Valid measure of antidepressant efficacy in primary care is needed

EDITOR—The study by Philipp et al comparing hypericum extract and imipramine or placebo seems to show that hypericum is as effective at treating moderate depression as imipramine.1 This impression is strengthened by the design of the study, which is double blind, randomised, and placebo controlled, using a widely used medication as a comparator and using globally accepted depression scales including the Hamilton depression score. Linde and Berner, however, in the accompanying commentary question the efficacy of hypericum because of its use in comparatively large doses and its comparison with low doses of standard antidepressants.1 They believe that these, together with the effect of unblinding on outcome, should be taken into account in the analysis of the results. The basis of this criticism is the lack of universal consensus on how the effects of antidepressant drugs should be measured in primary care. Difficulty arises because lower doses are often used to treat patients who may be less depressed than those seen in secondary care, and the treatments themselves may be more important as an adjunct to the interaction between doctor and patient than as a therapeutic intervention alone. Patients, too, may prefer to use treatment options that they see as more natural, including hypericum, and doctors are beginning to accept the importance of supporting patients' choices.2 Linde and Berne do not consider that most general practitioners use 20 mg of fluoxetine when treating depressed patients, and few are prepared to increase the dose beyond this level. This reluctance is less likely to be present with a treatment that is seen as part of alternative medicine and less likely to produce side effects.

Further, in practice both patients and doctors know which medication has been prescribed, and the pragmatic nature of the trial conducted by Philipp et al reflects …