As a therapist, I am much more concerned about a person's experience of depression, rather than the chemical make-up of one's brain. While I am sure that there are differences between the brains of a depressed individual and a non-depressed individual, just as there are brain differences between all differing mental states, it is in the person's experience of depression where we may find a way out of the darkness. When we look at depression, or any other challenging mental state, as some kind of "mental illness" or chemical imbalance, we take the person out of the context of their life and instead of helping that person work their way through this challenge and into a way of experiencing themselves and the world that is powerful, authentic, and alive, we leave them at the mercy of chemistry.
I have worked with many depressed individuals and while each person's struggle with depression is unique, there are some common elements. A common element in the experience of depression is constriction. Constriction can come in many forms: constriction of feeling, constriction in the form of physical tension in the body, constriction in motivation... When depressed, people often lose connection with their sense of joy or pleasure in themselves, others, and the activities of life. Often, there is a sense of inertia, of being held down by a weight and a sense of pointlessness and/or hopelessness. What is the point in doing anything, if one cannot even imagine it being enjoyable or leading to a better life in any way? Another frequent aspect of depression is intrusive negative thoughts - criticizing, deflating, and reminding us of old hurts. In depression, these thoughts overwhelm our mental space, running on loops that seem endless.
To escape the constriction and the rumination, we may employ a variety of strategies: isolating ourselves, sleeping all the time, abusing drugs and/or alcohol, comforting with food, binging on shows, video-games, or porn. These strategies, while understandable and perhaps even relieving in the short-run, don't alleviate the depression in the long-run because they avoid, rather than address, the roots of the constrictions at the heart of depression. To get through depression, one must turn into their experience so that one can reconnect with those aspects of themselves which have become choked-off. Often, the process of reconnecting with one's self involves facing things which may be painful or scary, but doing so is often a key part of freeing one's self from depression and creating a life that is vital and authentic.
Doing combat with depression can be difficult and can have its ups-and-downs, but it does not have to be a lonely battle. A competent therapist can be a powerful ally in the fight against depression, by helping you to untangle yourself from and make sense of your experience, begin to establish more of the life that you want, and develop strategies to help you deal with any sense of overwhelm. In the grip of depression, it may be hard to see a way out, or to even remember what it was like to feel differently, but there is hope. Sometimes, the best way to get out of depression is to find an ally who can help you find your way through by getting more into it.