Finzi mentions a “very significant omission” in my article:1 that I did not mention the study by Finzi and Wasserman2 that was “the first to show that botulinum toxin A could be used as an antidepressant.” My commentary was meant to discuss 3 recent developments in the treatment of psychiatric disorders, describing the original ideas that led to the development of those treatments, their current status, and the work that needs to be done to establish them as effective treatments. It was not meant to be a comprehensive review, which would not be possible given the word limit for a commentary. The theory that resulted in the test of botulinum toxin for the treatment of depression, the facial feedback theory, predates the case series of Finzi and Wasserman.2 Furthermore, while a case series may support the idea of carrying out a controlled trial, it cannot demonstrate the efficacy of a treatment. That can be done only in adequately designed placebo-controlled trials. If the antidepressant effect of botulinum toxin is ever established, it would be appropriate to cite the Finzi and Wasserman study2 in a comprehensive review of the topic. However, I decided not to mention the case series as it was not relevant to the objectives of the commentary, given the limitations of a case series in demonstrating the efficacy of a treatment, and because it did not contribute to the theoretical rationale for testing the treatment.
Footnotes
Competing interests: None declared.