ABSTRACT
There is a public belief that strong scientific evidence exists to support the proposition that depressed mood is associated with immune impairment. Eighty-seven per cent reported that depression resulted in medically significant immune dysfunction, although only 21 % were able to offer a plausible pathophysiology as to how this might occur. Although a number of research reports have suggested an association between depressive disorders and impaired cell-mediated immunity (CMI), especially in older more severely depressed patients, the results have been inconsistent. Non-melancholic patients were not impaired at baseline and, on the whole, did not receive pharmacotherapy. They have also experienced less change in their depressive symptoms over the course of the study. It would appear that effective pharmacotherapy for melancholic depressive disorders results in normalization of CMI as assessed by both delayed-type hypersensitivity skin testing and phytohaemagglutinin mitogen stimulation assay.
