It's the cardinal rule of dating: do not hook up with your ex after a break-up under any circumstance.

But a new study published in a medical journal has found that 'ex-sex' may actually be a good way to help you move on from the relationship.

Researchers say those who slept with an ex were less likely to report feeling depressed and say they experienced more positive feelings on a day-to-day basis.

The team, from Wayne State University in Detroit, Michigan, says the findings show that sleeping with a former partner can actually lessen psychological distress caused by a break-up as well as provide people with the physical closure they need to move on.

A new study has found that people who said they slept with an ex were less likely to report feeling distressed and that they experienced more positive feelings on a day-to-day basis (file image)

For the report, published in the journal Archives of Sexual Behavior, the team conducted two studies.

In the first study, the researchers recruited 113 participants who had recently experienced a break-up.

Two months later, the adults filled out a survey, which asked questions such as had they attempted to have any physical contact with their exes, how emotionally attached they still were, and how they felt at the end of every day.

In the second study, 372 participants were asked to report the number of times they had attempted to have sex with their former partner - both successfully and unsuccessfully - and if they still felt emotionally attached.

The team said that they found that trying to hook up with an ex did not affect people's ability to recover from a break-up.

While the majority of participants who attempted to have sex with their ex ended up doing so, they did not report emotional attachment two months later.

Lead author Dr Stephanie Spielmann, a professor of psychology at Wayne State, said that those who were having more difficulty moving on were the ones who sought out sex the most with their former partner.

However, she said that when they did have a sexual encounter, it did not leave them distressed.

In fact, the participants reported more positive feelings on day-to-day basis.

'This research suggests that societal hand-wringing regarding trying to have sex with an ex may not be warranted,' said Dr Spielmann.

The fact that sex with an ex is found to be most eagerly pursued by those having difficulty moving on, suggests that we should perhaps instead more critically evaluate people's motivations behind pursuing sex with an ex.

For further research, Dr Spielmann says she wants to analyze people's feelings regarding break-ups over a longer period of time.

This is not the first time that research has suggested 'ex-sex' may not be as emotionally detrimental as once believed.

A 2012 study from the University of Arizona that looked at 137 recently divorced adults found whether or not breakup-sex helped a partner get over the end of their marriage depended on how 'over' it they already were.

Those who had not accepted the break-up said it lessened the pain of divorce while those who had accepted it said the encounter made no difference at all.

British sex and relationship expert Tracey Cox told the Daily Mail in 2013 that many women, in particular, benefit from sex with an ex because it gives them 'closure'.

'Sometimes we need to go back to move forward, and revisiting the sexual side of the relationship can sometimes make us see very clearly that we've idealized the relationship or feel much less pain than we thought,' she said. 'So there's a sense of closure that can be helpful.'