Supplementary Material for: A Bibliometric Analysis of European versus USA Research in the Field of Addiction. Research on Alcohol, Narcotics, Prescription Drug Abuse, Tobacco and Steroids 2001-2011

<b><i>Background:</i></b> To compare the publication and citation rate within the areas of drug abuse and dependence research in Europe with that in the USA. <b><i>Methods:</i></b> This is a bibliometric study using the <i>Thomson Reuters Web of Knowledge</i> as data source, 40 key words were used as search terms, but certain scientific publications not concerning the issue were excluded. Scientific publications from Denmark, England, Finland, France, Germany, Italy, the Netherlands, Norway, Spain, Sweden, and the USA were studied. The number of publications in each country and in each year in addition to the citation indices for these publications was retrieved. <b><i>Results:</i></b> Approximately two thirds of the publications came from the USA. Both in absolute and relative figures, Europe lagged behind. The trend over the last decade was a greater gap between the amount of research performed in Europe versus the USA. There were thematic differences. Smaller European countries had a greater relative publication rate. The citations were relatively evenly distributed. <b><i>Conclusions:</i></b> It has been claimed that 85% of the world's research within the field of drug abuse and dependence is carried out in the USA. This study challenges this figure, but European research within this field is lagging behind.**背景**：本研究旨在对比欧洲与美国在药物滥用与依赖（drug abuse and dependence）研究领域的论文发表量及引用率。 **方法**：本研究为文献计量学研究（bibliometric study），以汤森路透Web of Knowledge（Thomson Reuters Web of Knowledge）作为数据源，采用40个关键词作为检索词，并排除了与研究主题无关的学术文献。研究纳入了来自丹麦、英格兰、芬兰、法国、德国、意大利、荷兰、挪威、西班牙、瑞典及美国的学术文献，提取了各国每年的论文发表数量与对应论文的引用指标。 **结果**：约三分之二的论文来自美国。无论从绝对数量还是相对占比来看，欧洲的研究产出均落后于美国。近十年间，欧美研究产出的差距呈现不断拉大的趋势。同时存在主题层面的差异：欧洲小型国家的相对论文发表率更高。论文引用分布相对均匀。 **结论**：此前有观点称，全球范围内85%的药物滥用与依赖研究均由美国开展。本研究对这一数据提出了质疑，但同时证实欧洲在该领域的研究仍处于落后状态。