Recent neuroendocrine studies suggest that patients with chronic fatigue syndrome may have increased brain serotonin activity.1 2 This could be relevant to the pathophysiology of chronic fatigue syndrome because serotonin pathways have a role in mediating central fatigue.3 Currently, however, the existence of abnormal serotonin neuroendocrine function in patients with chronic fatigue syndrome is controversial because of contradictory findings from samples of heterogeneous patients 4 5 and the use of serotonin probes such as buspirone, which are of doubtful pharmacological specificity.1 We aimed to measure the increase in plasma prolactin after administration of the selective serotonin releasing agent d-fenfluramine in men rigorously diagnosed as having the chronic fatigue syndrome and carefully matched healthy controls.
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Source: Sharpe M, Hawton K, Clements A, Cowen PJ. Increased brain serotonin function in men with chronic fatigue syndrome. BMJ. 1997 Jul 19;315(7101):164-5. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2127129/