Biological markers in chronic pain syndromes

While acute pain may promote survival and restitution, chronic pain is usually destructive. In acute pain, the clinical symptoms and signs are similar to those seen in anxiety states while the symptoms and signs seen in chronic pain are similar to those seen in depressive syndromes. As there are so many clinical similarities between chronic pain syndromes and depressive syndromes, it has been suggested that the two syndromes share a common pathogenetic mechanism, that the chronic pain syndrome is a masked depression, that the chronic pain syndrome is one syndrome in a spectrum of depressive disorders (depressive spectrum disease) or that the chronic pain syndrome is a variant of depressive disease. In some chronic pain syndromes, there is no organic pathology or pathophysiological mechanism that can account for the pain. These syndromes are called idiopathic pain syndromes and are operationally defined. In idiopathic pain syndromes as well as in depressive disorders, there is an increased frequency of aff...