A study of 3,035 people in the UK followed them for 43 years of their life and assessed them for chronic fatigue syndrome/ME (CFS/ME) at 53 years of age. 34 (1.1%) of the participants reported a diagnosis of CFS/ME at 53. CFS/ME was more common among women and those who had had mental-health problems between the ages of 15 and 36 were 2.65 times more likely to develop CFS/ME later. Increased levels of psychiatric illness - in particular depression and anxiety - were present prior to the occurence of fatigue symptoms. The more severe people's mental health problems were the more likely they were to develop CFS/ME.
Harvey, S.B. ... [et al] - The relationship between prior psychiatric disorder and chronic fatigue: evidence from a national birth cohort study Psychological Medicine July 2008, 38(7), 933-940