coherence at F3-F4 and Fp1-Fp2, and higher delta coherence at O1-O2.Conclusions These findings reveal a dual pattern of interhemispheric connectivity disruption in GD-hypercoherence at frontal pole sites and hypocoherence in sensorimotor and attentional posterior networks-supporting theoretical models of addiction neurocircuitry. Resting-state qEEG coherence holds promise as a clinically relevant biomarker for GD and may inform the development of neuromodulatory interventions aimed at network rebalancing.