Participants will undergo two positron emission tomography (PET) scans: one [18F]FEPPA scan (for translocator protein (TSPO)) and one [11C]SL25.1188 scan (for monoamine oxidase B (MAO-B)) - as well as one magnetic resonance imaging (MRI) scan.~The primary hypotheses are:~TSPO total distribution volume (TSPO VT) and MAO-B total distribution volume (MAO-B VT) are greater in the prefrontal cortex (PFC), anterior cingulate cortex (ACC), and hippocampus in COVID-19 with new onset, persistent major depressive episode (MDE) with or without other neuropsychiatric symptoms after recovery from mild respiratory symptoms (DNP-mild).~TSPO VT and MAO-B VT are greater in the PFC, ACC, and hippocampus in COVID-19 with new onset, persistent MDE with or without other persistent neuropsychiatric symptoms after recovery from moderate respiratory symptoms (DNP-moderate).~Exploratory hypotheses are:~Greater TSPO VT and MAO-B VT in the PFC, ACC, and hippocampus will be positively associated with severity of MDE symptoms and poorer performance on cognitive tasks.~TSPO VT and MAO-B VT will be positively correlated in the PFC, ACC and hippocampus in COVID-DNP.
The purpose of this study is to use state of the art brain imaging technology to investigate neuroinflammation in participants with depression after the respiratory symptoms of coronavirus disease 2019 (COVID-19) have passed.