WASHINGTON -- Effective treatments for Alzheimer's by 2025? That's the target the government is eyeing as it develops a national strategy to tackle what could become the defining disease of a rapidly aging population.

It's an ambitious goal, and on Tuesday, advisers to the government stressed that millions of families need better help now to care for loved ones. "What's really important here is a comprehensive plan that deals with the needs of people who already have the disease," said Alzheimer's Association President Harry Johns, one of the advisers.

Families approach the advisory committee "reminding us of the enormity of our task," said panel Chairman Dr. Ron Petersen, an Alzheimer's specialist at the Mayo Clinic.

The White House is developing the first National Alzheimer's Plan to address the medical and social problems of dementia -- not just better treatments but better day-to-day care for dementia patients and their overwhelmed caregivers.

The plan is being written, with the panel's input. But a draft of its overall goals sets 2025 as a target date to have effective treatments and ways to delay if not prevent the illness.

Some advisory members said that's not aggressive enough, and 2020 would be a better target date. "We think the difference of five years is incredibly meaningful," said Dr. Jennifer Manly of Columbia University.

An estimated 5.4 million Americans already have Alzheimer's or similar dementias -- and how to help their families cope with day-to-day care is a priority, the advisory committee made clear Tuesday.

By 2050, 13 million to 16 million Americans are projected to have Alzheimer's, costing $1 trillion in medical and nursing home expenditures. That doesn't count the billions of dollars in unpaid care provided by relatives and friends.

Today's treatments temporarily ease dementia symptoms, and work to find better ones has been frustratingly slow. Scientists know Alzheimer's brews for years before symptoms appear, and they're hunting ways to stall it, maybe long enough that potential sufferers will die of something else first. But it's still early stage work.