Changes in resting EEG following methadone treatment in opiate addicts

Objective: This study investigated the electrophysiological activity associated with methadone maintenance treatment (MMT). Methods: The resting EEG spectrum of beta (14.5-30 Hz), alpha (8-13 Hz), theta (4-7.5 Hz) and delta (1.5-3.5 Hz) rhythm were measured in 32 patients undertaking chronic MMT, 17 opiate users and 25 healthy volunteers. Differences in the EEG components of each group were evaluated using a repeated measures Analyses of Variance (ANOVA). Post-hoc comparisons were Bonferroni corrected. Results: Our results show that either patients undertaking MMT or active opiate users exhibited a significant increase in the power of beta and theta bands relative to healthy control subjects. However, the spectral power of patients undertaking MMT fell between that of current opiate users and healthy control subjects on many regional EEG measures. There was an inverse correlation between the power of beta or theta bands and cognitive performance. Conclusion: The abnormal neural electrical activity present in those still using illicit opiates might be reduced following MMT. Significance: The present findings provide further support for MMT of opiate dependence and demonstrates potentially positive effects of substitution treatment on brain function. (C) 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.