Recent work in the field of mental health has shown that the chemical imbalance theory of mental illness that prevailed the last 10 years was wrong. It has also been shown that the brain is not fixed but fluid. It used to be thought that we couldn’t grow new nerve cells once the brain was formed. We now know that to be untrue. In fact the most recent studies show one pathway to major depression is in fact caused by cell loss in the regions that control learning and alertness. Any exposure to prolong stress causes this type of cell loss. It is protective in the way that if you are being exposed to sever prolonged stress your brain adapts in such a way that you no longer pay attention to it. Only you no longer pay attention to anything else as well.
Antidepressants have been shown to cause a cascade of neuro-chemicals that as a result stimulate cell growth in these areas essentially waking up the brain. Attention to the environment thus learning is once again reinstated.
I like the adaptive, learning, and attention approach a lot better as the chemical imbalance theory was to passive. It implied you were broken and needed the medication to be ok. There was no fix. In this new theory the medication helps wake a person up to their environment but that’s only part of the work. One still needs develop skills to deal or they will just shut down again over time. It’s a help you to help yourself theory. This is infinitely more user friendly.