I know very little about this topic so I will pose a question. If certain types of depression can be diagnosed in terms of a chemical imbalance in the brain, what can be said about people whose lives consist of a perpetual feeling of pain?
Not physical pain, of course, but mental/emotional/psychological pain that overwhelms them every single day of their lives? Perhaps derived from loneliness, anxiety, frustration, traumatic past experiences, et cetera?
Does this prevalence of pain cause such chemical imbalances that can be diagnosed as depression or is this something separate entirely?
it's a separate thing.
Chemical unbalance mostly causes you to not receive melatonin, endorphine etc. which leads to depression.
Depressions and most anxieties are also caused by our own brains and I mean our subconsciousness or some other undiscovered areas in our brains.
For example many anxieties (for example the one I'm sometimes suffering from) doesn't occur untill I think about it or something related happens that could "trigger" it.
That's why usually intelligent and sensitive people suffer from them - they tend to analyse everything too much.
Also anxieties lead to depression and there are also different depressions classified fe. on their level etc.
Some people want to kill themselves why other are just sad all the time or they don't see any reason to live but they don't think about death etc.
I wouldn't say that we are born with anxieties.
Real anxieties or real depression is something so terrible that I wouldn't wish it to anyone, and fortunately enough most people won't ever suffer from it.
People tend to say "oh I'm so depressed" or "I suffer from an anxiety lately" but it's all bullshit.
The "Real deal" feeling of depression or anxiety as "illness" is uncomparably much more terrible than the feeling when you feel sad after you brake up with your girlfriend or when you have a bad day.
For example picture a situation when you have a heart attack and you know that you will die within few seconds/minutes - that's how people with serious anxieties feel.. during each "attack", everyday.
It's just a hardcore panic within your brain.
Now picture a situation when you get fired, your gf brakes up with you etc. etc. and you see everything really really damn grey at that very moment - that's how a seriously depressed person feels all the time with that difference that you will feel better within few seconds/minutes and your brain will defend from the terrible situation you're in, you will feel slightly better. Trully depressed person won't.
That's why some sad bullshiting of totally healthy people who had a bad day because something stupid happened is really annoying to me.