Now I think one more question I have is that has it been shown that depressed people can have few genes responsible for brain loss (meaning, that even though he/she is very depressed, that he/she isn't going to lose much of his/her brain)?

Thats correct!

But are there depressed people with none of the GATA1 genes that result in smaller brain mass in the prefrontal cortex? Or are these genes necessary to survive?

No we all have these genes --we must have them for survival.
This is why I say it gets complex---bdnf --gene is found in more than the brain -- however its s secret protein or nerve growth for the brain. Its about increase these level of bdnf---low level indicates in other disease as well ocd,alheimzers,hunnington and dementia ---this is where i indicated before the studies in depression decrease in the bdnf gene to the hippcampus to shrink --hence stress and depression decrease expression of bdnf. taking anit dep meds,exerise,other therapy increase its level of the bdnf level.

Even the GATA1 gene we all have as well (the bad gene that was stated in that article you posted to be responsible for brain loss in the prefrontal cortex)? I'm sorry if it seems I'm asking the same questions, it's just that I have things on my mind with this.

Now it stated in that article that a loss of brain mass in the prefrontal cortex occurs. But you said that there is evidence that just a loss of activity in that area occurs and not a loss of brain mass in that area (shrinkage). Therefore, due to this contradictory information, is it unknown if a loss of brain mass occurs in that area through depression?

Like here it says that this shrinkage is known to occur in depressed people (the 5th paragraph of this article):

http://www.dailymail.co.uk/health/ar...ink-brain.html

But as stated before, you said there is information that contradicts this. And again, leading back to the question of is it unknown whether this shrinkage actually occurs in depressed people. I do have chronic major depressive disorder, and is there information out there that even shows people who have major depression have a normal sized prefrontal cortex or even a bigger one? Again, just wanting to learn in asking these questions.

The size of the hippocampus varies from one person to another regardless of depression, much like height and foot size vary. Several studies indicate that genetics determines about half of the size variation in the hippocampus.

so yes depression is assoc with a smaller hippocampus--but delayed treatment shows might be assoc with further shrinage--and the study shows antidepressants have been shown to stop further shrinage.

its like what came first chicken or egg .

the brain shrinks for everyone 1.9 % every 10 yrs then 1% every yr over 64 ---here the point yes it plausable in a larger % of chromic depression that the area of the hippocampus shrinks but seems to stop once medicated most eveidence appears it comes from the stress hormone released that does this damage.

white matter --is composed of nerve fiber

grey matter is made up of cell bodies

what has been studied in people with know depression and changes in brain images of people changing going thru dramatic life events --divorce,illness ,loss of job ,death of love ones --show shrinkage-- after these events--- where before areas were larger ---then it led me to ? if its just the way depressed ppl brain is like if ur born with it-- if thats the case why does it stop or changes with medication. That why i think it complicated. It not the same like a brain shows perm damage as it does with alheimzers or huntingtons .

And then you have people like me who pickled their brain for years before they got "it" and got sober! LOL Talk about killing brain cells!!! LOL

Lee--Thanks for your humor (lol)

Now how do you know that it's possible that a person can experience more depression in his/her life through the shrinking of his/her brain if it hasn't even been proven?

Do we even know that it's possible that someone can experience more depression through this shrinkage?

Hi Matt,

To answer your first question --again there is evidence shows shrinkage --but once proper medication and treatments are done the damge stops some cases possiby reversed .

To your 2nd question yes as well --but only if left untreated why because the affect on genes and the hormones levels like cortisol.

In depression, the body’s stress-response systems are going nonstop. Hormones (like cortisol) stream through the body The effects of this long-term stress response are devastating for the brain and the body. The body responds by increasing adrenaline, by elevations in blood pressure, by increased blood levels of sugars and fats.

The brain responds by having its alarm systems in an always-on. The amygdala, the brain’s panic system, actually grows in size! The hippocampus, the brain’s center of working memory, and the prefrontal cortex, the area of planning and memory do shrink. Chronic depression is very toxic for your brain.

DD is also toxic for your body. People who are chronically depressed are at greater risk of heart disease, diabetes, osteoporosis, and many other medical problems. Nobody knows exactly why this atrophy occurs. Neurons may die or shrink, or ones that should have been born to replenish the region may not be. Whichever, it does seem linked to a stress hormone called cortisol, because about half of seriously depressed patients secrete too much cortisol.

After meication and reduction in cortisol levels saw their brain chemical return to normal, cell growth and restart and the hippocampus return to its pre-depression size.

This in hippocampal volume loss in depressed humans could possibly be prevented by anti- depressants.