In general I think we humans have a real need for 'diffinative' (sp?)answers to everything, so if we can't find a physical answer, the problem must then be psychological.
Isn't it kinda like the chicken and the egg? I know pain causes me to be depressed and unhappy, yet being depressed and unhappy also causes me pain.
I know for me, that the pain from all my 'stupid stuff' (back, feet,etc.) causes my 'head', not the other way around. However I found a web site the other day (Invisable illnesses and other disabilities) that had a good article on how our minds can make the pain worse, and a some of what they said was true for me.
Probably the real truth is, there is no mind and/or body, there is just mindbody (no typo) which is one thing, completelyintergrated, and when we have pain, its pain.
Pain is a response to negative stimuli, right? So whether that stimuli is death of a loved one or an injured body part our mindbody is going to react with pain that can be expressed any number of ways.
What needs to happen is we all need to stop putting value judgements on ourselves and others about pain and reaction to pain.
Pain perceived by others to be 'in the mind' also relieves them from having to deal in any way with another persons pain (dealing which can be hard to do) , because mostly our society has a value judgement that pain in the mind is not real or valid.
Goodness, I think I've philosophized(my son calls it sillyphosophizing)enough, sorry this is so long.