Opioids are CNS depressants, and do counteract most of meths effects, but they aren't effective sleep-aids. It even prevents some people from actually falling asleep, instead they stay partially awake, but in a trance(the nod). Benzodiazepines are a stimulants users best friend, after the stimulants themselves ofcourse. Hypnotic benzodiazepines are obviously the best sleep-aids, they are Normison, Rohypnol, Loramet, Dormicum etc. Anxiolytic benzo's have hypnotic effects as well, but are less effective in helping you fall asleep than the hypnotic benzodiazepines. Anxiolytic benzo's are Xanax, Lexotanil, Valium, Temesta, Seresta, and partially also Rivotril. Rivotril relaxes the muscles very well, and is the best benzo for this purpose, after Rohynol. It effectively takes away any body tensions, which contributes in helping you fall asleep.