'In the 1980s, the entire medical profession was in outright denial that chronic fatigue existed. The consensus was that clinical depression was associated with tiredness, which was a result of apathy. Was the patient truly too tired to get out of bed, or was he just too lazy to exercise?
It wasn’t too long before another complaint joined the growing list of symptoms associated with chronic fatigue. Those with chronic fatigue syndrome (CFS), not recognized as a medical condition until the late 1980s, had trouble sleeping. They also had reduced daytime alertness, called “brain fog.”'