Maybe it's simply too much stress = a type of physical/emotional paralysis of sorts. Sort of an emotional threshold point that is too much for the nervous system. Basically people who are "depressed" are sick just like having a flu. I don't think its caused by a chemistry defect thing in the brain. I think it is simple stress/distress. Isn't this very simple and how did this get sort of turned around into a congenital defect of the brain chemistry.
Interesting that you brought this up. I just read something last week, a series of studies I think, that seemed to "suggest" the same thing at the conclusion. Where it overlaps for me, is that even by restricting calories and being physically active... I seem to add more pounds than lose them. For awhile, I just said, OK I'm 55... this is just natural aging. EXCEPT - that I never had a tendency to gain weight. Sort of like one of those babies that are never chubby & roly-poly... I could stuff my face and never, ever gain an inch or a pound - not even through pregnancy. And I never worked out or was involved in organized sports any more than I was required to be.
I've been interested for awhile in the mind-body connection and experienced first-hand the benefits to my nervous system from tai chi. But I'd never had any interest in diets or their theories. Never applied to me. Once I started reading, I got frustrated pretty quickly - because there's a lot of contradictory ideas, folk myths, quasi-science and even nutritional docs and neuroscientists seemed to cancel every promising idea out. Well, being a long time reader of Prevention I picked up a few things to look at - and even there, I kept seeing different systems and it started me thinking that there are different sets of physical problems; like different metabolism or physical "types". So, I broke down and bought the book on the Hormone Diet -- along with another one on Chinese Medicine. I've using herbs, and learning how... all the way back to Twiggy's time frame... it was just always in my environment. The doctor who wrote the book, kinda confirmed my idea that we are different "types", physically - and it's linked to the effect of these hormones on the brain.
Lupita posted something yesterday about how serotonin and dopamine are linked to whether someone is a pessimist or optimist and there wasn't anything one could do to change this, because it was genetic. The effects of living with N in a primary caregiver is practically speaking, just as deep and intertwined in our cells and brains. But in both situations, there is some science and there are doctors with some experience - using herbs to tweak our hormonal levels. These hormonal levels DO affect the functioning of the brain - and in turn, that level of functioning affects the physical body. This self-perpetuating cycle of existence CAN BE caused by life-long stress: i.e., having to live with a primary caregiver who's PD or N or just plain mentally ill and mean.
Even here - a bunch of us know that if we're flooded with a big anxiety attack or overwhelming helplessness - sometimes, just going for a walk will help lift it. The walk, the sunshine (vitamin D) and fresh air is a positive antidote to temper those old emotion-patterns. Lupita likes to dance; she feels more alive when she's dancing - it's that same chemical stimulus - response at work. But we don't really BELIEVE it's that simple. We can't really convince ourselves; we don't know how it works. And the feelings only change temporarily - according to our perception. But over time, I think there are small gradual (imperceptible) progressions that can become more permanent.
I'm not sure I believe all this, anyway. But, I am trying some things to see what happens. I simply got serious about taking my multivitamin everyday - and added a supplement for thyroid support. Next up, Omega 3s... because according to this system and knowing my own history... I have some inflammation issues that stress my immune system. And then there are a few more - working from biggest problem to the slightest. The book helps one self-identify the issues and can be supported with blood tests, too. But the Docs' idea is that each of us will need a different amount of time to bring those hormones back into balance - you won't take these supplements forever - and the process is slow and gradual, and not everyone needs everything. She walks one through the "trial & error" of seeing what works for you... without putting yourself even further out of whack. And of course, there is an exercise/activity component.
So, star... once Western medicine decided that the mind/emotions and body were separate things... they "forgot" the basic understanding that our emotions can affect our body... and vice versa. I think like you - that lifelong stress isn't the same thing as a brain defect or PD. And I suspect - I'm still learning what works for me - that what we need is simply a gentle shove in the right direction to get those hormone levels back in balance. My weight is still bouncing around - lose 2.5 lbs one day, gain it all back the next - but what I've noticed is that emotionally I FEEL better. Didn't really expect that. I feel like I have more energy, I want to do things that are more active, etc.
I'm still playing around with this... it seemed way too simple; the old "here, take this pill and magically all will be well". I'm still skeptical about that. But if I can start being more physically active, without pooping out right after starting... well, that's another microstep to the ultimate goal. And I can live with a side effect that makes me feel emotionally a bit clearer, calmer, more balanced at the same time, too!
(Disclaimer: one could view this really cynically as just another form of placebo effect. Having a really cynical side to me... helps me kinda keep those expectations in check. She's been showing up a lot lately (ironically) even as I start to feel "better".)