The recession pushed more people in the Washington area into living with relatives and friends, according to new census figures showing a sharp rise in families who have taken in adult children, siblings, parents and roommates.

Almost 1.2 million of the region’s 6 million residents were living with extended family members and friends last year, a 33 percent rise over the past decade. Nationwide, according to recently released 2010 Census statistics, at least 54 million people are in a similar spot.

The figures represent a significant reversal in American lifestyles after decades in which extended-family households fell into disfavor and the nuclear family flourished in the suburbs.

“We haven’t seen anything like this since the Depression,” said Frances Goldscheider, a Brown University sociologist who has studied families and living arrangements. “Overwhelmingly, it’s the recession’s effect on people’s ability to maintain a house. You have the foreclosures on one hand, and no jobs on the other. That’s a pretty double whammy.”

The number of adult children living with their parents — one slice of the phenomenon — soared in the Washington suburbs and in the District compared with a decade ago. The biggest increase was in Virginia, which experienced a 45 percent leap. In Maryland, the jump was 40 percent; in the District, 29 percent.

Although the faltering economy is a major factor in the newfound togetherness, demographers and sociologists say the recession accelerated a shift that was already underway. Fueling the trend: baby boomers caring for aging parents, and the arrival of millions of Hispanic and Asian immigrants, who are more likely to live among several generations under one roof.

In the Washington region, blacks, Hispanics and Asians are all more likely than non-Hispanic whites to live in extended-family households. But all groups registered increases over the decade, in patterns that reflect cultural differences.

Blacks are more likely to have grandchildren living with them. Asians tend to have their parents in the house. Hispanics often share their homes with more distant relatives such as aunts and uncles or with people who are not relatives. Non-Hispanic whites have more adult children at home.

Two years after earning a physics degree from Carnegie Mellon University, Adam Schloss, 25, has moved back into his childhood bedroom in his parents’ house in Rockville. He worked for a while on political campaigns in Pittsburgh.

But when he got no job offers after sending out dozens of résumés, he quit resisting his parents’ entreaties to come home. He pays them rent from his earnings as a computer technician. He is taking classes in software development and is saving money for a place of his own. Many of his friends are living with their parents, too.

“It’s not because we want to,” he said. “In many cases, we may have no other choice. Either we’re unable to get a job, or, if we get one, we can’t afford to live on our own.”

Schloss’s sister has just graduated from Brandeis University. “She’ll probably be moving home, too,” he said.

Daniel Sherrett, 28, returned to Upper Marlboro after he graduated from the Culinary Institute of America with aspirations of becoming a sommelier. He lives in a converted garage apartment, decorated with his childhood rock and gem collection, and his “Transformers” movie posters.

He works as a waiter in a downtown hotel restaurant. He pays his mother rent and often cooks for her, and he looks after his older brother, who is autistic. His spare money goes to pay off loans for his education and his motorcycle.

“I prefer Lifetime television for women. He likes the Discovery Channel and some show about dirty jobs,” said his mother, Marie Sherrett, a legal secretary, whose five sisters all have either adult children or adult nieces living with them. “But it’s neat. You get companionship. In my case, you get someone to make you dinner.”

Increasingly, adult children are returning home after decades away.

Four generations — plus two dogs and a cat — now live in the home of Beverly Braun and her husband, Skip Loescher.

When the couple retired a few years ago, they sold their Capitol Hill house and moved to a three-bedroom home in Annapolis.

Braun’s mother moved in with them after they converted the garage to a one-bedroom apartment for her. And last year, her daughter, Leslie de Vries, moved in with her two teenage children after she got divorced and lost her home to foreclosure in Sacramento, where she had lived for 25 years. Braun’s granddaughter has since moved out, but her 18-year-old grandson has a “man cave” in the basement, while de Vries sleeps in a spare bedroom.

Braun describes the arrangement as a blessing.

“My 89-year-old mother is coping with T-shirts that say things her mother would have fainted at,” Braun said. “The key is to realize different is not a matter of right and wrong. There’s classical and country music, and people like them both. It’s the same with what you snack on and how you pass your time. For all the little hassles, we are blessed.”

De Vries, 45, said she considers it a gift to be able to live with her mother and stepfather. She does most of the cooking and cleaning and cares for her grandmother, and in return she has a place to live and a garden in the back yard.

“It’s been a wonderful experience,” she said. “You have to be careful about how much you re-create your old role, falling back into the old dynamic. I was very conscientious about maintaining good boundaries.”

Establishing boundaries was also important for Steve Jerrick when he and his partner decided they were living what he calls a “pre-2008 lifestyle” and needed some extra income. So they rented out a room of their Logan Circle house to a woman who answered their ad on Craigslist. But they set rules.

“We don’t expect each other to be available for socializing,” said Jerrick, a caterer. “We live two completely different lives. We don’t share friends. We share a house, not our lives.”

The strain of living together sometimes pulls people apart.

More than half of the people who contact the Hilda M. Barg Homeless Prevention Center, a shelter run by Volunteers of America Chesapeake in Prince William County, have been evicted by friends and family members, said program director Gayle Sanders.

Goldscheider said she thinks the number of extended families will start dipping once the economy improves. In the meantime, she sees benefits to the trend.

“I like silver linings,” she said. “One thing wrong with our system is that young people leave home at the peak of adolescent rebellion. When they come back as adults, they get a second chance to know [their parents] better.”