“…(M)any researchers… are coming to believe that psychological factors play a crucial role in perpetuating many physical illnesses, particularly a subset of chronic ailments that defy logic, diagnosis or a cure. It seems that the way you think about your illness can actually affect how sick you get.

These ‘multi-symptom illnesses’ — which include chronic fatigue syndrome, fibromyalgia and potentially others such as Gulf War syndrome, irritable bowel syndrome and the condition known as multiple chemical sensitivity — have provoked intense controversy. Because they have no obvious biological cause, some doctors and researchers dismissed them in the past as hysteria or the ‘yuppie flu.'” (Psychology Today)