Global information analytics giant Elsevier announced last week that the United States is the world’s top producer of Alzheimer’s research. But while scientists in the US are playing an integral role in the understanding of Alzheimer’s, the content of research globally is shifting.
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The Dutch company’s new report, which coincides with World Alzheimer’s Month, found that US Alzheimer’s research output is more than twice that of next-ranked China, though the US “collaborates less internationally (44.2% in 2018), than compared to other top countries, e.g. 68.8% of Alzheimer’s research in the UK involved international collaboration and 29.4% did in China in the same year,” researchers said.
The collaboration difference could be due to physical proximity, time zones, or language constraints, report writers noted. However, countries whose researchers collaborate tend to have a greater impact: their research is cited, and thereby used, more frequently.
Elsevier is one of the world’s largest providers of scientific, technical and medical information. Senior vice -president of Analytics for Elsevier, Maria De Kleijn-Lloyd, and her team prepared the report — “Alzheimer’s Disease Research Insights: Impacts, Trends, Opportunities” — mainly for research leaders in hospitals and governments worldwide.
In 2013, an international effort was launched at the G8 Dementia Summit in the UK to find a cure for Alzheimer’s disease by 2025, report writers noted, adding that research funding for Alzheimer’s disease has since more than doubled among its biggest funder, the US National Institutes of Health (NIH). And the amount of Alzheimer’s research has increased steadily since 1980 with some 50,614 items published from 2014 to 2018 related to Alzheimer’s disease.
Compared with global research output, Alzheimer’s disease research has grown at the same pace as research overall and has represented 0.35-0.4% of all research done globally between 2012 and 2018. Still, looking at year-over-year growth, “we see that research output for Alzheimer’s disease exceeded the growth seen for all research between 2008 and 2012,” writers reported. “We anticipate that recent increases in funding will translate into increased publications in the near future.”
In preparation for the annual report, analysts at Elsevier look at research patterns including what articles are being published on what topics. “In those patterns, we see an increased interest in behavioral topics,” De Kleijn-Lloyd said in an interview. “There are more articles being written on the behavioral topics.” The new report reflects that focus by scientists on the behavioral aspects of Alzheimer’s, such as prevention and ways to alleviate symptoms throughout the course of the disease. “A lot of research is on continuing to find a cure, but there is increasing emphasis on topics like sleep, exercise and keeping the brain active,” De Kleijn-Lloyd said.
Elsevier’s report writers do find a disparity in the understanding of Alzheimer’s disease versus the actual production of new therapies, however. “What we see is a limited link between basic research focused on finding a cure and [behavioral] research involving humans. In other diseases, we see these areas closer together.”
De Kleijn-Lloyd said data collected by her team showed that basic science—or the understanding in a biochemical way of what is happening in Alzheimer’s disease—and clinical research resulting in a treatment that can be used in human subjects, are not linked. “There is research in protein markers for Alzheimer’s,” she said. “But it does not reach a live environment where testing on humans might be possible. Of course, [research into protein markers] continues within Alzheimer’s research and is the biggest topic within Alzheimer’s research, but it’s not the only topic anymore.”
Scientists in the US are playing an integral role in the understanding of Alzheimer’s, De Kleijn-Lloyd said—especially the link the disease has with sleep, which is one of the fastest growing topics within research. “Harvard University is leading the way, producing the most amount of Alzheimer’s research of any institution around the world,” she said.
According to De Kleijn-Lloyd, among other things, the report reveals the following:
- Sleep and behavioral topics are increasingly more prominent within Alzheimer’s disease research;
- Research on the disease represents 0.35-0.4% of all research done globally in the past 5 years (2013-2018), with 50,614 items published in this period; and
- Alzheimer’s disease is a bigger burden for women, but research focuses on male subjects: 30% of research focused on humans mention men exclusively, while 26% mention women exclusively.
Scientists all over the world are scrambling to find something, anything to help people who are suffering with dementia and its most prevalent form, Alzheimer’s disease. According to the World Health Organization (WHO), some 50 million people have dementia around the globe, with nearly 10 million new cases diagnosed every year. The WHO projects the number of people with dementia will reach 82 million in 2030 and 152 million by 2050. More than 5 million Americans currently have Alzheimer’s disease, and that number is expected to triple by 2050.
