Thirty years of scientific research on second-generation antipsychotic drugs in Japan: A bibliometric analysis

Aims: Research on second-generation antipsychotic drugs (SGAs) has experienced great development in last decades. We did a bibliometric study on the scientific publications on SGAs in Japan. Methods: With the EMBASE and MEDLINE databases, we chose papers published from Japan with SGA descriptors. Price’s law and Bradford’s law has been used as bibliometric indicators for quantitating production and dispersion, respectively, of published papers on SGAs. We also calculated the participation index of different countries, and correlated those bibliometric data with some social and health data from Japan (such as total per capita expenditure on health and gross domestic expenditure on research and development). Results: A sum of 669 original documents were published from Japan from 1982 to 2011. Those results fulfilled Price’s law, with scientific production on SGAs showing exponential growth (correlation coefficient r = 0.9261, as against an r = 0.8709 after linear adjustment). The most studied SGAs in Japan were risperidone (n = 192), aripiprazole (n = 109), and olanzapine (n = 106). Division of documents into Bradford zones yielded a nucleus occupied exclusively by the Progress in Neuro-Psychopharmacology and Biological Psychiatry (49 articles). Those publications were in 157 different journals. Seven of the first 10 frequently used journals had an impact factor of being greater than 3. Conclusions: The SGA publications in Japan have been through exponential growth over the studied period, without evidence of reaching a saturation point.