HACKENSACK, N.J. — David Leibowitz, 56, sits in his living room and surveys with pride the handmade lamps, photo frames and knickknacks that fill his family’s comfortable Teaneck, N.J., home — a home he has twice refinanced to pay for his children’s college education.

“I wish, in 2001, somebody had given me the biggest, swiftest kick in the rear end and said, ‘Unless your children go to Harvard, Princeton or Yale, pretty much everything else is a level playing field.’”

The Leibowitzes are among the millions of American families saddled with the burden of student debt, and they are fortunate: There are no menacing phone calls from collectors, no threats of home foreclosure, no specter of default.

But as Leibowitz can attest, prolonged debt can slowly erode confidence, credit and opportunity, putting a strain on families as well as finances.

Last year, new student loans exceeded $100 billion nationwide for the first time. Total loans outstanding will exceed $1 trillion this year. Students today borrow twice what they did just a decade ago, and Americans now owe more on student loans than on credit cards.

In the meantime, more and more American borrowers are defaulting on their federal student loans. The national two-year default rate rose to 8.8 percent in fiscal 2009, from 7 percent in 2008, according to figures released last month by the Department of Education.

Today, many students struggle to pay off these loans on their own, facing limited employment options. When parents take on this college debt, these monthly payments often entail serious household sacrifices, and can yoke children to parents for years.

Lifestyle adjustments

Leibowitz’s daughter, Alison, graduated from Teaneck High in 2002 and matriculated at the University of Maryland-College Park.

“When I went to college, my parents, like everybody’s parents, said they would pay,” Alison Leibowitz said. But in 2005, her younger brother Jake entered college, and David Leibowitz felt the strain.

“I saw no hope and no relief, and my mental health was at stake,” he said. He took out a $30,000 loan.

Today, Alison Leibowitz lives at home with her parents, commuting to Englewood, N.J., each day, where she works as a graphic designer.

After years of selling off assets and managing stocks to cover expenses, David Leibowitz recently refinanced their home, taking advantage of low interest rates to consolidate some $70,000 in accumulated credit card and student loan debt.

Alison Leibowitz said her parents — her dad works in film, her mother is a school nurse — have changed their lifestyle.

“The biggest difference between now and when I graduated, they used to go out to dinner all the time … and now? Never, ever.”

Struggling

David Amdur graduated from Teaneck High in 2000 and also attended the University of Maryland, taking out “tens of thousands” in federal loans.

“My father said he would pay for anything essential — dormitory housing, books, classes,” Amdur said. “Anything else was my own dime.”

Amdur worked part-time in the alumni office to cover the difference. But after graduation, Amdur struggled to find a job, drifting in and out of employment and his parents’ home.

Seven years after graduation, Amdur has a full-time job and an apartment he pays for himself. His parents are still paying off his loans. “My parents have been really good about it,” he said.

‘No way out’

David Lisco, 30, lives at home with his parents in Whippany, N.J. Each month, more than half of his $2,000 income goes toward the interest on his student loans. He sees no way out of his $140,000 debt.

“I’ve tried to work things out,” Lisco said. “I’ve been working since graduation, and I’ve been making steady payments. I’ve never defaulted.”

After graduating in 1999 from Whippany Park High School, Lisco attended Pace University in New York, but withdrew due to academic troubles. He graduated from William Paterson University in 2007.

Lisco’s parents paid for his time at Pace, but to cover the rest of his schooling and related expenses, Lisco took out $75,000 in loans from Sallie Mae, plus “about $20,000” in federal and small bank loans. By the time he graduated, Lisco said, he owed Sallie Mae alone nearly $100,000.

Since then, despite his job as a financial analyst, Lisco has struggled to pay off his debt. A few years ago, Lisco filed for bankruptcy, which cannot dissolve student loan obligations but eliminated his hefty credit card bills. His federal loan is in forbearance, but Lisco owes $800 each month — that’s interest alone — to Sallie Mae, plus a few hundred more in private loan interest.

“When I first started taking out loans, I don’t feel I was particularly informed,” he said. “Obviously, it’s my responsibility to look into the numbers, but when you’re young, you don’t know how to do that stuff.”

This regret is among the more resounding lessons indebted students and families list: They didn’t think before committing themselves to college, to a major and to tens of thousands of dollars in debt.

“I’m not saying college isn’t worth it,” David Leibowitz said. “But parents acquiesce, they pay the bill, and when it’s all said and done, there are no guarantees. My children are both happy; they both have their degrees. Whether those degrees are worth anything, I don’t know. That remains to be seen.”