Definitions

Functional somatic syndromes are physical illnesses without an organic disease explanation and devoid of demonstrable structural lesion or established biochemical change (Lipkin, 1969; Smith, 1991; Sharpe et al., 1995). Alternative modern descriptors are somatoform disorders and medically unexplained symptoms; other terms which implied occult disease (hysteria), imagined illness ((hypochondriasis), or psychogenesis (psychosomatic syndrome, somatization and abnormal illness behavior) are only rarely used (Sharpe et al., 1995).

The term functional is often misinterpreted to mean that the illness is not very significant, that the suffering is not real, that the treatment will be difficult, time-consuming and likely to fail, and that the patients are unhappy and dull (Lipkin, 1969). In contrast to these misperceptions stands a vast body of recent research that has accepted the reality of functional disorders and has accorded them equal status as targets for serious scientific inquiry into their multiple biological dimensions. A search of the literature published from 1990 to 1996 identified nine syndromes which were intensely studied by numerous and prolific researchers; there were 1051 publications on chronic fatigue syndrome, 728 on fibromyalgia, 656 on irritable bowel syndrome, 609 on premenstrual syndrome, 598 on temporomandibular pain and dysfunction syndrome, 263 on interstitial cystitis, 133 on atypical (noncardiac) chest pain, 112 on multiple chemical sensitivities and 48 on repetitive strain injury. The analysis of the yearly scientific output indicated a steady rate of publications, undoubtedly reflecting continuous interest and the availability of funding.