“In what could turn out to be a groundbreaking study, a group from Neuroscience Research Australia has been examining if cannabidiol – one of the main ingredients in cannabis – could reverse some of the symptoms of dementia, specifically Alzheimer’s disease. Early research for the study has found that it does.” 
“In the study, mice were injected with a disease analogous to Alzheimer’s, and then given doses of cannabidiol. The results so far are quite drastic; “It basically brings the performance of the animals back to the level of healthy animals,” said Tim Karl, one of the study’s researchers.
He goes on, “You could say it cured them, but we will have to go back and look at their brains to be sure.”
As part of the research, the group also found that treating certain harmful cells associated with Alzheimer’s with cannabidiol reduced the amount of the harmful protein that they produced.”
http://thejointblog.com/new-study-shows-cannabis-may-reverse-symptoms-of-dementia/