Cannabis, whether in the form of recreational, medical or illegal "dirt-weed," is a renowned sleep aid. As far as dreaming and nightmares while sleeping soundly under the influence of marijuana, most users offer little no complaints.
Vivid or even lucid dreaming is not an uncommon side effect, however. Due to THC and other psychoactive components of cannabis, an overactive mind is to be expected, especially during those quiet hours of introspection before bed. Many of us, especially those smoking for mental health reasons, are very familiar with the flaws of the human psyche, including the surge of life regrets, sorrow, and general disposition. Marijuana can both cure and aggravate this phenomenon.
While smoking cannabis before going to bed can result in a soothing, calming slumber, some tokers have reported paranoia and anxiety while high, which doesn't help with the night-time terrors. After actually drifting off to sleep, this anxiety and paranoia might carry over and disturb an otherwise restful night's sleep. As the subconscious still experiences these perturbed feelings, a user's dreams are naturally to be affected, despite the body's sleeping state. Users have experienced lucid dreaming, dying in their dreams, surreal nightmares, and overall troubled sleep. Some claim a prolonged REM sleep cycle.
On the other hand, many smokers also claim not to dream at all while smoking marijuana. The calming effects of Cannabis can definitely counteract the aforementioned problems with sleep. Cannabis can induce a totally dreamless slumber which users wake up from without any knowledge of ever even having gone to sleep!
On the contrary, most smokers experience nightmares and restless sleep when abstaining from smoking cannabis. During the first few weeks of not smoking marijuana, there are countless accounts of intense dreaming, waking nightmares and vivid, unnerving imagery. Perhaps this is the most common experience regarding the use of cannabis in relation to sleep. "Dreams got more vivid when I stopped smoking pot," says critically acclaimed rapper and cannabis user, Earl Sweatshirt. In short, if one is experiencing nightmares as a result of a tolerance break, probation sentence, or whatever reason there could possibly be to abstain from the all-healing plant, it is likely because of said break in consumption.
In conclusion, marijuana's effects on dreaming differ from person to person, but the general consensus is that consuming cannabis is beneficial to the overall quality of sleeping for an individual. Is it any surprise? Smoking seems to help everything. As an additional note, cannabis edibles are especially powerful when combatting night-terrors!