Health issues and brain fog can persist for years in individuals who were hospitalised with Covid-19 early in the pandemic, with some patients developing new or more severe symptoms after 12 months, according to researchers.
Their study revealed that while many with long Covid showed improvement over time, a significant portion still experienced cognitive difficulties two to three years later. Symptoms such as depression, anxiety, and fatigue often worsened rather than improved. The research focused on 475 people hospitalised with Covid-19 before vaccines were available, examining whether cognitive issues, fatigue, and mental health problems persisted or emerged beyond the first year.
Although the researchers lacked data on participants' cognitive function prior to Covid-19, tests conducted two to three years later showed that, on average, patients' IQs were 10 points lower than expected based on their age, education, and other factors. One in nine participants exhibited "severe cognitive deficits," reflecting an IQ 30 points lower than expected.
Questionnaires completed by participants revealed that many experienced moderate to severe levels of depression (47 per cent), fatigue (40 per cent), and anxiety (27 per cent) two to three years after their Covid-19 infection. These symptoms, rather than improving, were on average worse than they were six to 12 months after infection.
Over a quarter of the study participants changed occupations after contracting the virus, often due to the cognitive demands of their previous jobs becoming unmanageable. Those who had been most severely ill six months after infection tended to fare worse in the long term, though the severity of the initial illness did not seem to impact their long-term outcomes.
Despite an increase in reports of depression, anxiety, and fatigue after six months, cognitive problems appeared to improve slightly. Six months post-infection, 44 per cent of participants had objective cognitive deficits compared to 33 per cent at two to three years.
According to the Office for National Statistics, the number of people with long Covid is rising, with 2 million individuals in England and Scotland currently experiencing symptoms. Recent research indicates that the brain fog reported by many is equivalent to a six-point drop in IQ.
