Alzheimer’s disease is our most expensive illness, costing an estimated $236 billion last year, including nearly 1 in every 5 dollars spent through Medicare.

It is also one of our most devastating, ripping from seniors the precious memories of their long lives, and taking from friends and family members the person they knew. For all involved, it makes the final months or years before death excruciatingly sad and painful.

File photo/Herb Swanson Though medications can help delay its onset, Alzheimer's is the only disease among the top 10 causes of death that we are not able to truly treat, prevent or cure.

The only way to lessen that pain and enormous cost – estimated to rise to $735 billion in Medicare and Medicaid expenditures alone by 2050, overwhelming those programs – is through research, and while the United States has made great strides in this area, there still is more to do.

The clock is ticking, however. Roughly 5.2 million Americans now have Alzheimer’s; that number is expected to rise to 14 million by 2050. And that doesn’t include the millions of people caring for someone with the disease, often sacrificing their own health and well-being.

The options for treatment now are scarce. While medications can help delay the onset of Alzheimer’s in some patients, it is the only disease among the top 10 causes of death that we are not able to truly treat, prevent or cure.

To make that a thing of the past, advocates say the United States must dedicate $2 billion a year to Alzheimer’s research. We are halfway there, thanks to efforts by advocates and lawmakers such as Maine Sen. Susan Collins, the Senate co-chairwoman of the Congressional Task Force on Alzheimer’s Disease, a group she helped organize more than a decade ago.

In 2010, Collins introduced the National Alzheimer’s Project Act, which set up a national plan to solve Alzheimer’s, with the goal of treating and preventing the disease by 2025. President Obama signed it into law in 2011.

Last year, an additional $350 million was added to federal funding for Alzheimer’s research, bring the total to $991 million.

There has also been legislation to help caregivers, including the Collins-sponsored RAISE Family Caregivers Act, which passed the Senate unaminously and awaits further action. It would coordinate existing resources to help family caregivers dealing with all types of health issues.

The Alzheimer’s Caregiver Support Act, also introduced by Collins, would provide grants to organizations that train and support caregivers for Alzheimer’s patients.

That is a key part of the fight against Alzheimer’s. For every person with the disease, there are more who are by their side, often at great cost to their own finances and mental health. Supporting these caregivers not only lessens the toll on them, but also keeps patients in their homes longer, far reducing the cost of care.

These initiatives have enjoyed broad, bipartisan support. That must continue – the cost of stopping now is just too high.