A total of 120 patients subjected to planned operations for diseases of thoracic and abdominal organs and main vessels were examined for an objective evaluation of the postoperative pain syndrome. The psychological status of patients and its relationship with the painful syndrome and narcotic doses needed for pain arrest were studied. In the control (100 pts) the initial depression and postoperative pain were in direct correlation. Tetracycline antidepressant lerivone was used to confirm the results. Depression and the severity of postoperative pain decreased significantly in 20 patients.