Psychological stress and fibromyalgia: a review of the evidence suggesting a neuroendocrine link

Abstract

The present review attempts to reconcile the dichotomy that exists in the literature in relation to fibromyalgia, in that it is considered either a somatic response to psychological stress or a distinct organically based syndrome. Specifically, the hypothesis explored is that the link between chronic stress and the subsequent development of fibromyalgia can be explained by one or more abnormalities in neuroendocrine function. There are several such abnormalities recognised that both occur as a result of chronic stress and are observed in fibromyalgia. Whether such abnormalities have an aetiologic role remains uncertain but should be testable by well-designed prospective studies.

Figure 1

Scheme showing the hormonal pathways implicated in stress and fibromyalgia. GHRH, growth hormone releasing hormone; CRH, corticotrophin releasing hormone; GnRH, gonadotrophin releasing hormone; GH, growth hormone; ACTH, adrenocorticotrophic hormone; FSH, follicle-stimulating hormone; LH, luteinising hormone; DHEA, dehydroepiandrosterone.

Figure 2

Scheme showing the pain-modulating pathways in the dorsal horn of the spinal cord. Nociceptive A-delta fibres and nociceptive C fibres cause release of substance P in the dorsal horn. Serotonin released by the dorsolateral inhibitory tracts inhibits the release of substance P.