The goal of this broad, preliminary analysis of ASD research publication data was to examine the development and current state of autism science to inform the strategic planning efforts of the Interagency Autism Coordinating Committee (IACC) and to help various stakeholders gain insight into the possible impacts and implications of ASD research activities and investments. Publications serve as a primary output of research efforts, and an in-depth understanding of autism publication trends can help research funders, policymakers, researchers and other community stakeholders design strategies to maximize progress and cultivate breakthrough research. The data presented in this report can be used to identify potential areas of need as well as opportunities to leverage strengths across funding sources and research communities.

Collectively, the findings presented in this study suggest that autism research is a young but rapidly evolving and growing field. The recent rise in autism research publications has been remarkable, particularly since 1999, when the growth in autism publication rates began to far outpace comparable research literature. Using several parameters related to autism publications, research activity as measured by publication output was found to be expanding across all areas of the IACC Strategic Plan, with strong growth in publication rates in the last decade. The largest proportion of publications were related to the Biology Critical Question area (38% of 2010 autism publications), which encompasses a broad range of basic research focused on clarifying the underlying biological mechanisms that contribute to ASD. Publications that address Treatments and Interventions and Risk Factors had the second and third highest output in 2010 (19% and 17%, respectively). Overall, the Critical Question categories related to more basic research, particularly Biology and Risk Factors, demonstrate more publication activity than the translational categories of Diagnosis and Treatments and Interventions, which supports the hypothesis that autism research is still in a relatively early stage of development, though evolving rapidly. In the future, it will be important to track whether autism research activities shift from a basic science and discovery phase to one that is more translational, with a stronger focus on the development of practical applications in the clinic and in the community, indicating increasing maturity of the field.

Spotlights on the Risk Factors and Treatments and Interventions Critical Question areas, which are of particularly high interest in the autism stakeholder community, revealed important research trends in each group. Within the set of Risk Factors research publications, though Genetic Risk Factor research accounted for a majority of 2010 publications (56%), the number of publications on Environmental Risk Factor research accounted for 39% of 2010 Risk Factor publications and has been increasing at a rate similar to that for Genetic Risk Factors for the past decade. Epigenetic publications accounted for a relatively small share (5%) of autism research publications in 2010, but this emerging area of research has been growing appreciably since 2006. Risk Factor publication trends indicate that Environmental research activity is strong and that major advances in genetics and more recently in the understanding of epigenetics appear to be taken up quickly by the autism risk factor research community. The spotlight on Treatments and Interventions also highlighted emerging areas, showing a recent increase in publications related to Occupational, Physical, and Sensory-Based Therapies as well as Complementary, Dietary, and Alternative Interventions in the last few years. Behavioral interventions accounted for the largest proportion of publications in this Critical Question area (26%), followed by Medical/Pharmacologic treatments (18%), which have grown substantially since 1995. Since 2000, the strongest growth was observed for publications in the Technology-Based Interventions and Supports subcategory, and this trend is likely to continue as broader scientific and technological innovations continue to advance.

Commensurate with rising ASD research publication counts, autism research articles are arguably demonstrating greater research impact, with citation rates increasing between 1980 and 2009. Moreover, the average number of citations that autism publications receive was found to be higher than that of publications in comparable research fields, and the proportion of highly cited autism publications has been generally increasing since 1995. Recognition of autism publications in the scientific community has increased, particularly in the last decade, and mirrors the heightened awareness of autism in the public sphere, lending further support to the idea that the autism research field is growing and increasing in maturity.

Just as the NIH funding for autism has increased substantially in the last 10 to 15 years, results of this analysis indicate that this may be true for global autism funders, as well. While it was beyond the scope of this report to estimate global funding trends for autism, this report examined the publication activity of global funders acknowledged for supporting autism research articles published in 2010. Although autism funding acknowledgment analysis was limited by a low proportion of articles containing funder acknowledgments, the most-acknowledged funders of autism publications still likely represent major contributors to global ASD funding.

More than 700 different funding organizations were acknowledged in 870 autism articles published in 2010, consisting of an international mix of governmental agencies and private organizations. Approximately one-third of publications with funding acknowledgments cited some combination of US government, US private, and international funding support, indicating that the research community is leveraging investments from many funding sources to support research activities. The pattern of research topics supported by different funders – namely US government, US private, and non-US funders – is generally the same, with the strongest emphasis on Biology, Treatments and Interventions, and Risk Factor research for all three funder types.

As mentioned, a major limitation to the comprehensive analysis of research publication output from funders was imposed by the low proportion of funding acknowledgments found in 2010 autism publications (36%). With only approximately one-third of research articles citing funding, estimation of the outputs resulting from funder investments and productivity of global research institutions was significantly constrained. It is probable that many funders of autism research were not acknowledged for their support, making it impossible to ascertain the full scope of the outputs resulting from their investments. In the current era of tightening research budgets in the US and a number of other world economies, it is critical for funding organizations to demonstrate that research investments are resulting in positive outputs and outcomes to justify continued and enhanced research support. Thus, it is critically important for funders, policymakers, research institutions, and scientific publishers to encourage more accurate acknowledgment of funding within the various disciplines of ASD research to ensure sustained support and continued growth of the field.

This analysis also illustrates that autism research is an increasingly global endeavor. US investigators have been and continue to be the most prolific publishers of autism research; however, it is encouraging to see that other countries have substantially augmented their research efforts in recent years. With trends toward many non-US countries such as China, South Korea, India, Japan, Finland, and Germany as well as many other developing countries increasing the percentage of their gross domestic product devoted to research and development efforts, we expect that the autism research outputs of non-US countries will continue to increase.³²

Finally, a defining trend revealed in this analysis is that research efforts are increasingly collaborative, crossing both institutional and national boundaries. In 2010, more than 20% of autism publications listed authors from multiple countries, which was double the proportion observed in 2000 and substantially higher than that seen in 1980, when it was near zero. The trend toward increasing collaboration is not limited to shared efforts between small groups of top-publishing countries. The network of international collaboration is increasingly being shaped by a growing number of country partners. It also appears that multi-institutional and multinational autism research publications are particularly influential, as they tend to be more frequently cited by their research peers.

In conclusion, the trends revealed by this analysis suggest that the young and rapidly growing field of autism research is benefiting from scientific advances in related emerging fields, increasing in impact, and becoming more collaborative and global. The US and the global autism research community should continue to leverage scientific opportunities and public and private investments in autism science. Critical research discoveries are still needed to find solutions to the most pressing medical and social challenges faced by people with autism, their families, and their communities. The in-depth description of the global autism research publications landscape provided in this report can aid the collective efforts of the IACC and broader autism stakeholders to enhance research efforts that can address the urgent need for more effective diagnostics, treatments and interventions, and services to meet the needs of individuals and families affected by autism across the lifespan.