Medical professionals are much less likely to tell their patients of a diagnosis of Alzheimer’s disease than diagnoses of other chronic or incurable diseases such as cancer, often because of a reluctance to inflict emotional distress, a nonprofit’s annual report has found.

The Alzheimer’s Association -- in its annual look at trends, financial costs and current research into the dementia-causing illness -- said Tuesday that less than half the people who have Alzheimer’s reported being told they had the dementia-causing disease.

This was not because the disease, which destroys people’s memories and abilities to learn, had caused them to forget. The report’s analytical methodology, comparing Medicare records with surveys of both beneficiaries and caregivers, found that doctors and other health care providers give people their diagnosis only about 45 percent of the time. By contrast, the disclosure rate is 93 percent for diagnoses of cancers that affect the breast, colon, rectum, lung or prostate.

A common reason for failure to disclose a diagnosis of Alzheimer’s was the perceived “stigma” of the disease and the reluctance to create additional emotional stress in a patient with a brain disease that progressive, incurable and ultimately fatal, the report says.

“I think part of it has to do with, back in the day, if someone was given the diagnosis of Alzheimer’s disease, it was the social kiss of death, because the impression was, there was nothing to do,” said Pierre Tariot, geriatric psychiatrist and director of Banner Alzheimer’s Institute. “And people are terribly afraid of a disease that robs you of your identity. They tend to look away.”

Tariot also said the lower disclosure rate may reflect the fact that primary care physicians – who must often manage large numbers of patients to stay financially afloat in today’s medical offices-- may simply not have the training or the time to offer a diagnosis.

“Primary care doctors have very, very limited time to spend with patients. And to assess someone with brain failure, you need a substantial bit of time,” Tariot said.

The reluctance to disclose comes despite virtual consensus among the profession that a patient is entitled to know. Yet, the failure to provide the diagnosis leaves patients and their families in the dark, said Beth Kallmyer, vice president of constituent services at the Alzheimer’s Association. She said she has taken calls from family members who were startled to learn that their loved one had Alzheimer’s, even after the person had been taking common medications, such as Aricept, to slow the disease’s progress.

“But you know what? You cause emotional distress giving a diagnosis of pancreatic cancer,” Kallmyer said. “People need to know early.”

Ironically, people in the later stages of the neurodegenerative disease report higher rates of disclosure.

There are several negative consequences to not telling a person that he or she has Alzheimer’s disease, the report says. Families are less able to make financial plans. They have less time to set up a team of caregivers. And it robs the person of his or her dignity and autonomy, the report says.

“Patients have a right to know,” Keith N. Fargo, director of scientific programs and outreach at the Alzheimer’s Association.

But the report also notes that Alzheimer’s is where cancer was decades ago in the public’s perception, when doctors were reluctant to tell their patients that they had been diagnosed with “the Big C” because the disease then seen as incurable. A 1961 survey cited by the report found that nearly nine of 10 doctors made it a policy not to tell their patients they had cancer, often because they thought the patient would lose hope.

In addition to its special report on disclosure, the 88-page Alzheimer’s Association 2015 Facts and Figures report says that an estimated 5.3 million people are living with Alzheimer’s disease, a slight increase over 5.2 million in the estimate from last year’s annual report. The increase represents a shift in demographics toward an aging society, particularly as Baby Boomers grow older.

The 2015 total includes 5.1 million people who are 65 and older and 200,000 who have early-onset Alzheimer’s. Two-thirds of those with the disease are women. The lifetime risk for developing Alzheimer’s at age 65 is one in six for men and one in 11 for women.

The report says about 454,000 new cases of Alzheimer’s were diagnosed in 2010. That number will rise to an estimated 615,000 by 2030, the report says.

The report also contains information on the financial impact of the disease, particularly on the army of unpaid family caregivers who step up to help loved ones with Alzheimer’s. The report cites estimates that 85 percent of unpaid help given to older adults is from family members, whose hidden financial toll in 2014 was about $218 billion, or about 46 percent of Walmart’s net sales in 2013. The direct costs of Alzheimer’s disease and other dementias – medical, hospice and long-term care – will amount to an estimated $226 billion in 2015, nearly 70 percent of which will be borne by Medicaid and Medicare.