Memory lapses are expected as we age, but there’s evidence that many younger people — in the prime of life, ages 20 to 50 — are losing their grip on thoughts, struggling to retain new information and retrieve old knowledge. Experts blame the way we live and the world we live in, abuzz with distracting technologies amid endless demands on our time and minds.

Dr. Andrew E. Budson, a Boston University neurologist who specializes in memory disorders in older adults, runs into younger people whenever he gives a talk. Inevitably, someone in their 30s or 40s will approach him afterward with: My memory is terrible. . . . I know I’m young, but I’m concerned I’m getting Alzheimer’s disease.

Last year, a New York Times analysis of Census Bureau data found that the percentage of working-age adults reporting “serious difficulty” remembering, concentrating, or making decisions increased from just under 3 percent to just under 4 percent since the start of the pandemic. Those numbers may not seem shocking, until you peer deeper: The spike comes after 15 years of little change and represents 1 million more younger people ages 18 to 44 who say they have trouble thinking and remembering.

And the census numbers probably don’t include people whose memory lapses cause more routine annoyances. Back in 2013, Dr. Gary Small worked with Gallup to survey 18,500 adults, and found that 14 percent of those ages 18 to 39 answered “yes” when asked if they had any problems with their memory.

Small, who is chair of psychiatry at Hackensack University Medical Center in New Jersey, says he doesn’t know if the incidence has increased since then. But if he were to conduct a study now, he says, his hypothesis would be that memory problems among the young have indeed grown — driven by rising stress, exploding technology use, lack of exercise, and poor diet, among other lifestyle factors. “There’s a lot of data that suggest that how we behave every day has a big impact on how much we remember,” Small says.

Stress, in particular, takes a toll on the brain, impairing concentration and focus. Small points to experiments in which young volunteers injected with cortisol, the stress hormone, suffered temporary memory impairment. “The good news is that it’s temporary, and other studies have shown that meditation, tai chi, relaxation exercises, not only can improve moods, but they can also improve cognitive function,” he says.

But in the absence of such measures, “Chronic stress can have a long-term effect,” says Charan Ranganath, a memory specialist at the University of California at Davis. “You’re basically bathing your brain in stress hormones. In the most extreme case, it can actually cause brain damage.”

Another possible factor in this wave of forgetting: long COVID. Brain fog and memory loss are key features of the syndrome, in which symptoms persist for weeks or years after an infection with COVID-19.

But Dr. Zeina Chemali, a Massachusetts General Hospital neuropsychiatrist, estimates that long COVID accounts for only about 10 percent of memory complaints. Which is not to say that COVID-19 is irrelevant. Rather, Chemali notes, the pandemic assaulted our brains in other ways: The incidence of depression and anxiety has soared, especially among the young, as have heavy drinking and drug use — all of which can affect memory and concentration.

It’s part of a more nebulous malaise. “People are showing up after the pandemic with complaints to say, ‘Hey, we’re not doing well. We’re not as we used to be,’” Chemali says.

She advises a visit to a primary care doctor, to see whether a straightforward, treatable medical cause, such as thyroid insufficiency, vitamin deficiency, or anemia, can explain memory problems. It’s also important to rule out dire possibilities such as early-onset Alzheimer’s, she adds, which, to be clear, is uncommon. The vast majority of Alzheimer’s cases occur after age 65.

When Rose (who asked to be identified only by her middle name, for privacy reasons) was working on her PhD in molecular pharmacology, she was so forgetful she needed a journal with reminders for the simplest tasks, such as buying groceries or eating lunch. Unable to plan, she relied on her sister to pick out her dress to wear to their mother’s wedding. “Everything just had to happen like 20 minutes before, because there was just not, I guess, the brain capacity to think ahead,” she says. “There was too much ‘now’ stress to think for the future.”

Everyone in her PhD program, Rose says, was “in the same boat,” with every waking hour devoted to meeting the expectations of their equally stressed-out advisers. To her surprise, within about six months of completing her graduate degree in 2021 and taking a job at a Boston biotech, her memory felt fully restored.

Now, at 32, Rose is attentive to her diet and comfortable in her Quincy home, where she and her wife feel accepted, unlike where they lived before. Her boss is adamant, she says, that “at 6 o’clock you go home and you stop and you don’t think about work.” With the reduced stress, Rose has no trouble conducting multiple experiments at a time and keeping track of appointments.

Technology challenges the brain in new ways. Throughout history, stories and narratives have helped embed memories, says BU’s Budson. “Now we’re asked to remember all sorts of random things — websites and usernames and passwords and security codes and PIN numbers.” Our memory systems, perhaps, did not evolve for such tasks, he says.

Elizabeth Kensinger, a Boston College psychology professor who studies memory, doubts that memory skills have actually declined; instead, she says, young minds may be inundated with “junk” such as social media posts and emails. “It’s all providing noise and clutter, and it’s making our brains have to work that much harder to keep track of the one actually important email that was in this long set of emails.”

