The brain is a very interesting organ, especially it's role in the creation and interpretation of emotion.
If you live a life where you face a trauma when you are young and still developing (brain injury, abuse, witnessing a shocking event, etc), then you can spend your entire life knowing only the immature response mechanism that was used instinctively to cope with that trauma. It becomes your only tool, until you can alleviate the depression, and consciously... slowly... learn and develop new ways to observe and react to the world both outside and inside of yourself.
A depressed person is at a disadvantage because their body chemistry is working against them, and their parasympathetic and neurological systems are using routines, that while harmful, are the only ones they know. Those are like muscles, the more they are used and reinforced, the stronger they become. This is why multiple forms of treatment and therapy are required at all times.
As for the exercise anecdotes - of course exercise is a great thing because it causes a lot of specific hormones to be produced in the body that help regulate all kinds of systems the body uses. There is no question that it is an effective tool in regulating physical, mental and emotional health. Here is a
good article that was written by a psychologist who goes to my wife's gym. My wife experiences anxiety herself and has made it part of her mission to make her facility a place where people can share struggles with mental and emotional health, and perhaps be connected with resources that can assist them, because mental health is such a vital part of our well being. Yet the unfortunate thing is that it is not as mainstream to consciously work on and discuss your mental health the same way it is to work an elliptical machine for 60 minutes... but that is what is required. Maintaining mental health is as much a committed and daily practice as is maintaining your physical health, we would do well as a society to become more conscious of mental health as it relates to our selves, our relationships and our organizations so when someone is working on their mental health, it is viewed as normal and good as it is seeing someone run by on a jog, instead of carrying a stigma like they need to be placed in a padded room and given shock therapy. Honestly, look at the consequences of our broad inability to cope with stress, depression, anxiety, conflict... these are tools that we need to be consciously aware of and developing at as early of an age as possible - just my opinion.
Also speaking from experience, people who experience anxiety and use exercise as their
only means of treatment are only one step ahead of where they were than if they did not exercise. What is required for any healthy individual, to create resilience against anxiety and depression is multiple forms of coping. For instance, my friend deals with anxiety, and is on medication to help, but he's never really been able to find a medication that works really well. The ones that do work, sadly make him feel dead to the world, and that's not the solution he wants. Exercise was the one medicine that made him feel right, and he got good at it. So good at it that he ended up making it to the CrossFit Games in 2010. He got injured during that experience, hurt his lower back quite badly, and has not been able to exercise to the degree that made it an effective treatment for him. So for over 4 years he has been struggling to a massive degree in his personal life, trying to be in control of his anxiety, really frustrated and seeing it as his friend is absolutely heart breaking.
So yeah, I agree with you Pete.. exercise is a great tool, but it is only one. Medicine is an effective tool, but can give a boat load of unwanted side effects.. and again, it is only one tool. Therapy is a good tool sometimes, but it needs to be working on the level that meets the capability of the person, and that's hard to achieve because sometimes you need to go "back" to what feels like very childish levels of capability to begin building the habits and routines necessary for healthy and sustainable responses to emotional triggers. It is difficult, illogical and intangible work.. work that requires a great deal of self understanding and mastery of communicative tools.
No wonder it can feel overwhelming to someone who is lost anywhere on the way down.
And guess what? We are all on this journey. Even someone who is "healthy"... they're constantly having to reinforce healthy coping mechanisms and develop new ones as their world changes. Anyone is at risk of stumbling at any time. All it takes is that one moment to meet the trigger that you don't have the coping mechanism for, and the spiral begins.
The good news is that we are capable of being extremely resilient, as individuals and within friendships, professional relationships, families, small communities, and even large communities.. IF it is a focus. I do what I can to make it one for myself and those in my tribe.