The golden anniversary of Melzack and Wall’s gate control theory of pain: Celebrating 50 years of pain research and management

N ovember 2015 marks the 50th anniversary of the 1965 Science publication " Pain Mechanisms: A New Theory " by Ronald Melzack and Patrick D Wall (1), in which the authors introduced the gate control theory of pain that has since revolutionized our understanding of pain mechanisms and management. The brilliance, creativity and critical thought that went into the formulation and explication of the gate control theory of pain can best be appreciated by reading the original article. Fifty years later, having become part of our scientific history and accepted as common knowledge, the essence of the theory is often conveyed by the familiar diagram in Figure 1. In 1982, the article was recognized as a Citation Classic in Eugene Garfield's weekly publication Current Contents. Citation Classic commentaries were introduced by Garfield to provide the scientific community with " a kind of living history " illustrating the " human side of science " (2). The Citation Classic commentary by Melzack and Wall (3) was a one-page synopsis that included an abstract describing the gate control theory and the authors' reflections on the article's importance and popularity, its ongoing scientific relevance (17 years after publication) and the transformation in treatment it brought about. Because it is as relevant today as it was in 1982, we have reproduced it as Figure 2. Two years later, Garfield (4) highlighted the publication's unusual pattern of citations, noting " the resistance of the research community to new theories, particularly when they are at odds with established dogma ". He pointed out that it had taken 12 years from the time of publication, for the article to reach its peak number of yearly citations of 112 in 1977, for a total of 1027 citations in the 19-year period from 1965 to 1983. The initial resistance (3,4) was gradually overcome by acceptance, as an increasing body of scientific findings supported the concept of a spinal gating mechanism. Remarkably, as we approach the 50th anniversary of its publication, the article's citation rate has continued to climb, reaching an all-time yearly high of 525 (in 2013, measured by Google Scholar [Google Inc, USA]) or 195 (in 2011, measured by the ISI Web of Science [Thomson Reuters, USA]) for a cumulative citation count as of 2014 of >8800 (Google Scholar) or >4500 (ISI Web of Science) (Figure 3). As noted by Melzack and Wall (3) (Figure 2), the acceptance and …