Bibliographic databases in psychiatry : an overview

Literature searching has been revolutionised by the desktop computer. Today it is almost incon ceivable to be without the tools to efficiently and comprehensively examine the medical literature. However, as this biomÃ©dicaliterature grows ever more vast, researchers and clinicians need to know which of the many biomÃ©dicaland psy chiatric databases will best cover their particular area of interest. No databases can cover every thing. It is necessary to select the most appro priate source of information for the task at hand and for a literature review this will usually entail the use of multiple methods of data collection. In this brief review databases of particular interest to psychiatrists are discussed1.


Embase (Eisevier)
Embase is a smaller biomÃ©dical database of about three million records and there is about a 40% overlap in coverage between it and Mediine.Embase is more up-to-date, has a European slant and is more comprehensive on drug 'Products not supplied for review: Embase CD Neurosciences (Eisevier), Conference Proceedings on CD-ROM (Elsevier).and Geriatric Psychiatry CD (American Psychiatric Press).
literature and alternative therapies.The indexing system employs the Emtree thesaurus of almost 40 000 medical terms.This provides excellent subject index search capabilities which comple ment the databases' thorough coverage of psy chiatric literature.Academic institutions can subscribe to Embase via BIDS (Bath Information and Data Service).Embase Psychiatry is a subset of Embase.This is a ten-year file with over 303 000 citations, most of which contain ab stracts.Overall, Embase Psychiatry is the most comprehensive specialised CD-ROM database of psychiatric literature which is restricted only by its limitation to references published after 1986.

PsycINFO/PsycLIT/ClinPSYC (American Psychological Association)
PsycINFO, derived from Psychological Abstracts, is subdivided into PsycLIT and ClinPSYC.Psyc INFO (from 1967), the parent database, covers conference reports, case studies and book chapters.PsycLIT (from 1974) omits disserta tions, foreign language books or technical re ports.ClinPSYC (from 1980) covers only references with clinical or medical relevance and excludes books and dissertations.Although ClinPSYC starts five years earlier than Embase Psychiatry, they contain roughly the same number of records and both are updated quarterly.There seems little justification for the APA to charge over double the cost of Embase Psychiatry for their product.The indexing system behind PsycINFO is a vocabulary of 4000 terms which is generally superior to Med iine but inferior to Embase Psychiatry.As expected, these products very much emphasize psychological topics and as such are not realistic alternatives to (but may complement) primary psychiatric or general medical databases.

Full text databases
The American Psychiatric Press have compiled a CD-ROM containing the full text of 10 psychia tric journals and 14 major psychiatric textbooks.Ovid's Core BiomÃ©dical Collections (volumes I, II and III) each contain 15 international journals with full text and graphics compiled from 1993 to date.A total of approximately 40 000 articles.One psychiatric journal is included in each volume.In the future Ovid expects to offer a collection devoted to mental health.New from Elsevier is Bio-Psychiatry on CD-ROM.This is a full text version of three journals: Biological Psychiatry, Neuropsychopharmacology and Schi zophrenia Research.At US$195 it is considerably cheaper than a subscription to the journals themselves!Rapid Science produce Current Opinion in Psychiatry on CD-ROM, a full text and graphic database for all review articles from the journal since 1994.Rapid Science also offer a ten year archive of psychiatric abstracts on CD-ROM called Psychiatry Evaluated Mediine.It offers no additional material beyond Mediine, but is an inexpensive alternative for those interested in an overview of psychiatry alone.SilverPlatter have introduced a very similar product known as Physicians' SilverPlatter: Psychiatry.It is sourced from 205 speciality journals over a five-year period and again appears to offer no advantages over Mediine.
A comparison of the CD-ROMs in psychiatry is listed in Table 1 and Figure 1 outlines which psychiatric database to use on CD-ROM.

Current awareness services
One problem with distributed databases is that the latest literature is not included.Current awareness services attempt to offer a solution by circulating regular abstracts of current articles of interest.The Royal Society of Medicine produce a current medical literature series in specialities ranging from 'Allergy' to 'Virology'.The quarterly psychiatric issue is indexed from 78 key journals.The Institute of Scientific Information produce the more substantial Focus On Series, including Focus On: Psychopharmacology which is distributed on diskette monthly and edited by authorities in the field of biological

Conclusions
CD-ROMs enforce an inherent delay between article publication and availability.Publication on-line overcomes this (Ohles & Walton, 1996).Already, several journals reside solely on the internet and literature search facilities are also increasing (Huang & Alessi, 1996).BIDS data bases are never more than a week out of date.
Ovid and SilverPlatter both have web sites on the internet, and these and other sites allow on-line access to several CD-ROMs (Elameer, 1993).At present, the high costs of electronic databases

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Single user cost as of March 1997,costs for Institutions/multiple copies may vary.
75 000 source items included per year.It covers conference proceedings and book chapters as well as journals.The ISI's citation indexes record all cited references in each article, enabling the researcher to search by citation.For anyone interested in biological psychiatry, this is a valuable acquisition.

Table 1 .
Comparison of CD-ROMs in psychiatry