Depression is a common symptom after many long or difficult illnesses, perhaps especially respiratory and cardiovascular ones. https://www.ncbi.nlm.nih.gov/pmc

Depression is a common symptom after many long or difficult illnesses, perhaps especially respiratory and cardiovascular ones. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7418220/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7418220/ https://link.springer.com/article/10.1186/s13054-018-2223-6 https://link.springer.com/article/10.1186/s13054-018-2223-6 https://www.cambridge.org/core/journals/the-british-journal-of-psychiatry/article/abs/prevalence-of-depression-after-stroke-the-perth-community-stroke-study/8699FFD5D7F073FBBA2DD370DB11FE78 https://www.cambridge.org/core/journals/the-british-journal-... There is good evidence now that severe covid (early variants at least) causes atrophy of gray matter in a variety of regions, causing, e.g. loss of smell. Not sure if this is specific to covid however.