Anxiety about Brexit may have triggered a man’s psychotic episode, according to a U.K. doctor who is warning that a country’s political climate could have dire mental health effects.

Three weeks after a referendum determined in 2016 that the United Kingdom would leave the European Union, a man in his 40s was taken to hospital. His mental health had “deteriorated rapidly,” according to the new case report released Tuesday in the journal BMJ Case Reports. He had hallucinations, lost sleep and grew paranoid that people were spying on him.

“At the hospital he was agitated, perplexed and confused, attempting to dig the floor with his hands to ‘burrow’ through the floor to ‘get the hell out of this place,’” the report said. “He found it difficult to reconcile with the political events happening around him.”

The man, who described his family as “multicultural,” became increasingly worried about “racial incidents.” In a first-person section of the report detailing his perspective, the man said political parallels in the U.S. after Donald Trump’s election added to the unease.

“This was in the summer of 2016 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 U.S. and we were talking together on social media about racial issues,” the report reads. That year, a flurry of xenophobic and racist acts were reported in the U.K. following the European Union referendum. In the U.S., the alt-right movement supporting President Donald Trump’s campaign and eventual victory were drawing Nazi comparisons.

The man’s psychotic break appeared seemingly unexplained. While he had previously experienced a similar episode precipitated by work stress, that one was less severe, the report said. He had reported other pressures associated with family and work in 2016, but there was no family history of mental health problems, no history of substance abuse or significant health issues. He recovered quickly after he was given intramuscular lorazepam (a tranquilizer for anxiety) and prescribed olanzapine (an antipsychotic). The author of the report, Dr. Mohammad Zia Ul Haq Katshu, writes that while work and family stressors often impact mental health, the man’s episode makes a case that the political climate may play a significant role in some cases.

“Political events can act as major psychological stressors and have a significant impact on the mental health of people, especially those with a predisposition to develop mental illness,” he wrote.

This type of episode, called acute and transient psychotic disorder (ATPD), typically dissipates within a few months but can come on quickly within a few weeks of a trigger, according to the report. In this case, the man’s episode was three weeks after the EU referendum results were declared. Recent surveys confirm that political events may be a source of much stress. In the U.S., following Trump’s election, about two-thirds (66 per cent) of respondents said the future of the country was a significant source of anxiety, according to the American Psychological Association. Surveys in the U.K. about Brexit yielded comparable results about an anxious citizenry. Earlier this year, a therapist in London said she was seeing an increase in patients seeking help for Brexit stress. Similar mental health discussions are being had in the environmental arena in recent years as terms like “eco-anxiety” and “climate grief” were coined in response to concerns about climate change. But much research still needs to be done to understand how politics and the environment affect our health.