EEG of chronic marijuana users during abstinence: relationship to years of marijuana use, cerebral blood flow and thyroid function.
OBJECTIVE
Marijuana abuse is associated with neurological changes including increases in frontal EEG alpha during abstinence. Research is needed to assess to what extent these EEG patterns are indicative of cerebral perfusion deficits.


METHODS
We recorded the resting eyes closed EEG of 75 abstinent marijuana users and 33 control subjects. Fifty-six marijuana users used marijuana for less than eight years and 19 used for eight years or more. The EEG evaluation occurred within 72h of admission to an inpatient unit. Fifty-nine marijuana users remained abstinent for a month and were tested twice. Supplemental psychological and physiological data were also collected.


RESULTS
Log alpha2 and beta2 power at posterior sites were significantly lower for the marijuana abusers that used eight years or more than the other marijuana abusers and the control subjects. These EEG changes continued for the month of abstinence. The marijuana users who used marijuana for more than eight years, also, had lower heart rates and thyroid function (T4) compared to the other marijuana users and the control subjects.


CONCLUSIONS
Chronic marijuana use was also associated with reduced EEG power in alpha and beta bands at posterior sites. These reductions in EEG power appear to be related to cerebral perfusion deficits and/or thyroid function in marijuana abusers.


CONCLUSIONS
Our results suggest EEG, cerebral blood flow velocity, cardiovascular and thyroid function alterations in marijuana abuser with an extended period of use. These alterations reflect under arousal in these systems.
Molecular Neuropsychiatry Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, 5500 Nathan Shock Drive, Baltimore, MD 21224, USA. rherning@intra.nida.nih.gov
Ronald I
RI
Herning
Warren
W
Better
Jean L
JL
Cadet
D000293:Adolescent; D000328:Adult; D000513:Alpha Rhythm; D001783:Blood Flow Velocity / Q000187:drug effects; D001931:Brain Mapping; D002560:Cerebrovascular Circulation / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008297:Male; D008385:Marijuana Smoking / Q000503:physiopathology*; D013057:Spectrum Analysis; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology*; D013961:Thyroid Gland / Q000187:drug effects / Q000503:physiopathology*; D013997:Time Factors; D018616:Ultrasonography, Doppler, Duplex