Conducted by a group of researchers across the UK led by the University of Oxford and the University of Leicester, and published in Lancet Psychiatry, the research highlights the persistent and significant nature of these symptoms as well as the emergence of new symptoms years after COVID-19 was first present.
The research was conducted with 475 participants (as part of the PHOSP-COVID study) who were invited to complete a set of cognitive tests via their computer and to report their symptoms of depression, anxiety, fatigue and their subjective perception of memory problems. They were also asked whether they had changed their occupation and why.
The researchers found:
- Two to three years after being infected with COVID-19, participants scored on average significantly lower in cognitive tests (test of attention and memory) than expected. The average deficit was equivalent to 10 IQ points. Additionally, a substantial proportion reported severe symptoms of depression (about 1 in 5 people), anxiety (1 in 8), fatigue (1 in 4), and subjective memory problems (1 in 4), with these symptoms worsening over time.
- Although in many people these symptoms at 2-3 years were already present 6 months post-infection, some people also experienced new symptoms 2 to 3 years after their infection that they were not experiencing before. New symptoms often emerged in individuals who already exhibited other symptoms at six months post-infection. This suggests that early symptoms can be predictive of later, more severe issues, underscoring the importance of timely management.
- More than one in four participants reported changing their occupation and many gave poor health as a reason. Occupation change was strongly associated with cognitive deficits and not with depression or anxiety. This suggests that many people who changed occupation in the months and years after COVID-19 did so because they could no longer meet the cognitive demands of their job rather than for lack of energy, interest, or confidence.
- The degree of recovery at six months post-COVID-19 is a strong predictor of longer-term psychiatric and cognitive outcomes. Intervening early to manage symptoms could prevent the development of more complex syndromes and improve overall recovery trajectories.