Darren McGill and Samantha McSwain-Stith are seen in a scene from the stage production “Forget Me Not.” (Pamela Green)

On a radiant fall day, more than 100 people filed into a gloomy auditorium in Boston to see a play about an even gloomier subject: Alzheimer’s disease and how the progressive, brain-killing condition shakes up an African American family.

“I forget things,” the father onstage says angrily while he and his loved ones remain in denial about his descent into dementia. “I’m sick of people asking me how I’m doing.”

The play, “Forget Me Not,” is part of a larger, D.C.-based project designed to reach a community at risk and encourage participation in research.

Studies show that older African Americans are almost twice as likely as whites to develop Alzheimer’s disease for genetic, biological and socioeconomic reasons. Diet and even the stress of experiencing racism can be factors.

Yet relatively few African Americans want to talk about Alzheimer’s, which is the leading cause of dementia. For historical reasons, even fewer want to participate in clinical research trials that could deliver benefits to themselves and future generations.

Garrett Davis, director of “Forget Me Not,” and Stephanie Monroe, director of African Americans Against Alzheimer’s, collaborated on the stage production. (Pamela Green)

“You just don’t hear about Alzheimer’s in the black community. There’s some stigma,” said Stephanie Monroe, associate director of the African American network at the D.C.-based nonprofit USAgainstAlzheimer’s, the event’s organizer. The organization was founded in 2010 by George Vradenburg, AOL’s former chief counsel, and his wife, Trish, a writer and former journalist.

The effort to engage African Americans on Alzheimer’s comes as the U.S. population ages and becomes more diverse. More than 5 million Americans are living with Alzheimer’s, a number expected to more than triple by 2050, according to the Alzheimer’s Association. In the Washington area, the number of people 65 or older with Alzheimer’s is expected to grow by nearly 40 percent, to 329,000, by 2025.

Monroe said “Forget Me Not,” which also has toured the District and Philadelphia since launching in September 2013, aims to show African American families what
Alzheimer’s is like and encourage them to seek help for loved ones who may suffer from it. As part of the event, the network attempts to recruit audience members for a huge federally funded clinical trial.

Yet even among those interested enough to attend the play, several expressed reluctance to participate in medical research. All of them agreed, with one word: Tuskegee, and its shameful legacy. That refers to a 1932 medical study for which the federal government enlisted about 400 low-income black men suffering from syphilis without informing them of their options and allowed some to go untreated after penicillin became available.

“I think for very good reasons in minority communities there is distrust of clinical trials,” said Reisa A. Sperling, a Harvard Medical School neurology professor and director of Alzheimer’s research at Brigham and Women’s Hospital who encouraged audience members to enroll in her research.

Sperling is the principal investigator of a study involving 60 sites in the United States, Canada and Australia attempting to learn whether regular transfusions of an antibody will stop the cascading series of events that lead to memory loss, cognitive impairment and, eventually, death.

The A4 study, as it’s called, targets beta amyloid, a protein whose buildup is the precursor to Alzheimer’s. Aging adults who have signs of amyloid buildup but no symptoms of cognitive impairment receive infusions of an antibody in the hope of sweeping the deposits from the brain. The study is funded in part by a $36 million grant from the National Institutes of Health, which has stipulated that organizers must work to boost minority representation in the trial.

African Americans are at increased risk of Alzheimer’s disease because of a complex mix of factors. For starters, African Americans are about 1.4 times more likely than whites to carry the apolipoprotein E (APOE) e4 gene variant, which consistently has been identified as a risk factor for Alzheimer’s. APOE is a key component of high-density lipids (HDL) and plays a central role in transporting cholesterol in the brain.

“We know for a fact that it does catalyze or promote development of the disease and that African Americans have higher occurrence of the gene,” said Thomas O. Obisesan, a physician and researcher at Howard University.

Oddly, the risk of developing disease associated with that gene in African Americans is less than the risk associated with that gene in whites, Obisesan said. But that is perhaps because fewer blacks live long enough to develop Alzheimer’s, often because of other ailments, such as cardiovascular disease, he said.

What’s more, researchers recently identified another gene that appears to raise the Alzheimer’s risk for African Americans, Obisesan said. The gene — ABCA7, which is involved in cholesterol metabolism and acts as a transporter between cellular membranes — was found to make blacks about 1.8 times as likely as whites to develop Alzheimer’s.

Other scientists think that African Americans may be at greater risk for Alzheimer’s because they also are at greater risk for diabetes, hypertension and cardiovascular disease, which contribute to development of the disease. Socioeconomic factors, such as more limited access to medical care and poor diet, also play a role.

“It’s very clear that these issues are related to poverty,” said Laurie M. Ryan, chief of the Dementias of Aging Branch in the National Institute on Aging’s neuroscience division.

Another possible factor, researchers said, is the stress that comes from enduring discrimination.

Stress has long been known to raise the risk of Alzheimer’s, and Lisa Barnes, a neurology professor at Rush University Medical Center, said that this finding has been borne out in her work, an epidemiological study focusing on African Americans since 2004.

“I think the most striking thing is the importance of social factors, such as perceived discrimination, social resources and purpose of life,” Barnes said.

Lower education levels among blacks also heighten risk. Researchers hypothesize that a limited education fails to create the rich network of connections among brain cells used in memory and cognition. When dementia begins, minor deterioration has a bigger effect. The analogy often used is one of bandwidth: It takes less time to degrade a narrow data-handling network than a large one.

“Early education has a profound effect on our cognitive function throughout your entire life,” said Jennifer Manly, a neurology professor at the Taub Institute for Research on Alzheimer’s Disease and the Aging Brain at Columbia University Medical Center. “And it turns out to have a profound effect on your risk for cognitive decline and developing Alzheimer’s disease.”

Education also affects African Americans’ perception of Alzheimer’s, as do cultural biases.

A 2007 caregivers’ survey for the Alzheimer’s Foundation of America found that African Americans were more likely to view Alzheimer’s as part of normal aging. Seventy percent of blacks also dismissed the disease’s symptoms as signs of old age, compared with 53 percent of other non-Hispanic ethnic groups.

“Not many African Americans are aware that Alzheimer’s disease is, per se, a disease,” said Kebreten F. Manaye, a physician and neuroscience professor at Howard University. “And so they don’t seek help at an early age when the disease happens.”

The survey for the Alzheimer’s Foundation of America also found that African Americans were more concerned about the “stigma” of Alzheimer’s, an attitude held by both victims and their caregivers that led to delays in seeking medical treatment. A different study, published in 2005 in the Journal of the American Geriatrics Society, found delays as long as seven years, at least in part because it was difficult to face the possibility that the patient might have dementia.

Changing those attitudes is what brought scientists and actors to Roxbury Community College’s Mainstage Theater on a recent Saturday. Organizers, including the NAACP and Black Ministerial Alliance of Greater Boston, fanned out in the African American community to invite people to attend.

“I literally went to every single black church in the Boston area,” said Tamy-Feé Meneide, clinical research diversity coordinator in Sperling’s lab.

At the door of the Roxbury Community College stage, invitees were offered chocolates and squeezable toys that resembled the human brain. After the show, the crowd was invited to stay for a panel with Brigham and Women’s Sperling and others to discuss Alzheimer’s.

Clyde Thomas, 68, of Hyde Park, Mass., said Alzheimer’s first ravaged his grandmother. Now his mother has it.

“I’m also concerned about it myself,” Thomas said. He said he wasn’t surprised that he and other African Americans were more at risk. “Maybe it’s what we’ve gone through — the stress of coming up, the result of what you lived.”