Long COVID psychiatric sequelae, biochemical markers & tau protein: A 3-year follow-up study

A significant percentage of COVID-19 survivors experience long-term neuropsychiatric and physical issues. Baseline biochemical parameters may be linked to these psychiatric sequelae.

This study aimed to explore the association between baseline biochemical parameters and psychiatric outcomes in COVID-19 survivors three years post-infection.

We enrolled 100 COVID-19 survivors (mild and severe) and conducted comprehensive biochemical, endocrine, and psychiatric evaluations using peripheral blood samples and psychological assessments (GAD-7, PHQ-9, MoCA, ISI) at 3 years of follow-up assessment. Tau protein levels were measured at follow-up. Baseline biochemical data were retrieved from medical records, and linear regression analysis was used to identify predictors of psychiatric symptoms.

HbA1c levels were significantly higher in severe cases at baseline (7.08±2.11 vs. 6.22±1.62) and follow-up (6.54±2.01 vs. 5.78±1.07). Severe cases also had elevated p-tau protein levels (99.34±120 vs. 59.7 ± 45.9). Low sodium and potassium at baseline were negatively correlated with anxiety and depression scores, predicting anxiety (8 %) and depressive symptoms (6 %) in mild cases. Low calcium predicted depressive (10 %) and anxiety symptoms (7.5 %) across all cases.

COVID-19 survivors with a history of severe infection displayed higher p-tau and HbA1c levels, indicating potential new-onset diabetes and neuronal damage. Electrolyte imbalances, particularly sodium, potassium, and calcium, during acute infection predicted long-term psychiatric symptoms, including depression, anxiety, and somatization.