Cannabis is a factor that can trigger a psychotic outbreak.And if in your genes you have susceptibility to schizophrenia as well.Bipolar disorder is rather genetic, also influenced by substance consumption. Diabetes or tobacco themselves do not trigger or produce a mental illness, rather than the stress that can be controlled by glycemia (which depends on how each person manages) and the stress that may mean quitting smoking.If you already have in the genes tendency to a mental illness and substance consumption, you have diabetes or not, it is more likely to develop them.