This appears to be a study done from the Depression side as opposed to the Chronic Pain side, but the "new" information seems to be technical. The relationship between CP & Depression has been well-documented for a long time. In many circles it's known as one of the "Vicious Cycles" - some times with other symptoms (e.g. insomnia) thrown in - other times not. See:
http://tinyurl.com/34nro8q
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