Jean Clement has been an exorcist since 2010
© Magali Delporte/Magali DelporteJean Clement has been an exorcist since 2010
Exorcisms are experiencing a boom in popularity across several European countries. But with religious belief declining across the developed world, what is driving the demand for one of the Christian faith's most controversial practices?

France leads the way when it comes to the renewed interest in exorcism. In Ile-de-France, the region around Paris, the number of exorcism requests has remained relatively steady in recent years at around 2,500 per year. However, the Church now acts on around 50 of those reports of demonic possession, compared to an average of 15 a decade ago.

And what of those who aren't among the the 50 cases identified as a genuine demonic possession? Private exorcism services in the country are also booming, The Economist reports.

A French priest has a simple explanation for the apparent rise in possessions, telling expat magazine The Connexion that exorcisms were on the rise "because France is less religious, leaving people vulnerable to diabolical attacks".

However, one private exorcist, Philippe Moscato, told the Economist that he suspected the existential threat of terror might be driving the demand, saying he received an "incredible avalanche" of requests for his services after the spate of terror attacks targeting France in late 2015 and early 2016.

In addition to godlessness and terrorism, a papal endorsement might also have played a part in the uptick in exorcisms. In March, the Holy Father reminded priests that they had a duty to consult with specialists if they suspected diabolic activity in their parish.

Pope Francis did not mention demonic possession by name, instead referring to "spiritual disorders" caused by "supernatural forces", Huffington Post reports.

The pontiff's public backing has given renewed attention within the Church to a practice which younger priests have proven reluctant to embrace.

Last year, a 79-year-old exorcist in Rome told the BBC that, despite booming demand for his services, he was struggling to find successors.

"I told the bishop that I can't find anyone willing to do this," Father Vincenzo Taraborelli told the BBC, claiming many of the younger priests were "scared" to become involved in the demon-battling business.

The pope reminded priests to act with "great care and prudence" when requesting an exorcism, however, and specifically warned against confusing supernatural forces with mental illness.

Nonetheless, in July this year religious think tank Theos warned that exorcisms of the mentally ill were behind a sharp rise in the number of such ceremonies being carried out in the UK

The "astonishing increase in demand" for exorcisms in recent years was driven by the prevalence of the practice in some Pentecostal and evangelical churches, their research found, particularly in immigrant communities.

One chaplain told Theos that exorcisms of the mentally ill were a "classic example of well-meaning initiative with the potential for serious harm", saying that anything which might discourage those in need from seeking professional medical help "runs the risk of becoming a sort of spiritual abuse".