One of the most common home-remedy uses for cannabis is as a natural sleep aid or cure for insomnia. There is no shortage of discussion on the matter—pitting the power of Cannabis sativa against that of C. indica, weighting the virtues of eating versus smoking, and calibrating the optimal balance between THC and CBD. Much of this speculation is impassioned, some if it is persuasive, and all of it is anecdotal.
On the other hand, the science is pretty meh. In lab mice, cannabis has been observed to increase slumber duration. In people, it tends to make falling asleep easier and to deepen sleep. But it doesn’t seem to lengthen overall sleep, and it even shortens the REM phase. A number of studies have shown that cannabis improves sleep in general, but one comparison study showed that it was less effective than amitriptyline, a not-particularly impressive aid.
Longterm use of cannabis may lessen the drug’s effects, and withdrawal can cause not only insomnia but also a rebound REM effect that temporarily produces more vivid and frequent dreaming.
If it’s anxiety that keeps you up at night, the intoxicating and relaxant properties of cannabis can help that, much as a slug of whiskey would. But, unlike cannabis, booze will shorten your slumber and make it shallower. So if you do want to drug yourself to sleep, pick up the bong, not the bottle.