Biochemical clues to a fibromyalgia-depression link: imipramine binding in patients with fibromyalgia or depression and in healthy controls.

Both fibromyalgia and depression may be related to disturbed serotonin metabolism, and an association between the 2 disorders has been postulated. We measured 3H-imipramine binding (IB), a biochemical indicator of serotonin uptake, pretreatment, in 10 nondepressed women with fibromyalgia, 14 subjects with major depression, and 10 volunteer controls. Our objective was to determine if IB in the 2 patient groups differed and in the same direction from the control values. Compared with depressed women, IB was significantly lower both in the women with fibromyalgia and in the men with depression. However, no women with fibromyalgia or men with depression had IB levels that were significantly different from control women and men. There was a trend for higher IB levels in depressed compared to control women.