IIRC, there's also a very high correlation between schizophrenia and early substance abuse/overuse in general (such as high alcohol/caffeine use). Are these substances causal too?
As we know, global warming has a positive corellation with a decline of a pirate activity, but nobody yet discovered the cause.
* as a person who at least read some things on it - it should be really described as 'attempts at s.m.' but here we are