In the study, researchers asked gamers how much they spent on loot boxes on a monthly basis and then assessed them against the Problem Gambling Severity Index.
The study found: “The more severe that participants’ problem gambling was, the more money they spent on loot boxes.”
Mr Cairns added: “What we don’t know is how children are responding to this. If adults are having this link, what else maybe happening with children? As a parent I would be very concerned.”
Loot boxes are currently not classed as gambling by the Gambling Commission as their prizes are deemed to have no monetary value.
Following the study, Prof Mark Griffiths, of Nottingham Trent University and a leading expert on addiction, called on the Gambling Commission to alter its interpretation of the Gambling Act 2005 to include loot boxes.
He said: “To me loot boxes are gambling, they are akin to a lottery. Some people argue it’s not gambling if you always ‘win’ something, but the if the item you win is far less than the money you paid for, then for me that’s not really a win.
“The Gambling Commission will admit that loot boxes are gambling-like – I think most people would say they are gambling-like – even if they are not by their own definitions a form of gambling. I have argued that it is a form of gambling.