I have just started Paul Bloom's Psychology Course on academicearth.org. The first lecture proper (see below) discusses the brain.
It begins with the problem of Dualism. The separation of the soul and the body. From Descartes' famous 'I think therefore I am', and the idea that you don't need to believe that any part of your body exists to know that you are conscious.
It is hard to start believing that everything you are is not separate from your body. That you are your brain. That as your brain gets damaged, part of you goes away. This doesn't feel nice. We like to think of ourselves as having this indestructible separate self that exists separately from our bodies.
But, that is also a part of why mental illnesses are so hard to handle. When someone has a sore leg, or the flu, or cancer... 'they' don't disappear. We can still be supportive. What gets difficult is when someone's character changes when they get hurt. When they forget who you are. When they stop being dependable. When they start lying. When they lose the ability to focus on the things that are important to them.
All this stuff is tough to swallow. But by the same token, I find it empowering. If you start looking at the world in a scientific way, you start realising that things either have a solution or they don't. If they do, there is often something you can do about it.
If you are unhappy, a good place to start would be getting fit, eating right, cleaning the environment you live in, living somewhere you like, spending time with people you love, training yourself to not get irritated with things that you can't control, and doing a job you enjoy. These are all things under your control. If you do that are still not happy, then perhaps I am wrong.
Maybe the link is tenuous, but I don't think so. A lot of 'dualist' approaches apportion blame. 'This is the situation that I am supposed to be in, let me grin and bear it stoically.' In the main, we have far more control over the physical world than we probably are prepared to admit.
The bit that is scary is that this is all we have, and it is fragile... and it can break. So best we look after each other.