Hey akv272!
Research would tell me that Marijuana
abuse has an effect of REM suppression and taints your ability to recall dreams.
Personal experience (and the wise words of my professor) tells me it's
not so black and white...
I used to be a heavy smoker. Nowadays it's more of a novelty, and after years of experimenting with its effect on my mind, body, academics, social life and
life in general I can say with confidence that whilst daily smoking isn't ideal for maximising the productivity and capacity for most people, it certainly isn't completely detrimental when used in
moderation. Moderation is the key here.
Anyway...
Certain chemicals which are present in cannabis have a negative effect on short term memory. Other compounds in specific strains actually have other effects on your dreams. Now think, if you go to sleep high, you won't remember any of the effects because of the effect on your memory, but that doesn't mean those other effects didn't come about. If you leave it a few hours before sleeping for your brain to adjust, many people tend to experience very vivid dreams. You actually remember the effects on your dreams and can observe how these chemicals affect your dreaming mind long after the immediate effects have worn off.
Prolonged use of marijuana before sleep will affect your ability to recall dreams... Because everyone is different, weed will effect everyone slightly differently. Going to sleep high everyday will just put a huge barrier between you and dream recall, but I find occasional use to have no detrimental effects on my dreams.
Just my 2 cents