Analysis of the usage and diversity of grey literature in addiction research: a study
Authors: Shrivastava Rishabh , Mahajan Preeti 
Published: April 2020

Purpose
The purpose of this study is twofold. First, the study shall evaluate the extent of usage of grey literature and its different types of addiction research. The second purpose of the research is to analyze the extent of usage of reports such as research reports, survey reports, data reports, etc. As the reports are produced in general by various organizations and can be accessed by not only academicians but also the general public, they play an important role in the dissemination of research to the people. Therefore, the study endeavored to identify the major organizations that are involved in the publishing of research reports in the field of addiction.

Design/methodology/approach
Scopus database was used for the purpose of collecting the data. References in the reference lists of the articles published in 2018 in the journal Psychology of Addictive Behaviors of the American Psychological Association were collected. Scopus indexes the references of the papers in two different categories, namely, indexed in scopus/scopus references and reference lists. They were then categorized as grey literature and non-grey literature. Further, reports were searched manually so that their producers/authors can be found and categorized according to the organizations.

Findings
The study found that grey literature comprises a very small proportion of citations in addiction research (just approximately 5 per cent). This suggests that the improper indexing and bibliographic control of grey literature may be one of the reasons behind the low numbers. Reports comprised the largest proportion of the grey literature cited in addiction research, followed by software documentation, unpublished manuscripts, guidebooks, handbooks, manuals, websites, government publications, etc. The reports of the US Department of Health and Human Services comprised the maximum citations in the reports category because of the reports produced by organizations like Substance Abuse and Mental Health Services Administration (SAMHSA) which comprised 17.59 per cent of the total reports. National Institute of Health (USA) and Centers for Disease Control and Prevention and others. Other than the reports of the organizations of the USA, the reports published by the organizations of Canada, Australia, UK, New Zealand and one European Body were also cited by the articles of the journal.

Practical implications
The research focuses on the use of grey literature in addiction research. The findings of the study indicate very low citations to grey literature in addiction research. This reinforces the need for a separate worldwide information retrieval system for grey literature for researchers to conduct systematic reviews.

Originality/value
Very few studies have been conducted on the use of grey literature and hardly any research focuses on the use of grey literature in addiction research. The study goes one step further and identifies major organizations that are involved in the production of research reports in the field so that their reports can be properly indexed.