Among the array of strange and unexpected symptoms of COVID-19, a small but significant number of people are developing severe psychotic symptoms – from wild delusions to vivid hallucinations – after falling sick with the disease. Psychosis and pandemics have been linked before, nevertheless, researchers are struggling to understand why these peculiar symptoms are a feature of the ongoing disease outbreak.
While the precise scale of the problem is not yet clear, a number of studies across the world have investigated the issue over the past year.
One study, published in November, found that nearly 1 in 5 people diagnosed with COVID-19 receive a psychiatric diagnosis within the next 3 months. Shockingly, 1 in 4 of these people also had no previous history of mental health concerns before their infection. Most of these diagnoses were most often related to anxiety, depression, or insomnia – but over 1,200 of the patients were diagnosed with psychotic disorders. Another study looked at 153 people hospitalized with COVID-19 in the UK, and found that 10 of them had “new-onset psychosis” after their infection.
For some, the psychotic symptoms can linger. A case study of a 55-year-old woman in the UK explains how she experienced “persistent and florid psychotic symptoms” following a COVID-19 infection, despite having no history of mental illness. After being discharged from the hospital where she was being treated for COVID-19, she was readmitted just a few days later suffering from an array of unusual thoughts and behaviors. Along with acting confused, she started to believe her cat was a lion and saw “monkeys jumping out of the paramedic's bag.” She also believed that the nurses in the hospital were “devils” plotting to harm her, and that one of her family members had been replaced by a lookalike, known as a Capgras delusion. The patient continued to experience unsettling delusions for 34 days but eventually stopped reporting paranoid thoughts 52 days after her symptoms first emerged.
The question is, what's causing these psychotic experiences? There is an argument that it could be, in some small part, a reflection of how many people have suffered from mental health problems during the pandemic due to social isolation, anxiety about the illness, and financial problems. Broadly speaking, it’s also known that many physical illnesses can also trigger mental health problems.
There is also a bunch of strong evidence that COVID-19 is involved in a range of brain complications and neurological symptoms, from strokes and seizures to memory loss to a lack of concentration, something referred to as “brain fog”. Paired with this, research has also identified physical changes to the brain associated with the disease. It remains uncertain, however, whether this is evidence of the virus directly “attacking” the brain tissue, or indirect damage caused by inflammation from the infection.
Oddly, there's a long history of mental illness and disease outbreaks. Karl Menninger, a psychiatrist at Boston Psychopathic Hospital, was one of many clinicians who noted that a surprising number of “mental disturbances” were documented in survivors of the Spanish flu pandemic of 1918. Researchers have also found some links – albeit less significant compared to COVID-19 – between the rise of mental health problems and other coronavirus outbreaks, such as SARS or MERS.
For more information about COVID-19, check out the IFLScience COVID-19 hub where you can follow the current state of the pandemic, the progress of vaccine development, and further insights into the disease.