What is the neuro-physiological explanation for depression?

Answer 1

Many modern antidepressant drugs change levels of certain neurotransmitters, namely serotonin and norepinephrine (noradrenaline). However, the relationship between serotonin, SSRIs, and depression usually is typically greatly oversimplified when presented to the public, though this may be due to the lack of scientific knowledge regarding the mechanisms of action. Evidence has shown the involvement of neurogenesis in depression, though the role is not exactly known. Recent research has suggested that there may be a link between depression and neurogenesis of the hippocampus. This horseshoe-shaped structure is a center for both mood and memory. Loss of neurons in the hippocampus is found in depression and correlates with impaired memory and dysthemic mood. That is why treatment usually results in an increase of serotonin levels in the brain which would in turn stimulate neurogenesis and therefore increase the total mass of the Hippocampus and restores mood and memory, therefore assisting in the fight against the mood disorder.
Hope this helps a little.

Answer 2

There are many explanations, all of them physical. What chemicals our brains produce determines everything from our appetite and sex drive, to our moods and perceptions. The two most researched and widely known are dopamine and serotonin.

They are both required in differing ways to feel good, but serotonin in particular is one responsible for whether we can experience pleasure, or feel anything at all if it comes to that. Often people with depression lose interest in everything, have no energy, and wonder if life is really worth living. They are not feeling sorry for themselves, they are literally, physically, incapable of responding normally any more. .

This is because depression is caused by a severe lack of serotonin, (it is the main one, anyway) which is why they call it "clinical depression" to differentiate it from just feeling sad, which is normal, if unpleasant at the time.
Serotonin is not actually given to people when they take anti-depressants ~ what the most prescribed SSRIs (Selective Serotonin Re-uptake Inhibitors) do is stop any serotonin which IS released by certain parts of the brain from being re-absorbed, and keeps it in the system where it can be used.

A flood of this hormone happens when we fall in love, to give the biggest example, and to a greater or lesser degree when we do anything that gives us pleasure.

Some illicit drugs do the same thing, and since they very quickly destroy the brain's ability to produce more, the body becomes progressively more desperate to replace it.

So ~ everything from a slight feeling of anxiety to full blown panic attacks, obsessive-compulsive disorders to crippling depression are all caused by the physical brain being unable to make the proper neurotransmitters available.

If you want to know more about which areas of the brain do what, try typing 'The Biochemistry of Neurotransmitters' into Google or whatever you use; or just type 'neuroscience of depression' or any variation you can think of. There are some excellent sites for both the layman and the professional.

Hope this helped a little.

Answer 3

Chemical imbalance in the brain, esp. Serotonin, the feel good chemical. Anti-depressants try to correct these imbalances though there are many other alternative therapies which tackle the problem more holistically.

Answer 4

The slowing of the brain's ability to transport serotonin through its synapses.