Finding it hard to get that student-debt monkey off your back? You're not the only one.

A study in the January edition of Social Science & Medicine has found evidence that high levels of student debt are linked to negative psychological impacts like depression, stress and generally worse mental health.

The study: University of South Carolina researchers surveyed 4,600 students and degree holders ages 25-31, asking them to complete five questions that acted as markers of psychological health. They then took those results and compared them to the levels of student loan debt each respondent held.

The researchers found that even when controlling for factors like income levels or family wealth, "cumulative student loans were significantly and inversely associated with better psychological functioning." They also found an effect for "yearly student loans borrowed," suggesting that both having high levels of debt and taking the large loans out in the first place were stressing the respondents out.

The study also found "occupational trajectories" and "health inequities" were impacted among student debt holders, meaning that loans may be forcing students and graduates off their preferred career paths and to delay getting married or starting a family.

Generation Progress' Lucy Stratton adds that Gallup poll findings from last year showed a 15-point "thriving gap" between indebted and debt-free students, with the indebted students doing worse in four out of five measurements of health.

As the Brookings Institution noted, the study can't tell us whether student loans are more stressful than other kinds of debt. The size of the measured effect was also rather small. But with former students holding an estimated $1.2 trillion in student loan debt across the country, and an average debt load of nearly $30,000,college loans are probably one of the biggest sources of debt-related stress in the country. A recent Federal Reserve survey estimated that student loan debt has increased 250% in the past three decades, even after adjusted for inflation. Americans only owe more on home mortgages.

"We are speculating that part of the reason 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," lead author Katrina Walsemann told ScienceDaily. "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."

Why you should care: Knowing that research is proving student loans are so stressful they have negative impacts on the mind and body isn't going to help them go away. But it is slightly comforting to know that stressed-out loan holders are in good company: the rest of their generation. If paying back student loans is a constant shadow over your life, at least you're not alone.

But with the number of 25-year-olds with student loan debt now around 45%, up from 25% a decade ago, entering adulthood is becoming a more challenging task for the legions of graduates who are hindered by seemingly insurmountable levels of debt. Paying off those loans comes at the cost of other things young Americans might want to do, such as saving for retirement. It's a bad situation to be in, and one that seems to be getting worse, not better.