A man in the UK has been diagnosed with a psychotic disorder in what is believed to be the first case triggered by the Brexit referendum.

The unnamed patient, in his 40s, was taken to hospital three weeks after the UK voted to leave the EU in 2016, and was said to be experiencing paranoid, referential and bizarre delusions, according to a recent report in the British Medical Journal (BMJ).

He was also witnessed trying to "burrow" through the hospital floor with his hands to "get the hell out of this place".

The man was later admitted to a psychiatric ward, where he told people he was ashamed to be British, and was quoted as saying he had looked at an electoral map of the EU and found that his constituency "reflects an opinion that is not for me".

Describing his family as "multicultural," the patient had grown increasingly concerned about racial violence, which eventually turned into beliefs that he was being spied upon and people were plotting his murder.

He said in a later account that he had believed his wife's relatives wanted to "shoot a missile" at him "using heat-seeking technology", and so he had laid spread-eagled on his bed to provide the "best possible target".

"This was in the summer of 2016," he wrote in a report after his recovery.

"And, as well as my own anxieties about Brexit, it was also a time when a friend of mine was experiencing immense anxiety about what was happening around him in the US, and we were talking together on social media about racial issues."

He went on to discuss how he tried designing an algorithm for Facebook to connect a user's emojis to their experiences, but said he believed his wife destroyed it because it was "exacerbating my psychotic state".

He added: "I remember driving and hearing the radio presenters talking about me as if they could see me and knew what I was thinking.

"Many times, during these scenarios, I felt quite petrified."

"At one point when I was being held in a hospital interview room, I believed that we were in the basement of a tower block that was going to be pulled down in a 9/11 style attack.

"I spent the entire time studying the walls and exit doors and watching people through the narrow window in the fire door to try and work out whether they were entering or evacuating the building and if there was any hope of escape."

The patient, who had experienced a similar but less severe episode 13 years earlier amid work-related stress, was eventually diagnosed with acute and transient psychotic disorder (ATPD), and spent two weeks in a psychiatric ward - for some of which he was tranquilised.

He made a full recovery and was discharged weeks later.

The report's author, Dr Mohammad Zia Ul Haq Katshu, said that while this was the first reported case of Brexit-triggered ATPD, there had been a similar such case of a "brief psychotic episode" caused by stress from presidential election results in the United States.