Effects of chronic treatment with methadone and naltrexone on sleep in addicts

Previous studies have described sleep disturbance secondary to chronic opiate use and abuse. Drug-dependency insomnia is of interest because chronic sleep disturbances can promote depressive symptoms which could lead to a drug relapse. For the first time we compared the polysomnographic parameters of 10 methadone-substituted outpatients and 10 naltrexone-treated outpatients. Methadone (mu-opioid agonist) produced a marked fragmentation of the sleep architecture with frequent awakenings and a decrease in EEG arousals. In comparison with methadone and controls, the naltrexone (mu-opioid antagonist) group showed the shortest sleep latency and the longest total sleep time. These data indicate that mu-agonists and mu-antagonists have different effects on sleep. The implications, especially the involvement of opioid-dopamine interactions on sleep and movements during sleep, are discussed.