A recent Cardiff University study has linked marijuana usage to far greater odds of psychiatric conditions involving psychosis later in life; and yet for every one study such as this, it seems that there are two studies extolling the virtues of medical marijuana. So should we be burning fields of grass, or planting more?

OK, I know that as soon as I start to talk about marijuana I begin to come across as some kind of governmental propaganda "reefer madness" anti pot fascist, but there are some things that need saying.