Large Study of Black Adults Points to Strategy to Slow Dementia

Encouraging older black adults with mild cognitive impairment (MCI) to increase their cognitive, physical, and/or social activities may help to slow cognitive decline, according to a study posted on September 10 in JAMA Neurology.

This study is not the first to suggest that staying mentally, physically, and socially active can help slow down cognitive decline; however, previous population studies in the United States have not included significant numbers of black individuals, so it was not known whether the cognitive benefits of staying active generalized to blacks.

This new study, led by investigators at Sidney Kimmel Medical College of Thomas Jefferson University in Philadelphia, enrolled 221 black adults aged 65 and older with MCI. The participants were randomly assigned to receive either behavioral activation or supported therapy over a two-year period. Behavioral activation uses strategies like setting goals and making action plans to reinforce a healthy lifestyle, while supportive therapy involves structured, empathic discussions with people about the experience of aging and memory loss but does not include any behavioral reinforcement strategies.

Participants in both groups received five in-home, hour-long treatment sessions over the first four months, followed by six in-home, hour-long follow-up sessions over the next 20 months. The sessions were administered by trained community health workers.

The participants were given cognitive tests and asked about their cognitive, physical, and social activities every six months. There were no significant differences in cognitive performance between the groups at six months, but in the subsequent follow-ups, the adults receiving behavioral activation began to perform better than those in the supportive therapy group.

The primary measurement was the number of participants whose scores on the Hopkins Verbal Learning Test (which tasks people to learn a set of words and then remember them after 20 to 25 minutes) declined by at least six points from baseline. Only 1 percent of the behavioral activation group had a significant decline after 24 months, compared with 9 percent in the supportive therapy group.

Lead study investigator Barry W. Rovner, M.D., a professor of psychiatry and neurology at Thomas Jefferson University, told Psychiatric News that using a preset cutoff on the Hopkins test could be seen as arbitrary; people might have dropped 4 or 5 points on their cognitive test scores and not be considered as showing a decline. To account for this, the investigators used additional statistical methods to compare cognitive decline.

“We found that if you looked at overall test performance over the two years, the participants in the behavioral activation group were half as likely to show any decline on the cognitive test at any given time point,” Rovner said.

In discussing why behavioral activation showed such significant results, Rovner noted that social determinants of health such as environment or income play a significant role in the dementia risk of blacks.

“Starting from conception, a time during which black mothers have higher rates of stress, poor nutrition, and less access to quality medical care, blacks face tremendous health disparities that break down their cognitive reserve and double their risk of dementia,” he said. “This study showed that if we intervene in that socioeconomic context and enrich these adults’ environments in a culturally sensitive way, we can overcome that adversity.”

Translating these controlled study findings to a real-world setting is challenging, Rovner admitted. Study participants received continual behavioral reinforcement from trained community workers, and many older black adults do not have access to such personnel in their communities. But that’s where family members can step in, he said. “That’s the way we can scale this up to the community level.”

Rovner said that the behavioral strategies employed do not even have to be very detailed if that proves difficult for family members. He noted that while behavioral activation is superior, the 9 percent decline in the supportive therapy group was encouraging. Epidemiological studies have suggested that up to 20 percent of black adults with MCI show significant cognitive decline over two years. That indicates that even a little bit of support and social interaction can benefit this population, he said.

This study was supported by a grant from the National Institute on Aging. ■

“Preventing Cognitive Decline in Black Individuals With Mild Cognitive Impairment: A Randomized Clinical Trial” can be accessed here.