The rise of tuition fees does not have a long term impact on students' mental health, according to a recent study.

Researchers at the University of Southampton found that students paying the higher fees were less likely to experience an improvement in their state of mind during their first year of university, but that the increase had no longer term impact on their mental wellbeing.

"Previous studies have found a relationship between financial difficulties, levels of debt and poor mental health in British students," Dr. Thomas Richardson, lead author of the study, said in a statement. "This study suggests it may be the ability to pay the bills, rather than the size of the student loan itself, that is important to wellbeing while at university."

For the study, nearly 400 undergraduate students from universities across the United Kingdom completed surveys to assess levels of stress, depression, anxiety and other mental health issues during their first two years of study.

Surveys were completed online on four occasions, three to four months apart, and spanning students' first and second academic year at university.

The first survey showed no significant differences between the various groups. Differences became apparent at the second time of study, with those charged lower fees showing an improvement in anxiety, depression, stress and general mental health over time, while those charged more showed no improvement.

However by the third and fourth tests, the trend of worse mental health for those paying higher tuition fees had reversed, so there were no longer any differences between the groups based on fees.

Many students charged higher tuition fees will be graduating later this year.

"At present the tuition fees increase does not appear to have had a major impact on the mental health of undergraduates," Richardson said. "However differences between those charged higher fees may not become apparent for many years and so ongoing monitoring of the prevalence of mental health problems in students and their relationship with debt is needed."

The findings are detailed in the Journal of Public Health.