Using marijuana can impair momentary memory, verbal abilities, decision, distort perception, and impair driving performance. Heavy marijuana use impairs a persons ability to create memories, remember occasions, or shift focus from 1 thing into another. Users that have taken high doses of this medication may experience severe toxic psychosis, including hallucinations, delusions, and depersonalization (a lack of this sense of personal identity or self-recognition).In a couple of minutes a people h...