Differences in opinion in regard to the effectiveness of antidepressant drugs are due partly to a lack of knowledge of how they work. The author and his colleagues studied 235 patients being treated with various antidepressants and on the basis of the patients' neurovegetative responses to the drugs (particularly the "side effect" of postural hypotension) were able to recognize reactions which served as guides to drug activity, correct dosage, prognosis, and treatment.Abstract Teaser