Marijuana may increase psychosis risk

[Professor S]

The numbers in the quote Bond posted are some of the most irresonsible I;ve ever seen by a scientist. He mixes different numbers together.

For example, Zammit said the risk of developing schizophrenia for most people is less than 1 percent. The prevalence of schizophrenia is believed to be about five in 1,000 people. But because of the drug's wide popularity, the researchers estimate that about 800 new cases of psychosis could be prevented by reducing marijuana use.

So its 5 in 1,000 normally (.5% chance, BTW), but reducing weed use would stop 800 new cases? 800 new cases out of how many in the pool? 10,000? 100,000? 1,000,000? The world?

There is also the argument of causation vs. correlation. They are including depression in their numbers. Now are they depressed due to the weed, or do those that are depressed tend to gravitate towards its use?

There are so many questions to consider.