Alzheimer’s disease accounts for up to 70% of dementia cases worldwide, placing a major burden on older people. And some 96 new cases were diagnosed per 1,000 people in 2017. “While the incidence of the disease is increasing, this is largely due to longer lifespans,” study authors wrote. “Research output on Alzheimer’s disease exceeded the growth seen for all research between 2008 and 2012; however, this subsequently slowed and has tracked average growth in global research output since 2013. Although the volume of research has been constant, the content is shifting.”
Since the 1990s, the peptide amyloid-β has been a major focus in research related to the Alzheimer’s. But recently research focusing on behavioral topics—such as learning, sleep and gait—for prevention and treatment, offers new strategies for controlling the disease.
Though the US leads the way on research output, when it’s put into the context of each country’s overall research portfolio, the focus on Alzheimer’s disease research is highest in high-income countries, with Sweden, Italy and Spain at the top. “This reflects the high priority this research has taken in countries where lifespan is longer and therefore incidence and burden of Alzheimer’s disease is higher,” study authors wrote.
“Collaboration is prominent across the board, both across countries and sectors. At the institutional level, Sweden’s Karolinska Institutet stands out with 82.4% of its research resulting from international collaboration,” they wrote.
Though many failures have occurred in the ongoing attempt to find a cure or even a treatment for Alzheimer’s and dementia, De Kleijn-Lloyd said there is no indication in the data that researchers are giving up.
What the data does show is increased interest in the behavioral topics, she said. “Articles written on these topics are highly cited,” De Kleijn-Lloyd said. “When you look at the data, they focus on what actually happens in the brain during sleep—they look at the link on what biologically and neurologically happens. There is a link between behavior and what happens in the brain with or without Alzheimer’s.”
In preparation for the report, Elsevier analyzed over 5,000 scientific publications and how many publications come out of what institutions. The following is a list of the top 10 countries based on publication count, according to Elsevier’s research:
1. United States
2. China
3. United Kingdom
4. Germany
5. Italy
6. France
7. Canada
8. Japan
9. Spain
10. Australia
Following are the top 10 institutions based on publication count:
1. Harvard University
2. Institut National de la Santé et de la Recherche Médicale
3. University College London
4. CNRS
5. University of California at San Francisco
6. Karolinska Institutet
7. Department of Veterans Affairs
8. University of Pennsylvania
9. German Center for Neurodegenerative Diseases
10. National Institutes of Health
“Worldwide, the biggest institution in Alzheimer’s research is Harvard University,” De Kleijn-Lloyd said. “A study results in published articles. This is looking at articles in peer-reviewed journals and peer-reviewed conferences. You can count within Alzheimer’s research how many publications come from each institution. Harvard is number one for two reasons. Harvard is the largest contributor to research publications in world, and within Harvard, Alzheimer’s is one of the major topics of research.”
Worldwide, there have been more than 70 million articles in the Scopus database from more than 5,000 scientific publishers, De Kleijn-Lloyd said. Each article has an abstract, at least one author, and is linked to at least one institution. This is how researchers can then evaluate what research is done where.
Analysis of the content of the publications also reveals an opportunity for future research, report writers noted, involving the discrepancies in research related to gender. Researchers found that although Alzheimer’s is a bigger burden on women, research focuses on men. “Although Alzheimer’s disease disproportionately affects women, research using animal models disproportionately features men or male subjects,” they said.
“It used to be completely normal practice, even mandated in some parts of the world, that clinical trials were only done on men,” De Kleijn-Lloyd said. “It takes a long while to change working practices. In the last 20 years, the research community has realized just how much women’s bodies are different than men’s, and that one can’t assume what will work in women will work in men. That’s why it is important that studies are done on women. With Alzheimer’s, we need to look closer at the male and female divide, because women have a higher chance of Alzheimer’s when you correct for age. This is one of the reasons Elsevier recommends more research on women.”
According to De Kleijn-Lloyd, the data in general shows that women get older than men, so you would expect to look at more women. But even if you correct for age, the women still have a higher incidence of Alzheimer’s. “The data doesn’t show why, this is for researchers to investigate,” she said.
