Depression in young adulthood might increase risk for cognitive impairment in old age, a new UCSF study has found.
The study — which used predictive models to determine depressive symptoms over a lifetime — found that the chances of cognitive impairment were 73% higher for those estimated to have elevated depressive symptoms in early adulthood, and 43% higher for those estimated to have elevated depressive symptoms in mid- and later life.
The findings could create a new sense of urgency in treating young people with depression, as that might have the potential to help them later in life — especially as the COVID-19 pandemic continues to take a toll on the mental health of young people.
“It’s an important time to be aware of mental health,” said Dr. Willa Brenowitz, the first author on the study, adding it is imperative to recognize that mental health has a significant impact on physical health.
“One of the key questions is if identifying those with depression and treating them, especially early in life, could improve brain aging outcomes such as prevention of Alzheimer disease and other dementias,” Dr. Kristine Yaffe, a senior author of the study, said.
To Brenowitz, that potential for prevention could change lives.
“I’m an epidemiologist, so I’m from the perspective that prevention is the best way to reach a lot of people,” she said. “If there’s ways we can slightly move risk factors, that’s going to have a downstream effect on people developing dementia or even delaying a dementia diagnosis.”
Brenowitz added that even keeping someone at a mild level of cognitive impairment for longer has a significant emotional and economic benefit for the family — “You’re not doomed to a certain outcome,” she said.
Many dementia and cognitive impairment studies tend to focus on older adults, which means that it’s hard to tell if symptoms like depression actually contribute to causing dementia, or if they’re just an early sign of it, Brenowitz explained. By focusing on earlier stages in life, this study attempts to start answering that question — is depression a risk factor for cognitive impairment in old age?
This study suggests that answer is yes, Brenowitz said.
The study pulled data from 15,000 people in different age cohorts, ranging from 20-89 — divided into older, midlife and young adulthood — and used predictive methods to estimate the average trajectory of depressive symptoms. That trajectory is used to make a “best guess” of how older adults with dementia might have been in early adulthood.
While this methodology isn’t as good as studying someone over a lifetime, Brenowitz said, it’s the best researchers have now — and should spotlight the need to start observation for dementia risk factors earlier in life.
“In terms of Alzheimer’s disease and dementia, it’s something you think about mostly with late life, but we really need to be doing what we can early in life if possible to address risk factors, particularly with depression,” she said.
Danielle Echeverria is a San Francisco Chronicle staff writer. Email: danielle.echeverria@sfchronicle.com Twitter: @DanielleEchev