Schizophrenia in Medline 1950-2006: a bibliometric investigation.

The aim was to perform a bibliometric study, and compare the quantity of publications on schizophrenia with the total medical literature in Medline during 57 years, 1950-2006. The annual additions of literature to Medline are continually increasing and form the Medline growth curve. Comparisons of the number of publications on schizophrenia, or any other disease, to this curve, may be used to estimate the research activity. Methods for the identification of relevant references to papers on schizophrenia were evaluated and three different samples were operationally defined, retrieved and counted. During 1950-2006, 16.28 million references were added to Medline. Nearly 68000, 0.42%, references were related to schizophrenia. The percentage of papers on schizophrenia among the psychiatric literature decreased from 5.2 to 2.6%. The present study indicates that the number of references on schizophrenia in Medline has followed the general increase of medical publications. This pattern differs compared to some other research fields such as dementia, HIV, and peptic ulcer. Samples of references on schizophrenia may be retrieved in Medline by operational definitions of search methods. The quantity of schizophrenia research during 57 years has kept pace with the total medical literature. One interpretation of the results is that more resources are needed to enhance research activities on schizophrenia.