The burden of student loan debt may affect the health and well-being of recent graduates, according to a study.

The first-of-a-kind study, led by researchers at the University of South Carolina and the University of California, Los Angeles, examined the relationship between student loans and early adult mental health. Two questions were explored: What is the association between the amount that students accrue during undergraduate studies and their mental well-being post graduation and what is the association between annual student loan borrowing and the mental well being of currently enrolled students? The team also looked at whether the relationship between student loan debt and mental health well-being as associated by the amount of money their family had, whether they attended a 2-year or 4-year college, and the degree they ultimately obtained.

The research team used data from the a survey representative of young adults in the United States. The findings revealed that those who had higher amounts of student debt reported higher levels of symptoms consistent with depression. Moreover, student loans were associated with poorer psychological functioning.

“We are speculating that part of the reasons that these types of loans are so stressful is the fact that you cannot defer them, they follow you for the rest of your life until you pay them off,” explained Katrina Walsemann, lead author. “We speculate that the American middle class is suffering the most from post-graduation debt, since they do not qualify for governmental assistance, nor is their family able to take on the bulk of the costs associated with college.”

According to background information provided in the press release announcing the results, in 2012, student loan debt totaled over $1 trillion in the United States, making this type of loan second only to home mortgage debt.

“The present findings raise novel questions for further research regarding student loan debt and the possible spillover effects on other life circumstances, such as occupational trajectories and health inequities,” the authors wrote. “The study of student loans is even more timely and significant given the ongoing rise in the costs of higher education.”

The study “Sick of our loans: Student borrowing and the mental health of young adults in the United States” was published in the journal Social Science & Medicine.