To the Editor: Lein et al, responding to Cameron's concern that they had not controlled for placebo effect, seem to miss the point ( Physical Therapy , December 1989, Letters to the Editor, pages 1118–1120). Lein et al say they “designed [their] study1 to advance another step,” based on “accepting the findings” of two studies2,3 in which, by their account, “the placebo… was not applied with strong suggestion.” Yet they cite these studies as proof that “placebo [does] not increase experimental pain threshold.” Of course, it is the stronger suggestion (and subject expectation) accompanying treatment that must be eliminated in order to distinguish between placebo and other physiological responses. According to Melzack and Wall,4 only a double-blind study is a valid test of the strength of placebo response.… [ ARTICLE][1] [1]: /lookup/volpage/69/1118?iss=12