Biological aspects of post-traumatic stress disorder
In 1864 Mitchell, Moorehouse, and Keen’ described the myriad effects of combat in veterans of the American Civil War. These ailments were variously described as soldier’s heart, Da Costa’s syndrome (effort syndrome), and neurasthenia. Interest in the effect of war upon human behavior and mental health was rekindled during World War I, in which a new diagnostic entity, ‘shell shock", was postulated by Mtt . In 1919, Wearn and Sturgis3 used a biological challenge strategy to explore psychophysiological aspects of soldier’s heart. This is an interesting study in that, so far as is known, it represents the first such attempt to explore an anxiety disorder. The authors paid good attention to the scientific method; in a controlled study, they challenged a group of patients with soldier’s heart by means of i.m. administration of 0.5 cc 1:1000 epinephrine. The authors’ original premise was that soldier’s heart represented a variant of hyperthyroidism, and they reasoned that the associated hypermetabolic state could be unmasked by an epinephrine challenge. As it turned out, thyroid tests were normal but the soldier’s heart subjects responded abnormally to epinephrine, with a rise in systolic pressure above 10 mm, increased pulse rate in excess of 10 beats per minute, and precordial pain, nervousness, palpitations, pallor, tremor, flushing, and sweating. The control group of patients without soldier’s heart failed to manifest these abnormal reactions. In addition, the soldier’s heart patient group also received i.m. administration of a placebo, to ensure that these abnormal reactions were not due to the procedure itself. Their response to placebo was found to be different from the response to epinephrine. From this landmark study, the authors concluded that soldiers heart was associated with a psychophysiological instability of the autonomic nervous system. Careful reading of the clinical descriptions in this report suggest that not all patients would be diagnosed as posttraumatic stress disorder (PTSD) by current nomenclature, but they would almost certainly have met criteria for generalized anxiety disorder. Without doubt, however, a number of the patients were experiencing a post-traumatic stress reaction.
