Neurophysiological signs of cocaine dependence: Increased electroencephalogram beta during withdrawal

To determine whether a central nervous system marker of cocaine dependence might exist, the resting electroencephalogram (EEG) of 33 drug-free, cocaine-dependent men (DSM-III-R criteria) was compared with two control groups [nondrug group (n = 10) and drug group who abused drugs, but were not cocaine dependent (n = 20)]. The EEG was recorded from eight sites after about 10 days of monitored abstinence (range 4–15 days) on a closed research ward for the drug-using individuals. The EEG was recorded for the nondrug control group as outpatients. The drug history was determined by the drug history questionnaire and a medical screening interview. The percent of EEG beta activity for the cocaine-dependent subjects was greater than that of both control groups (p< .05) as well as a normative database (HZI: Tarrytown, NY). The percent of EEG beta in frontal and central areas of the cocainedependent individuals was correlated with the frequency of cocaine use during the last 30 days. High levels of EEG beta may be a neurophysiological withdrawal sign in cocainedependent men.