The Penicillin Analogy: Efficacy and Evidence, A Response to Brook

Andrew Brook raises a number of interesting points about our article “Grunbaum on Psychoanalysis: Effective Treatment or Placebo?” (1997). In this response we shall address ourselves to a few of his observations.

One of his points rests on a misunderstanding of our discussion of the reason we need more precise diagnosistic categories to test the efficacy of psychoanalytic therapy. We did not intend to make this point in order to distinguish between conditions psychoanalysis was intended to treat, and conditions that psychoanalysis was never intended to treat such as the common cold. Our point was different Suppose a treatment is intended to treat a disorder or a range of disorders. Suppose further that the studies on this treatment were spotty; that is, some studies showed the treatment to be effective, other studies did not confirm this. Does this necessarily mean that the treatment is ineffective?

We argued that in such a case the treatment is not necessarily ineffective. Sometimes a treatment that is designed to be effective against one condition turns out to effective against a subspecies of that condition. But it is not known at the time that the apparently single condition is really several conditions As Goldsmith (1998, 1) points out:

For example, for a number of years, steroids were found to be somewhat effective in the treatment of nephrotic syndrome, but there were nagging doubts, especially when caring for adults, that this therapy might not out perform the absence of any treatment. At a later time, it was discovered that the apparently single condition, i.e., nephrotic syndrome, was a common manifestation of several different conditions, e.g., minimal change nephrotic syndrome, focal segmental glomerulosclerosis,

Page 135

membranous nephropathy, and membranaproliferative glomerulonephritis, each having a different responsiveness to steroid treatment That is, the apparently single condition was in reality several distinct entities, and once the initial understandin