Right... I agree that psych problems could be based in genetics, its just not my field. But these things can also be environmental, developmental, epigenetic. They can also be mixtures of all of them. I was just saying that we're probably not going to have a genetic test for psych conditions and be able to eliminate them. Sure, maybe one or two combinations of mutations could be screened for, but never most, no matter how far genetics research goes.
It's like a rocket. You need all the parts of a rocket to work or you won't get off the ground. If you are really unlucky, it may even explode
With psychiatric disorders, it's similar. Break a few choice genes and the whole system goes to shit. But unlike a rocket, it keeps working, just not in the fashion that other brains works. So you get some kind of disorder like schizophrenia or bipolar.
I was involved in a few projects where they were mapping schizophrenia with SNPs. Looking at the data, it's clear that some individuals cluster around certain SNPs...but most of them are scattered everywhere. Lots of things can cause schizophrenia, because it really isn't a single disease but a set of common symptoms.