Yes, I truly believe that it is genetic. My uncle's first wife, who is "normal", has a brother who is schizophrenic. Unfortunately, my uncle's kids by that wife all suffer from some form of mental illness. It skipped a generation in their case. One is schizophrenic, the other has some type of condition that she has the mental capacity of a young teenager (she's in her 30's), and their third child also has a mental condition, not sure what it's officially called...bipolar maybe?. I really don't know who else in my ex-aunt's family suffers from mental illness, but it appears to be genetic in her family.