In this Monday, Feb. 22, 2016 file photo, Bill Gates talks to reporters about the 2016 annual letter from the Bill and Melinda Gates Foundation in New York. Photo: Seth Wenig, AP File

Microsoft co-founder and philanthropist Bill Gates has made a personal investment of $100 million to find a cure for Alzheimer’s.

Half of the investment will go directly to the Dementia Discovery Fund (DDF) – a private-public collaboration among major drugmakers like GlaxoSmithKline, Johnson & Johnson and Eli Lilly, as well as the UK government and numerous charities – all with a common goal: discover treatments for Alzheimer’s and dementia.

The remaining $50 million will help fund various start-up companies that are exploring “less mainstream” pathways for Alzheimer’s treatments.

Gates announced his significant contribution in a blog post on Monday. He immersed himself in the field to fully understand the progress that has been made so far, and consulted researchers, academics, funders and industry experts to learn more about the degenerative brain disease. Through this learning process, Gates identified five areas of focus that could “substantially alter the course of Alzheimer’s” if progress and improvements are made.

The five areas include: getting a better understanding of the underlying causes of the disease and its biology; detecting and diagnosing Alzheimer’s earlier; developing more approaches to stopping the disease; making it easier for people to enroll in clinical trials; and using data more efficiently.

Gates, with his background as the co-founder of Microsoft, believes he can be especially helpful with the data-driven aspect. He explained that all the individual data compiled by a pharmaceutical company or research lab should be available in a common form, so that groups of researchers can look for patterns and identify new pathways for treatment.

In his post, Gates explained that he became interested in getting involved with Alzheimer’s research because of both the emotional and economic costs.

According to the Alzheimer’s Association, Americans will spend $259 billion caring for those with Alzheimer’s and other dementias, just in 2017.

But the disease is not only a growing burden on healthcare systems: the less-quantitative toll on patients’ caretakers and families also played a role in Gates’ decision. He noted that, like millions of fellow Americans, Gates has watched numerous family members suffer from the disease.

“My family history isn’t the sole reason behind my interest in Alzheimer’s. But my personal experience has exposed me to how hopeless it feels when you or a loved one gets the disease. We’ve seen scientific innovation turn once-guaranteed killers like HIV into chronic illnesses that can be held in check with medication. I believe we can do the same (or better) with Alzheimer’s,” wrote Gates.

The investment is not part of the Bill and Melinda Gates Foundation, but he did note that when the first Alzheimer’s treatments emerge, the foundation could get involved in expanding access to these treatments in poorer countries.

While Gates understands that potential treatments may still be a decade or more away, he is optimistic that major breakthroughs can happen if progress is made within the five identified pathways.

“With all of the new tools and theories in development, I believe we are at a turning point in Alzheimer’s R&D,” he said.

Currently, dementia (the most common form of Alzheimer’s) affects nearly 50 million people worldwide. That number is expected to grow to more than 131 million by 2050, according to the group Alzheimer’s Disease International. Alzheimer’s is also the only “Top 10” disease in the U.S. without any meaningful treatment options.

“This is a frontier where we can dramatically improve human life. It’s a miracle that people are living so much longer, but longer life expectancies alone are not enough. People should be able to enjoy their later years—and we need a breakthrough in Alzheimer’s to fulfill that. I’m excited to join the fight and can’t wait to see what happens next,” said Gates.