Neuropsychological functioning in opiate-dependent subjects receiving and following methadone maintenance treatment.

Department of Psychiatry and Behavioral Sciences, Beth Israel Medical Center, Albert Einstein College of Medicine, New York, NY 10003, USA.
Drug and Alcohol Dependence (Impact Factor: 3.28). 11/2006; 84(3):240-7. DOI: 10.1016/j.drugalcdep.2006.02.006
Source: PubMed

ABSTRACT An accumulating body of research suggests that former heroin abusers in methadone maintenance therapy (MMT) exhibit deficits in cognitive function. Whether these deficits are present in former methadone maintained patients following discontinuation of MMT is unknown. This study tests the hypothesis that former heroin users who have detoxified from methadone maintenance therapy and are drug-free have less pronounced cognitive impairment than patients continuing long-term MMT.
A series of neuropsychological tests were administered to three groups of subjects: 29 former heroin addicts receiving methadone maintenance treatment, 27 former heroin addicts withdrawn from all opiates, and 29 healthy controls without a history of drug dependence. Testing included Wechsler Adult Intelligence Scale-Revised Vocabulary Test, the Stroop Color-Word Test, the Controlled Oral Word Association Test, the Benton Visual Retention Test, and a Substance Use Inventory.
Both methadone-maintained and abstinent subject groups performed worse than controls on tasks that measured verbal function, visual-spatial analysis and memory, and resistance to distractibility. Abstinent subjects performed worse than their methadone maintained counterparts on tests measuring visual memory and construct formation. Cognitive impairment did not correlate with any index of drug use.
We confirmed previous findings of neuropsychological impairment in long-term MMT recipients. Both patients receiving MMT and former heroin users in prolonged abstinence exhibited a similar degree of cognitive impairment. Cognitive dysfunction in patients receiving methadone maintenance may not resolve following methadone detoxification.

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    ABSTRACT: 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.
    Clinical Neurophysiology 09/2014; · 2.98 Impact Factor
  • Procedia - Social and Behavioral Sciences 01/2011; 30:1748-1751.
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    ABSTRACT: Methadone maintenance treatment (MMT) has been used to treat opiate dependence since the mid-1960s. Previous studies have investigated the effects of methadone on cognitive function however the findings have been inconsistent. Some report a complete absence of deficits while others report different types of cognitive impairment. Our research aimed to investigate the effects of MMT on cognitive function by comparing the performance of patients currently enrolled in MMT (n=32) with opiate-dependent subjects (n=17) and healthy control subjects (n=25) on a computerised neuropsychological test battery. Both the patients undertaking MMT and the opiate users showed less efficient interaction between visual searching and manually connecting digits and letters during the Switching of Attention Task than the healthy control subjects (F(2,64)=3.25, p=0.05), which indicates deficits in information processing. Nevertheless, the performance of the MMT group was similar to that of healthy control subjects in all other tasks, in contrast to the group of opiate users who performed poorly when compared to healthy control subjects during tests of attention (mean difference (MD)=2.8, 95% confidence interval (CI) (0.9-4.7), p=0.001) and executive function (MD=5.9, 95% CI (1.3-10.5), p=0.007). These findings suggest that cognitive function in patients undertaking MMT is improved compared to those dependent on illicit opiates.
    Journal of Psychopharmacology 06/2014; · 2.81 Impact Factor

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