A hormone imbalance may cause chronic fatigue syndrome, a study suggests. Researchers in Germany have found that a hormone called ACTH does not work properly in people with the condition. I read about this here: (Edited by Moderator to Remove URL) Apparently the study is published in the journal Psychosomatic Medicine, although I have been unable to find it. I must say I have thought for a long time that my problems may be in some way hormonal, particularly as my fatigue is worse first thing in the morning. Does anyone know anymore about this ?