The crossroads of melatonin: Bibliometric analysis and mapping of global scientific research

Melatonin is a molecule that has attracted a great deal of attention from the scientific community in the last 50 years. The aim of this study is to analyze the scientific production on related to melatonin using bibliometric tools. We performed a search in Web of Science, involving documents published between 1958 and 2019. We used bibliometric indicators to explore documents production, dispersion, distribution, time of duplication and annual growth, as Price's law of scientific literature growth, Lotka's law, the transient index and the Bradford model. We also calculated the participation index of the different countries and institutions. Finally, through bibliometric mapping, we explored the co-occurrence networks for the most frequently used terms in melatonin research. A total of 20,768 documents were retrieved. Scientific production was better adjusted to linear growth (r = 0.9535) than exponential (r = 0.9313). The duplication time of the documents obtained was 14.2 years. The transience index was 62%, which indicates that most of the scientific production is due to very few authors. The signature rate per document was 1.95. Thirty-four journals made up the Bradford core, highlighting Journal of Pineal Research. USA and University of Texas present the highest production. Map network visualization shows the generated term map detailing on clusters of closely related terms. The growth of the scientific literature on melatonin was linear, with a very high rate of transience, which indicates the presence of numerous authors who sporadically publish on this topic. No evidence of a saturation point was observed. In the last 10 years, there has been a relevant increase in documents on melatonin.