Several studies have shown that individuals with a substance-use disorder (SUD) exhibit abnormalities in EEG coherence. For example, individuals with an alcohol-use disorder (AUD) exhibit increased interhemispheric coherence relative to unaffected individuals24, 25 and patients with long-term abstinent and non-abstinent AUD show significant increases in bilateral, intrahemispheric, and posterior coherence values in the alpha and beta frequency bands26. These findings suggest that increased EEG coherence may serve as an endophenotype for AUD. Similarly, Dafters et al. observed reduced coherence in the posterior brain regions of 3,4-methylenedioxymethamphetamine (MDMA) users27. In terms of behavioral addictions, one study found an association between neural connectivity and compulsive buying behavior using EEG coherence analyses28, which suggests that dysfunctional cortical connectivity may also be associated with addictive behaviors.
