Human sleep and EEG through a cycle of methadone dependence.

The effects of oral methadone on EEG and sleep were studied in 6 male postaddicts. Continuous nocturnal measurement of EEG, EMG and EOG was used to define sleep patterns. Period analysis and power spectral analysis were performed on each 8 min sample of daytime (eyes closed) EEG. Both sleep and EEG were studied during a predrug control period, during the methadone induction phase (45-60 mg/day), stabilization phase (100 mg/day), and then 6; 10, 13, 18 and 22 weeks after withdrawal. One subject did not complete the last two withdrawal sessions. While on methadone, subjects reported that they slept more and also showed an increase in slow wave activity and a decrease in fast wave activity of their EEG during this time. Nocturnal sleep was not markedly altered during the chronic administration of methadone. Subjects reported an increase in dreaming soon after withdrawal, and then 3-5 weeks of nocturnal isnomnia. At the 6th week after withdrawal, slow wave activity in the daytime EEG was decreased, fast wave activity was increased, and mean EEG frequency was increased. REM sleep and delta sleep were increased during withdrawal. These data provide further evidence that chronic administration of narcotic analgesics may induce persistent functional changes in the central nervous system.