Body and mind, who bosses whom?

When people get body pain without "diagnosable causes", it is commonly believed that the causes are mental. However, I like to challenge this "belief".
I have met so many people who are suffer depression, anxiety or other mental illness but still physically very strong. And on the other hand, I seldom met anyone who are always cheerful when they are in miserable physical conditions. Then people get sick, they just want to "stay in closet", because they do not want to people to see them so sick, because they know they do not have that "positive spirit" to be with others. As a long term CFS sufferer, my experience told me: when I am physically comfortable, I am always (not 100 % of course) in good spirits; but if I am in bad physical condition, I would just be haunted by all those negative thoughts and feelings.
I am not saying that mental strength does not have any power over physical condition, but I do personally believe, that physical health has STRONGER impact on our mental health.
I am not a medical doctor. my words are completely based my own experiences and my own study. So I sincerely welcome any suggestions and criticism.