What can trigger somebody to become schizophrenic?

No real triggers: It is at times common for someone with schizophrenia to relate back to something that caused or started it, whereas there are really no known triggers. One main factor seems to be age, as schizophrenia definitely, and for reasons not well understood, begins in the late teens or early 20s. There is new evidence which suggests that smoking marijuana can contribute to the onset for those predisposed.