http://news.bbc.co.uk/2/hi/health/6606931.stmWell, duh!
Cannabis was famously used in France in the 19th century by a doctor who believed that taking cannabis in large doses simulated psychosis and if nothing else gave him insight into what psychosis might be like. Note that this was eating extremely high doses - and if you've ever eaten too much pot, you probably know that it is not generally pleasant. From what I understand, when eaten, THC actually becomes more potent - you can get both higher and the high lasts longer. That said, I don't know anyone who trips using marijuana. Most people prefer the pleasant buzz you get from smoking.
While marijuana has been linked with psychosis since a Swedish study of about 1970, the connection is only strong if you're a drug warrior. For example, a New Zealand study of a few years ago reported a 300% increase in the chances of becoming psychotic if you smoked marijuana during adolescence.
Interestingly enough, however, Norml says that schizophrenia (the major psychotic disorder) rates have fallen by about 40% or the last 40 years - the same time in which so many kids took up smoking pot.
So what does this all mean?
1. Large doses (intravenous cannabis?) have always made people act goofy.
2. Researchers make money by finding danger associated with illegal drugs.
3. Alcohol is truly poisonous, both short term and over the long haul - while marijuana is suspected of long term harm associated with massive doses.
So which drug gets sold legally?
Stay safe!