I've noticed that sleeping 4-6 hours is enough after a day of using speed (moderate use - but still like a party drug, not medicinal). Now, this research shows that a dopamine kick can help you switch to REM sleep in an instant. www.drugdiscoverynews.com/a-dopamine-kick-switches-non-rem-to-rem-sleep-15412 Since speed is mainly just releasing dopamine for you, could it be that by the time we get to bed we're going straight into REM? Thus we get the "useful" part of sleeping while skipping the non-REM? Anybody else notice this?