Investigating CAM

I applaud Lloyd Oppel's objection to wasting money testing highly implausible therapies, but it seems to me that he is missing the bigger picture. Important new ideas often seem implausible at their inception. The goal of therapeutic research should be to generate important, novel (and hence, at the outset, implausible) ideas, find out which of them may actually be correct, and then gather definitive evidence one way or the other. My article1 outlined a practical, low-cost strategy for determining which complementary and alternative medicine (CAM) approaches are plausible enough to justify a thorough and fair evaluation.

Government and nongovernment funding agencies have taken the position that CAM merits evaluation. Furthermore, CAM may infuse important new ideas into medicine at a time when much of our mainstream therapeutic research agenda serves the pharmaceutical industry.

Glucosamine sulfate is a safe, inexpensive and potentially useful therapy for osteoarthritis2 that is especially interesting because it is clinically plausible but biologically implausible. We recently proposed that sulfate, rather than glucosamine, could mediate its beneficial effects.3

Oppel cites 2 negative RCTs of St. John's wort in depression. The first was restricted to patients with severe, chronic depression, and its authors suggested that people with milder and less chronic disease might have done better.4 In the second trial, also restricted to patients with major depression, St. John's wort fared no worse than the established treatment, sertraline.5 One might conclude that severely depressed patients — especially those referred to specialty units and in whom standard antidepressants fail — are unlikely to respond to St. John's wort.

Oppel misunderstands my point about the role of plausibility in setting standards of evidence. If is often said that there is no difference between CAM and conventional therapies; rather, there are only therapies that either work or don't work. The reality is that scientifically oriented physicians accept a lower standard of evidence for adopting a therapy they consider scientifically plausible.

L. John Hoffer Sir Mortimer B. Davis – Jewish General Hospital Montréal, Que.