Bipolar disorder as an emerging pathology in the scientific literature: a bibliometric approach.

Background: To carry out a bibliometric study on the scientific publications in relation to bipolar disorder.
Methods: Using the EMBASE and MEDLINE databases, we selected those documents whose title included the descriptors bipolar disorder, bipolar illness, bipolar patient, bipolar mani, bipolar depress, bipolar spectrum, manic-depressive, and rapid cycling. We applied some bibliometric indicators, as Price's Law on the increase of scientific literature, or the participation index (PI) of the different countries. The bibliometric data have also been correlated with some social and health data from the countries that are most prolific in biomedical scientific production, such as number of physicians, total per capita expenditure on health and overall volume of production in the field of psychiatry.
Results: A total of 4270 original documents published between 1980 and 2004 were downloaded, of which 1825 corresponded to aspects related to drug therapy. Our results state fulfilment of Price's Law, with scientific production on bipolar disorder showing exponential growth (correlation coefficient r = 0.947, as against an r = 0.849 after linear adjustment). The drugs most widely studied are lithium (1351 documents), valproate (544), carbamazepine (493), lamotrigine (240), and olanzapine (210). United States is the most productive country (participation index, PI = 44.2), followed by the United Kingdom (14.4), Netherlands (9.1) and France (4.1).
Conclusion: The publications on bipolar disorder and mood stabilizers have undergone exponential growth over the last 25 years, without evidence a saturation point.