I have seen injured workers with horrible pain and do not appear to be depressed at all.
Pain and depression must be considered as often operating independently of each other. In a recent article (Arthritis Rheum 2005;52:1577-1584), it was found that depression) does not affect the processing of pain. This suggests that both pain and depression both need to be treated when they occur together in the same patient.
We used to believe that if someone has both pain and depression, that maybe depression is causing the pain and if you address depression the pain will get better. New findings contradict that long held belief.
There are three aspects of pain perception and response:
a. the sensory dimension of pain, “which localizes where pain is and determines its intensity;”
b. the cognitive dimension, “what people think about pain and how they respond to it;” and
c. the affective dimension, associated with the emotional processing of pain.
Functional MRI showed that depressive symptoms were not associated with neuronal activation in areas of the brain associated with the sensory dimension of pain (primary and secondary somatosensory cortices). On the other hand, depression was associated with activation in regions of the brain involved in processing the affective dimension of pain (the amygdalae and anterior insula).
In many cases depression and pain occur concurrently, but that does not mean they’re the same underlying problem and can be managed in the same way.
The take-home message is that in pain patients you should look for depression and in depressed patients you should look for pain. And if you see the two of them together, you have to address both of them.”