Forcing teenagers who fail GCSEs into multiple resits has a negative impact on their mental health, according to research to be published as pupils receive their grades on Thursday.

The study by academics at University College London (UCL) compared the mental wellbeing of students in England, Wales and Northern Ireland who failed to reach a grade 4 or equivalent in maths or English GCSEs – and found that only those in England, where resits are mandatory, showed significantly lower wellbeing.

Robbie Maris, a research fellow at UCL and one of the authors, said the dent to teenagers’ self-confidence when faced with resits could be a contributing factor to the rise in young people not in education, employment or training, known as Neets.

Maris said: “Some [resitting] students will not turn up for their exams, they won’t enter them or they will drop out of education – these are the kids at highest risk of dropping out of education and becoming Neets.

“It could be leading to further disengagement, which is a worrying thing. People need to pay more attention to this, because if you demotivate or demoralise young people it puts them at risk of dropping out of the education system entirely.”

The resits policy in England was introduced in 2014 and requires students who have not achieved a grade 4 pass in English or maths GCSE at age 16 to continue to study those qualifications as a condition of their further education or college places being funded.

This year, about 180,000 students who sat GCSEs last year will retake GCSE English and about 175,000 are expected to retake maths, after record numbers of 16-year-olds last year received grades below 4.

Maris said the comparison between students with similar academic records in Wales and Northern Ireland and those in England, after adjusting for other factors, left the resits policy as a major difference between the two groups.

“We see no impact really at all for failing English and maths in Wales or Northern Ireland but in England there’s a relatively large negative impact. This is strong evidence that it’s something to do with England’s policy setting that is generating these impacts,” Maris said.

The study, to be published as a working paper by UCL’s centre for education policy and equalising opportunities, also found considerable differences between girls and boys. The biggest impact on girls was on those who narrowly missed out on a grade 4 in maths, while for boys the biggest impact was among those who were “substantially below” the threshold for a passing grade in English.

In contrast, boys who failed to get a 4 in maths, and girls who failed in English, showed little or no downturn in wellbeing.

“Girls already have low self-efficacy and anxiety in maths, on average, and we’ve got similar issues with boys doing English, anecdotally a lot of boys don’t like doing English. Being forced to resit these subjects where there are these particularly strong gender norms have large effects on boys and girls, it’s a very interesting pattern that emerges,” said Maris, adding that further research would be needed to explain why it occurred.

The mandatory resits policy for those remaining in education has been controversial since its introduction, with the success rate among 17- to 19-year-olds falling in recent years. Last year, fewer than 20% in the resitting age group received a grade 4 or above in English, while in maths about 15% got a 4 or better, and fewer than one in 100 got a grade 9.

Angela Rayner, the then shadow education secretary, said in 2018 that a Labour government would scrap compulsory resits. But the skills white paper published last year left resits in place while proposing a new “stepping stone” qualification for resitting students with grade 2 or below.

The Department for Education said: “We know that resitting exams repeatedly without improving grades can be demoralising, which is why we’re taking action to break the endless cycle of resits.

“Our new 16-19 English and maths qualifications will properly prepare students before they resit their GCSE – with changes to the accountability framework to support this and ensure students only sit an exam when they are ready to progress.

“We have also ensured that students will get at least 100 hours of teaching per subject, backed by extra funding and free teacher training, so they progress with a genuine chance of success.”

This year’s resits may see some improvement in results after the government’s toughened requirement for providers to offer a minimum of 100 teaching hours for each subject, alongside increased funding.