I agree with zinco

I believe that the entire realm of the so called mental illness is genetic and is related to DNA. But because of the stigma it is put down to "brain chemistry" and gets a band-aid slapped on it in the form of medications. There is more and more evidence that connect mental illness with other physical illness like MS and others. There is evidence that the brain can change from thinking but that's not the total answer.

CBT can help but in a limited way. It can help make lifestyle changes that make it easier to handle the illness. It can help change the way a person reacts to the manifestations of MI like depression but I don't believe it is going to solve depression or any other MI on an organic level.

For some doctors they think the cart came before the horse by insisting that the way you think causes the depression and that causes the changes in the brain. I agree with zinco that the illness comes first and that causes the change in thinking that changes the brain. The answer is looking at the whole body not just the brain. In mathematics if you take out any part of the equation the entire thing is invalidated. The answer to MI will be found in science not conjecture and guess work.