What happens to the body and the brain physiologically if depression is left untreated?

Question

I am doing some research and I was wondering what can occur to the brain and/or body if the person is never treated for depression? Scenario: The depression was brought on by the sudden death of a close friend. I would first like to say I do know there are stages of grief that one must go through in order to heal. I want to point out the depression stage. If one becomes trapped in that stage and nothing is done to try to get past it, eventually what effects would it have on the body and brain from a physical stand point? I always thought after some point it could take a toll on the body, but what is happening from within.

Answer 1

It's well accepted that almost all mental such illnesses, including depression are caused by structural abnormalities and mis-wiring in parts of the brain which can cause neurochemical imbalances. Depression's almost always caused by cortisol (the stress hormone) being present in the brain due to prolonged stress, and eventually changing the networks, cutting off connections and decreasing the amount of white matter (the connections) in the brain. Making it hard for the part of the brain that generates emotions (limbic system and sub-cortical regions), to connect with the part of the brain that uses and controls emotions (prefrontal cortex).

Fortunately, the brain can physically change its structure back to normal through time through the help of treatment (i.e. medication, psychotherapy etc...) due to a phenomenon called neuroplasticity. Eventually the cortisol levels will revert back to normal, along with neurotransmitters, neurohormones, and neuropeptides.

Answer 2

Generally brain activity is terminated via massive head or spine trauma or the sudden decrease in the amount of oxygenated and/or nutrient rich blood reaching it, or again the increase of toxic chemicals in the bloodstream to unacceptable levels.

This will almost always be self inflicted.

This is merely the most advanced stage of depression. And I'm only half joking.

Answer 3

If say a lady goes through menopause and goes into manic depression, left untreated she could go into a deep state and not come out. This could lead to other problems, not withstanding suicide.

Answer 4

take a dirty sock
turn it inside out

sock looks fine
for a while

the dirt continues to corrode/decay away from the inside
which was initially/originally the outside

both inside and outside are now damaged