Focusing on what’s most important takes a conscious effort. “Remembering isn’t something that just happens automatically,” Kensinger says. “It’s something that happens because we’re devoting effort to it.”

Lauren, a 44-year-old school counselor and mother of two in Pennsylvania, sees the problem in her own life. “There’s so much information at any given moment,” she says, “whether I’m on the computer for work, or I’m on my phone looking something up, or I’m making a hair appointment and have to look up the phone number. There’s just so much information coming in that it’s hard to sift through it.”

Lauren, who asked that her last name not be published, believes information overload has contributed to her recent difficulties recalling names and events, although the anxiety she suffers from and the stress of a recent divorce and relocation surely also play a role. In the summer, when she’s off from work and sleeping nine hours a night, her mind clears up.

“Right now,” Lauren admits during our interview, “I have my screen split. I’m working on emails, I’m doing an online training, and I’m talking to you — all of this right now.” She acknowledges that this “media multitasking” might also contribute to her problems.

Multitasking appears to tax the very brain systems involved with attention and memory. A Stanford study in 2020 found that those who had trouble sustaining their attention and those who engaged in media multitasking performed worse on memory tests.

In reality, the brain can fully focus on only one thing at a time. Those who “multitask” are just rapidly shifting their attention from screen to screen, project to project — and that constant switching comes with a cost. “It’s sort of programming your brain to have...a staccato type of thinking,” Small says. “You’re not really exploring questions in depth and solving problems.”

Even just having a smartphone nearby “can affect people’s attentional abilities,” says UC-Davis’s Ranganath. “And so if you’re more distracted, your memory is going to go down.”

Ranganath, a professor in the Center for Neuroscience and the department of psychology, recommends a return to “mono-tasking.” Scroll social media during scheduled moments when you need to take a break, rather than switching back and forth randomly. Ranganath turns off all alerts when he’s working, then rewards himself with a few moments on YouTube when it’s time to goof off.

He flags another hazard of smartphones: They encourage you to photograph and video your experiences. It’s counterintuitive, but focusing on recording an event prevents you from forming a memory of it. “If you are mindlessly taking pictures and videos of everything,” Ranganath says, “you’re not focusing on the sights and sounds and feelings, emotions and smells and all of these parts of the event that will give you a rich, detailed memory later.”

For Budson, chief of cognitive and behavioral neurology for the VA Boston Healthcare System, the bigger worry is an older device — the television. One study involving 500,000 people found that those who “watch more than an hour of television a day have worse memories,” he says. Americans on average watch two to three hours a day, with many gazing at the tube for as long as eight hours. “I think TV is much worse than smartphones,” Budson says. “Fooling around on your smartphone is probably a waste of time but it’s at least engaging, right? It causes you to do something, you’re interacting. With television you’re almost put into a trance where you’re just not doing anything.”

To stay sharp, the brain needs to be active. And to maintain a sharp brain, the body needs to be active too. The well-worn advice for heart health applies to the brain as well: Exercise regularly, eat mostly plants, avoid processed foods, and get enough sleep.

“When we sleep is when our memories turn from a short-term, temporary store to a long-term, permanent store,” Budson says. “And if we don’t allow ourselves to get enough high-quality sleep each night...we’re absolutely going to be impairing our memory.”

That 2013 study by Small, the one that found memory problems among the young, offered another interesting finding: “Regardless of your age, the more healthy lifestyle behaviors you engaged in, the better your memory,” he says. “Clearly, these kinds of behaviors that we know mitigate memory problems are important throughout the life span.”

That’s a lot of behaviors to change. To figure out where to begin, Chemali recommends filling out the Brain Care Score developed by Mass. General’s McCance Center for Brain Health. A brief questionnaire asks questions about your physical health (such as blood pressure and weight), your lifestyle (how much you exercise, what you eat), and your social and emotional well-being, including whether you feel a sense of purpose. A point value is assigned to each item, and you’ll get a score ranging up to 21 points.

The idea isn’t to reach 21 — nobody’s perfect. Instead, the score card can help you choose one aspect of your life to change, followed perhaps by another, so that you can start ticking the score upward.

This advice all sounds great. But the demands of real life can interfere, especially for parents. Braun, the music therapist, would love to take walks by herself or find a quiet spot to meditate. But her husband works late, their house in upstate New York is small, and her kids, ages 1 and 4, require her attention.

Still, when Braun can slip away to enjoy nature or meditate, or even take a long shower, she reaps the benefits. “Afterward,” she says, “I’m like, ‘Oh, wow, I sort of feel more like the me that I want to be.’”

Felice J. Freyer is a health reporter based in Rhode Island. Send comments to magazine@globe.com.