Increased risk of some neurological and psychiatric disorders remains 2 years after COVID-19 infection

18 August 2022

  • New diagnoses of disorders including psychosis, dementia, seizures and ‘brain fog’ remain commoner 2 years after COVID-19 than after other respiratory infections
  • In contrast, the increased risks of depression and anxiety after COVID-19 are short-lived and there is no overall excess of cases
  • Children have a more benign profile but are also at increased risk of some disorders after COVID-19
  • Results appear similar with the omicron variant as with delta

Published in The Lancet Psychiatry, this new study from the University of Oxford and the National Institute for Health and Care Research (NIHR) Oxford Health Biomedical Research Centre investigated neurological and psychiatric diagnoses in over 1.25 million people following diagnosed COVID-19 infection, using data from the US-based TriNetX electronic health record network.

The study reports on 14 neurological and psychiatric diagnoses over a 2-year period and compares their frequency with a matched group of people recovering from other respiratory infections. It also reports data in children and older adults separately, and compares data across three waves of the pandemic. To our knowledge, these are the first robust data addressing these important questions.

Confirming previous studies, many of the disorders are more common after COVID-19. Notably, the increased risk of anxiety and depression subsides within two months of COVID-19 and, over the whole 2-year period, are no more likely to occur than after other respiratory infections. In contrast, diagnoses of many neurological disorders (such as dementia and seizures), as well as psychotic disorders and ‘brain fog’, continue to be made more often after COVID-19 throughout the 2 years.

Results in children (under 18) showed similarities and differences to adults. The likelihood of most diagnoses after COVID-19 was lower than in adults, and they were not at greater risk of anxiety or depression than children who had other respiratory infections. However, like adults, children recovering from COVID-19 were more likely to be diagnosed with some conditions, including seizures and psychotic disorders.

More neurological and psychiatric disorders were seen during the delta variant wave than with the prior alpha variant. The omicron wave is associated with similar neurological and psychiatric risks as delta.

The study has several limitations. It is not known how severe, or how long-lasting, the disorders are. Nor is it clear when they began, since problems may be present for some time before a diagnosis is made. Unrecorded cases of COVID-19 and unrecorded vaccinations introduce some uncertainty into the results.

Professor Paul Harrison, Department of Psychiatry, University of Oxford, and Theme Lead, NIHR Oxford Health Biomedical Research Centre, who headed the study, said: ‘It is good news that the excess of depression and anxiety diagnoses after COVID-19 is short-lived, and that it is not observed in children. However, it is worrying that some other disorders, such as dementia and seizures, continue to be more likely diagnosed after COVID-19, even two years later. It also appears that omicron, although less severe in the acute illness, is followed by comparable rates of these diagnoses.’

Dr Max Taquet, NIHR Academic Clinical Fellow, University of Oxford, who led the analyses, said: ‘The findings shed new light on the longer-term mental and brain health consequences for people following COVID-19 infection. The results have implications for patients and health services and highlight the need for more research to understand why this happens after COVID-19, and what can be done to prevent these disorders from occurring, or treat them when they do.’

Funding: NIHR Oxford Health Biomedical Research Centre and MQ Mental Health Research/Wolfson Foundation.

Notes to Editor:

  • The new paper, ‘Neurological and psychiatric risk trajectories after SARS-CoV-2 infection: an analysis of 2-year retrospective cohort studies including 1,284,437 patients’ can be read in The Lancet Psychiatry: https://www.thelancet.com/journals/lanpsy/article/PIIS2215-0366(22)00260-7/fulltext
  • Oxford Health NHS Foundation Trust (OHFT) provides physical, mental health and social care for people of all ages across Oxfordshire, Buckinghamshire, Swindon, Wiltshire, Bath and North East Somerset. Our services are delivered at community bases, hospitals, clinics and people’s homes. We focus on delivering care as close to home as possible.
    As a leading teaching, training and research trust, we have close links to Oxford and Oxford Brookes, Buckinghamshire, Reading and Bath universities. We are part of the Oxford Academic Health Science Centre, working closely with our university colleagues to translate their findings into clinical care as quickly as possible, enabling people using our services to benefit from the latest advances in healthcare. We host the NIHR Oxford Health Biomedical Research Centre with Oxford University, and aim to bring the best science to the complex problems of mental disorders and dementia. We also host the NIHR Applied Research Collaboration Oxford and Thames Valley; a partnership between universities, healthcare, charities and industry, that aims, through applied health research, to co-produce better, more equitable, appropriate and sustainable health and care across the region. www.oxfordhealth.nhs.uk
  • National Institute for Health and Care Research (NIHR)
    The mission of the National Institute for Health and Care Research (NIHR) is to improve the health and wealth of the nation through research. We do this by:
  • Funding high quality, timely research that benefits the NHS, public health and social care;
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  • Attracting, training and supporting the best researchers to tackle complex health and social care challenges;
  • Collaborating with other public funders, charities and industry to help shape a cohesive and globally competitive research system;
  • Funding applied global health research and training to meet the needs of the poorest people in low and middle income countries.

NIHR is funded by the Department of Health and Social Care. Its work in low and middle income countries is principally funded through UK Aid from the UK government.

To find out more please visit www.mqmentalhealth.org.

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