Among the range of strange and unexpected symptoms of COVID-19, a small but significant number of people develop severe psychotic symptoms – from wild delusions to clear hallucinations – after becoming ill with the disease. Psychosis and pandemics have been linked in the past, but researchers are struggling to understand why these peculiar symptoms are a hallmark of the ongoing disease outbreak.
Although the exact extent of the problem is not yet clear, a number of studies around the world have examined it in recent years.
A study, published in November, found that nearly 1 in 5 people diagnosed with COVID-19 will receive a psychiatric diagnosis within the next three months. Shockingly enough, 1 in 4 of these people also had no previous history of mental health before being infected. Most of these diagnoses are mostly related to anxiety, depression or insomnia – but more than 1,200 of the patients were diagnosed with psychotic disorders. Another study looked at 153 people hospitalized in the UK with COVID-19, and found that 10 of them had a new psychosis after their infection.
For some, the psychotic symptoms may linger. A case study of a 55-year-old woman in the UK explains how she experienced “persistent and florid psychotic symptoms” after a COVID-19 infection, although she had no history of mental illness. After being discharged from the hospital where she was treated for COVID-19, she was readmitted only a few days later and suffered from a variety of unusual thoughts and behaviors. Along with confused acting, she began to believe that her cat was a lion and saw “monkeys jump out of the paramedic’s pocket.” She also believed that the nurses in the hospital were planning ‘devils’ to harm her, and that one of her family members had been replaced by a similar one, known as a Capgras delusion. The patient continued to experience disturbing errors for 34 days, but eventually stopped reporting paranoid thoughts 52 days after her symptoms first appeared.
The question is, what causes these psychotic experiences? There is an argument that this may to a small extent be a reflection of how many people suffered from mental health problems pandemic due to social isolation, anxiety about the disease and financial problems. In general, it is also known that many physical illnesses can also cause mental health problems.
There is also a wealth of strong evidence that COVID-19 is involved in a range of brain complications and neurological symptoms, from strokes and attacks to memory loss to a lack of concentration, something referred to as “brain fog”. Linked to this, research has also identified physical changes to the brain associated with the disease. However, it remains uncertain whether this is evidence that the virus “attacks” the brain tissue directly, or indirectly causes damage due to inflammation caused by the infection.
Oddly enough, there is a long history of mental illness and disease outbreaks. Karl Menninger, a psychiatrist at Boston Psychopathic Hospital, was one of the many clinicians who noticed that a surprising number of “mental disorders” have been documented in survivors of the 1918 Spanish flu pandemic. Researchers have also found some links – though less important compared to COVID-19 – between the onset of mental health problems and other coronavirus outbreaks, such as SARS or MERS.
For more information on COVID-19, consult the IFLScience COVID-19 hub where you can track the current state of the pandemic, the progress of vaccine development, and further insights into the disease.