NEW YORK — As the owner of a successful acupuncture clinic in a wealthy Washington suburb, David Vandenberg never had any problems making a $433 monthly child support payment.

Until last year, when his business faltered and he went on unemployment. Unable to find another job, the 50-year-old Vandenberg moved to Arkansas to live with his parents. Now they're paying the child support for him.

"I felt I didn't have any recourse," said Vandenberg, who has a 12-year-old daughter and tried unsuccessfully for a court-approved reduction in his child support payments. After child support, "I get $100 a month in unemployment."

With the economic downturn hitting men harder than women — 9.8 versus 7.5 percent unemployment — and men comprising most noncustodial parents, many dads are finding themselves struggling to make child support payments that were based on incomes they no longer earn.

In a survey of the American Academy of Matrimonial Lawyers earlier this year, 39 percent of the members reported an increase in modifications being made to child support payments, and 42 percent cited a rise in the number of changes made to alimony.

"You have all these guys losing their jobs, having to take lower paying jobs or part-time work and they are flooding the courts to get downward modifications," said Glenn Sacks, executive director of Fathers & Families, which advocates for reform of the family court system. "The courts have improved to a degree, but they move much too slowly."

The Maryland Child Support Enforcement Administration has seen an 18 percent increase over the last year in requests for child support modifications, said Paula Tolson, spokeswoman for the state Department of Human Resources.

In Prince George's County, requests have tripled over the past 1 1/2 years. While historically requests have come from custodial parents who need an increase in support, many are now coming from noncustodial parents seeking a reduction, according to Joan Kennedy, director of the county's Office of Child Support Enforcement.

Many times the custodial parent feels the hit from a downward modification. Sometimes she has experienced her own income loss.

Delaine Moore, a separated stay-at-home mom of three in Calgary, Alberta, Canada, said there have been fewer trips to the movies and McDonald's and more activities at home since her ex's oil field drilling work came to a halt in March. Her child support and spousal payments dropped from $6,500 a month to nothing. He has since picked up a part-time job earning minimum wage but is only paying $450 a month.

Moore, who blogs about motherhood, divorce and infidelity, said her parents are paying her mortgage and she had money saved, but she is considering turning her home into a day care to earn money. If things haven't improved by Christmas, she may move in with her parents.

"I think my children are still feeling very loved and most importantly I'm here for them," she said. But it's been stressful. "I don't know what's going to happen."

Child support laws vary from state to state, but the amount is primarily based on the noncustodial parent's income. Other factors include how many children there are, how much time the children spend with each parent and the custodial parent's income.

In New York, a noncustodial parent making less than $80,000 pays 17 percent — less taxes — for one child, 25 percent for two children and 29 percent for three children, plus add-ons such as child care, medical expenses and extracurricular activities. But a reduction in income is not automatic grounds for a modification, said Eyal Talassazan, a divorce attorney in Great Neck, N.Y. Courts are often reluctant to disrupt children's lives.

Family court judge Patricia Macias of El Paso, Texas, said she considers whether the parent is unemployed or underemployed by choice, is actively seeking another job and can retain a job commensurate with their education and skills. Perhaps the person has assets that can be liquidated, she said.

"I believe that family court judges as a general rule are very empathetic to the economic situation," said Macias, immediate past president of the National Council of Juvenile and Family Court Judges. "But our primary focus is what the kids need. So that it's not good enough to say, 'Judge, you understand. We're in hard economic times.' We all understand but what extra effort are you making now?"

In some ways, the economy has made ex-spouses more willing to work things out on their own, said Ike Vanden Eykel of Koons, Fuller, Vanden Eykel & Robertson, a law firm with four locations in North Texas. Parents who go that route still need to get the court order changed, he said.

Samantha Land, 39, of Huntington Beach, Calif., agreed to a 50 percent reduction in $3,700 a month for her 8-year-old son.

"I don't need that much money and his income was getting reduced," said Land, who works as an esthetician, a nonmedical skin care specialist, and a transcriptionist. "The funny thing is because I did that, and because I have been more agreeable he has been more willing to help me when I need help."

Jeremy Lavine, 29, of Tampa, Fla., is keeping his two kids half the time so he is not paying the full support amount. He said he inquired about a modification more than a year ago, but the Florida Department of Children and Families told him his industry was going to bounce back.

Lavine's child support payment is still $1,100 a month based on a $4,500 a month income, though he now makes only $1,500 a month repairing jet skis. He and his ex-wife are going to mediation to get the changes to custody and child support on the books.

But as everyone knows, divorce can be contentious. Many people don't believe what their ex-spouses tell them when it comes to finances. Specialists recommend that parents work in the best interest of the children.

"Always keep talking," said Vanden Eykel. "Reach an accord. These are unprecedented times. It takes a real level of cooperation to get through it."