EEG phenotype in alcoholism: increased coherence in the depressive subtype

Area of Science:

• Neuroscience
• Psychiatry
• Genetics

Background:

• Electroencephalography (EEG) power and coherence may serve as trait markers for alcoholism, offering insights into vulnerability mechanisms.
• It remains unclear if observed EEG differences are due to alcohol's toxic or withdrawal effects.

Purpose of the Study:

• To investigate EEG power and coherence in non-abstinent alcoholics, long-term abstinent alcoholics, and controls.
• To determine if EEG changes are state-dependent (related to recent alcohol use) or trait-dependent (related to predisposition).

Main Methods:

• Analyzed EEG data from 10 non-abstinent alcoholics, 16 long-term abstinent alcoholics (mean abstinence 7.7 years), and 25 controls.
• Assessed anxiety and depression levels using questionnaires.

Main Results:

• No significant differences in EEG power were found between groups.
• Significantly increased bilateral, intrahemispheric, posterior EEG coherence in alpha and beta bands was observed in both non-abstinent and long-term abstinent alcoholics.
• This increase in coherence was particularly pronounced when depression was included as a covariate.

Conclusions:

• Increased EEG coherence (cortical synchronization) may be an endophenotype for alcoholism.
• This finding, potentially linked with increased depressiveness, suggests a role for GABAergic and/or glutamatergic neurotransmission in alcoholism vulnerability.