Other factors leading to poor grades -- including lack of sleep, illness and depression -- are stress-related as well, the report showed.
Richard Heisterman, director of consultation services at the University of Virginia, said students at UVa. are experiencing higher levels of stress than in previous years.
"There is an increased stress level on campus," Heisterman said. "We're seeing more acute-care types of issues."
The number of students coming into Appalachian State University's counseling center has increased, said Dan Jones, director of ASU's counseling center.
Jones attributed increased stress to students' having fewer familial support systems than in the past.
He also said the pressures of being a student athlete can be overwhelming in the modern college environment.
John Barrow, assistant director of counseling and psychological services at Duke University, said he has also noticed an increase in the stress level of students.
"There's all kind of stressors that are stirred up for students," he said.
Barrow said students in underrepresented groups -- such as racial, ethnic and sexual minorities -- often have more problems in the mainstream student body.