Average college student debt has more than doubled over the past six years as students increasingly resort to loans rather than grants to pay rising tuition fees, according to a national survey released earlier this month.

Average student debt has risen to $18,800, up from $8,200 six years ago, according to figures provided by Nellie organization, the nation's largest non-profit provider of student loans. Nellie Mae compiled these figures from a pool consisting of 65 percent undergraduate borrowers and 35 percent graduate borrowers.

This increase in student debts can be attributed to a change in federal financial-aid policies.

"Government policy has shifted in the last 20 years from providing about 80 percent grants and 20 percent loans to just the opposite," said James S. Miller, Harvard's director of financial aid.

Nellie May's survey provided slightly different statistics which nevertheless reflect the same trend from grants toward loans. The survey said that in 1981, federal grants made up about 55 percent of student financial aid. By 1995, only 40 percent of federal financial aid came in the form of grants and the rest in loans.

Because of Harvard's financial resources, Miller said, Harvard students on financial aid are generally less burdened than their peers at other institutions.

"We've been really lucky that loss of federal grants has been met by increases in institutional grants," he said.

Miller said that the average Harvard senior on financial aid will graduate beetween $15,000 and $20,000 in debt.

According to the survey, the average undergraduate at a private college accumulates a debt of $17,500.

Students at the Law and Medical schools accumulate far more substantial debts than undergraduates, Miller said.

According to the national survey, students in professional schools accumulated an average debt of $50,000.

"Most professional schools finance students with loans, as opposed to graduate schools of arts and sciences which use teaching fellowships to help finance people's educations," Miller said.

Miller said that Harvard tries very hard not to let debt accumulate to the point where it affects students' career paths.

"Every two years or so, we do a survey where we look at loan indebtedness and see how it influences career and graduate school choices," Miller said. "So far we have found no correlation between, for example, graduate school and career choices and student indebtedness."

The Nellie Mae survey found that students' debts affected their life decisions if not their careers. Forty percent of students with loans said their debts caused them to delay buying a home, while many others delayed buying cars or starting families.

Miller said that the Law School subsidizes student loans for graduates who go into low-paying, law-related fields like public service law.