Induced theta oscillations as biomarkers for alcoholism.
OBJECTIVE
Studies have suggested that non-phase-locked event-related oscillations (ERO) in target stimulus processing might provide biomarkers of alcoholism. This study investigates the discriminatory power of non-phase-locked oscillations in a group of long-term abstinent alcoholics (LTAAs) and non-alcoholic controls (NACs).


METHODS
EEGs were recorded from 48 LTAAs and 48 age and gender comparable NACs during rest with eyes open (EO) and during the performance of a three-condition visual target detection task. The data were analyzed to extract resting power, ERP amplitude and non-phase-locked ERO power measures. Data were analyzed using MANCOVA to determine the discriminatory power of induced theta ERO vs. resting theta power vs. P300 ERP measures in differentiating the LTAA and NAC groups.


RESULTS
Both groups showed significantly more theta power in the pre-stimulus reference period of the task vs. the resting EO condition. The resting theta power did not discriminate the groups, while the LTAAs showed significantly less pre-stimulus theta power vs. the NACs. The LTAAs showed a significantly larger theta event-related synchronization (ERS) to the target stimulus vs. the NACs, even after accounting for pre-stimulus theta power levels. ERS to non-target stimuli showed smaller induced oscillations vs. target stimuli with no group differences. Alcohol use variables, a family history of alcohol problems, and the duration of alcohol abstinence were not associated with any theta power measures.


CONCLUSIONS
While reference theta power in the task and induced theta oscillations to target stimuli both discriminate LTAAs and NACs, induced theta oscillations better discriminate the groups. Induced theta power measures are also more powerful and independent group discriminators than the P3b amplitude.


CONCLUSIONS
Induced frontal theta oscillations promise to provide biomarkers of alcoholism that complement the well-established P300 ERP discriminators.
Andrew
Colin
C
Neurobehavioral Research Inc., Honolulu, HI 96814, USA.
Fein
George
G
D000328:Adult; D020268:Alcohol-Induced Disorders, Nervous System / Q000175:diagnosis* / Q000503:physiopathology; D000437:Alcoholism / Q000175:diagnosis* / Q000503:physiopathology; D000465:Algorithms; D001683:Biological Clocks / Q000187:drug effects / Q000502:physiology; D015415:Biomarkers / Q000032:analysis; D001921:Brain / Q000187:drug effects* / Q000503:physiopathology; D002492:Central Nervous System Depressants / Q000009:adverse effects; D000431:Ethanol / Q000009:adverse effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D013826:Theta Rhythm / Q000187:drug effects*
D015415:Biomarkers; D002492:Central Nervous System Depressants; D000431:Ethanol