Introduction
There has been growing concern about the long-term effects of COVID-19 on mental health. The biological factors common to psychiatric conditions and COVID-19 are not yet fully understood.

Methodology
We narratively reviewed prospective longitudinal studies that measured metabolic or inflammatory markers and assessed psychiatric sequalae and cognitive impairment in individuals with COVID-19 at least 3 months after the infection. A literature search identified three relevant cohort studies.

Results
Overall, depressive symptomatology and cognitive deficits persisted for up to one year after COVID-19; depression and cognitive changes were predicted by acute inflammatory markers, and changes in these markers correlated with changes in depressive symptomatology; female sex, obesity, and the presence of inflammatory markers were associated with more severe clusters of physical and mental health status in patients’ self-perceived recovery; and plasma metabolic profiles of patients continued to differ from those of healthy controls three months after hospital discharge, which were associated with widespread alterations in neuroimaging, reflecting issues with white matter integrity. This is a non-systematic review and cautions should be made while interpreting the conclusions.

Conclusion
In individuals affected by the COVID-19, prolonged exposure to stress and alterations in metabolic and inflammatory markers plays a central role in psychiatric sequalae and cognitive deficits in the long term.