Some research exists[1] though limited to testing with THC, so it wouldn't be strictly accurate to say 'cannabis' (for example, it would also be worth doing a similar study on CBD, as it has quite a few interesting properties as well).
I agree. I'm a sample of one, but when I used to smoke cannabis in my teens it definitely made me sleep dreamless and usually wake up pretty groggy as well.
Since CBD only products (< 1% thc) have become legal in Switzerland, I've been using them to handle anxiety and one of the upsides is very refreshing sleep + more dreams.
Generally heavy cannabis users don't dream as often or vividly as normal. One of the primary symptoms of cannabis withdrawal is extremely vivid dreams. I don't know if there's been any formal studies on this in particular, but I've heard enough independent anecdotes, that I'm convinced there is some relation.
Above was just the subjective part, there have been studies on the objective effects of cannabis on REM sleep, where it appears to decrease total REM sleep duration.
As far as the implications of this go, your guess is as good as mine.
Not a cannabis user, but I hardly ever remember my dreams. Maybe one every 1-2 months if I'm lucky. I wonder if that means that there is something wrong with my sleep.
Remembering dreams as vivid and not remembering the that much does not mean dreams are not vivid. Deep sleep hides those dreams or is there some empirical data?
