ACHE and myalgic encephalomeyelitis/chronic fatigue syndrome: Therefore, we investigated the alterations in stress hormones such as cortisol and dehydroepiandrosterone sulfate (DHEAS) in CFS patients before and after 4-week administration of galantamine hydrobromide, a selective acetylcholinesterase inhibitor, and aimed to investigate whether there are any relationships between the probable hormonal changes and cholinergic treatment.