Brexit isn't just creating a turbulent and unstable atmosphere in the United Kingdom right now. It can actually be harmful to the mental health of individuals, a new case report has warned. The stress generated by the 2016 Brexit referendum was so severe, for one man it actually led to severe psychosis.

According to the man's doctor, the case highlights how badly unstable political climates can affect the psychologically vulnerable.

In 2016, the world watched as the United Kingdom made the decision to formally remove itself from the European Union - a rending that will have profound economic impacts and may ultimately see the nation fragment.

It's fair to say that Brexit has caused a great deal of stress and anxiety to a great many people. In this one case, it was the tipping point over which the patient tumbled into free-fall psychosis.

The Brexit referendum results were revealed in June 2016. The verdict was in: Britain was going to exit, stage left, from the EU.

The man, in his 40s, was brought into the emergency department of a Nottingham hospital three weeks later in an absolute state: confused, agitated, talking nonsense, and so paranoid he thought voices on the TV and radio were talking about him.

He had no family history of mental illness; but on one occasion 13 years prior, he had experienced a similar incident, due to work stress. That incident was much less severe, and he recovered within a few days.

His wife told hospital staff that he had been becoming increasingly agitated about the referendum results - anxious about racially motivated violence, sleeping poorly, having escalating paranoia, auditory hallucinations, and delusions. At one point, he told hospital staff he was ashamed to be British.

"The best way that I can describe my experiences of psychosis are as intense periods of accelerated thinking, of being distracted and consumed by my own thoughts, and of a series of theatrical episodes of which I am at the centre, sometimes featuring friends or relatives from my own past," the patient said.

"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."

Before the referendum results, the patient was already considerably stressed due to work and family pressures. Combined with the previous psychotic episode, this suggests that he was vulnerable to the added stress of a significant political event, the doctor said.

The patient was dispatched to a psychiatric hospital, where he was sedated with  lorazepam due to his extreme agitation, then switched to the antipsychotic medication olanzapine.

Two weeks later, he was completely recovered and could be discharged. According to the report, the patient was able to reduce and eventually stop the olanzapine medication, and has since remained fine.

This case study is not just a curiosity, though. It suggests that significant political events - not just Brexit - could be triggers for episodes of acute mental illness, and doctors should be aware of this possibility.

The report has been published in BMJ Case Reports.