A 2005 systematic review which looked at the course of<unk>  without systematic biological or psychological interventions found that "the median full recovery rate was 5% (range 0–31%) and the median proportion of patients who improved during follow-up was 39.5% (range 8–63%). Return to work at follow-up ranged from 8 to 30% in the three studies that considered this outcome. ... In five studies, a worsening of symptoms during the period of follow-up was reported in between 5 and 20% of patients." A good outcome was associated with not attributing illness to a physical cause, and having a sense of control over symptoms. Other factors were occasionally, but not consistently, related to outcome, including age at onset, a longer duration of follow-up, and less<unk>  severity at baseline. The review concludes that "irrespective of the biology of<unk> , patients’ beliefs and attributions about the illness are intricately linked with the clinical presentation, the type of help sought and prognosis" Another review found that children have a better prognosis than adults, with 54–94% having recovered by follow-up compared to less than 10% of adults returning to pre-illness levels of functioning.
Chronic fatigue syndrome
Hypothyroidism
Cancer-related fatigue
Idiopathic chronic fatigue
Da Costa's syndrome  Da Costa's syndrome  1
Exercise addiction
Medication phobia
Generalized anxiety disorder