Having symptoms of COVID-19 infection is associated with poorer mental health and lower life satisfaction, according to a study published in The Lancet Psychiatry journal.

The team, led by researchers at King's College London and University College London (UCL) in the UK, looked at the impact of COVID-19 infection on subsequent mental health and wellbeing.

Data was taken from 11 longitudinal studies between April 2020 and April 2021, in which there were 54,442 participants with and without self-reported COVID-19. Researchers found that rises in psychological distress, depression, anxiety, and lower life satisfaction were associated with prior self-reported COVID-19.

The associations with poorer mental health did not lessen over time after infection, highlighting the potential enduring impacts of the disease and the need for a longer follow-up process from healthcare providers.

Self-reported COVID-19 was consistently associated with psychological distress, regardless of whether people tested positive for antibodies to the virus.

These effects of infection were felt similarly in different groups of gender, ethnicity and socio-economic circumstances.

The study suggests that the infection of COVID-19 might impact mental health most in older people as people with self-reported infection aged 50 years and older showed a stronger association with poorer mental health.

This might reflect that older people are more likely to experience more severe COVID-19 symptoms, greater worry around infection, and increased risk of blood vessel (microvascular) or brain (neurological) changes after infection, the researchers said.

This contrasts to the effect of the pandemic overall on mental health, where previous studies have shown that women and adults aged 25-44 have had the greatest adverse impacts, they said.

"These findings suggest that there were prolonged mental health consequences of COVID-19 infection for some people at the beginning of this pandemic," said study joint first author Ellen Thompson from King's College London.

"Understanding why this is the case will be key to finding treatment strategies for those affected as well as preventing such effects in future pandemic waves," Thompson said.

The study brings together many of the UK's longitudinal studies to provide a comprehensive overview of the impacts of COVID-19 infection on population mental health.

"Compared to most studies to-date that have focussed on more severe and hospitalised cases, this study demonstrates the impact of infection during a pandemic on overall population mental health and wellbeing," said study senior author Professor Praveetha Patalay from UCL.