Since stress has been described as a potential trigger for ME/CFS (422) and cause of symptom flare-ups (423, 424), it is likely that the HPA axis- the neurobiological stress system- may be implicated in ME/CFS (53, 425, 426), as well as abnormalities in growth hormone (GH) secretion and dysfunctional adrenergic metabolism (255). Here, GH1 is linked to myalgic encephalomeyelitis/chronic fatigue syndrome.