Apparent discrepancy between published study of gabapentin treatment and internal company report

摘要

To the Editor: The letter by Dr Mayo-Wilson expresses concern about potential discrepancies between an internal company report1 and the article that we published on the effectiveness of adjunctive gabapentin in bipolar disorder. Discrepancies might result in publication bias, so I would like to provide further details on the study.Ours was an investigator-initiated trial that was originally sponsored by Parke-Davis Spain (which had been bought by Pfizer at the time of publication). The study took a long time to complete and was published in 2006. By that time, gabapentin had become generic and had lost commercial interest. It was published, precisely, to avoid publication bias. Our study found that gabapentin was associated with modest improvements in a rough measure of clinical outcome but had no effects on preventing further episodes. The publication truly reflects the outcome of all the patients who fulfilled the prespecified inclusion criteria, and the interpretation of the results avoids, in my view, any uncritical support for the use of gabapentin as an adjunct to lithium in patients with bipolar disorder.