Pharmacological treatment of chronic fatigue syndrome: focusing on the role of antidepressants

Chronic fatigue syndrome (CFS) is characterized by chronic, medically unexplained fatigue associated with effort- and stress-intolerance, widespread pain, and impairment in sleep and concentration. Although this constellation of symptoms is highly prevalent in clinical practice, the pathophysiological mechanisms underlying CFS are poorly understood. Current evidence indicates similarities in symptomatology, and possibly etiology and pathogenesis, between CFS and depression. Additionally, there is significant overlap between CFS and the syndrome of fibromyalgia for which antidepressants have shown consistent efficacy. Data regarding antidepressant treatment of CFS is less copious and less uniformly positive, such that antidepressant use in CFS remains controversial. The current review aims to summarize available data related to antidepressants and other psychotropic agents in CFS to provide a platform for clinicians to make decisions in their treatment of this challenging syndrome. We identified relevant studies through a PubMed literature search with a combination of the following search terms: 'fatigue,' 'depression,' 'antidepressant,' 'etiology' (e.g., 'neurobiology,' 'neurotransmitter,' 'genetic'), 'diagnosis,' and 'treatment' (e.g., 'antidepressant' plus the specific name). In addition, studies were also identified via the reference sections of retrieved articles. The authors thoroughly reviewed major findings from the scanned literatures and eventually synthesized them, providing summary, interpretation, and future directions.