Mood symptoms, cognitive function, and changes of brain hemodynamics in patients with COVID-19: A functional...

Many patients with coronavirus disease 2019 (COVID-19) may experience emotional issues and cognitive impairment. However, it remains unclear whether the brain mediates the impact of COVID-19 on the emergence of psychopathological symptoms. It remains unclear whether anxiety and depression are caused by stressors or viral infection.

To use functional near-infrared spectroscopy (fNIRS) to detect cortical hemodynamic changes in patients with COVID-19 and their relationship with mental symptoms (mainly depression and anxiety), to investigate whether COVID-19 causes these changes by affecting brain function.

A total of 58 subjects, comprising 29 patients with first acute COVID-19 infection and 29 healthy controls without COVID-19 infection and without anxiety or depression were recruited. Then cortical activation during the performance of the verbal fluency test (VFT) and brain connectivity during the resting state (rs) were evaluated by 53-channel fNIRS. For the COVID-19-infected group, Patient Health Questionnaire-9 (PHQ-9) and General Anxiety Disorder-7 (GAD-7) were used to assess the emotional state before fNIRS measures.

For the rs, compared to the uninfected group, the infected group exhibited lower rs functional connectivity (FC) in the dorsolateral prefrontal cortex (DLPFC), which was correlated with both the PHQ score and GAD score. During the VFT, the infected group exhibited significantly lower cortical activation than the uninfected group in both Broca-left and Broca-right. Besides, the integral value in the DLPFC-L showed a significant negative correlation with the PHQ-9 score during the VFT in the infected group.

There were significant differences in the bilateral Broca area and DLPFC between the COVID-19-infected and uninfected groups, which may be the reason why COVID-19 infection impairs cognitive function and language function and leads to psychiatric symptoms. In addition, the rsFC in patients with COVID-19 was positively correlated with the severity of depression and anxiety, which may be related to the fact that the mental symptoms of patients with COVID-19 are characterized by depression and anxiety, rather than depression or anxiety alone. Our study provides evidence that the psychological and emotional issues caused by COVID-19 are not only due to external social factors but also involve more direct brain neural mechanisms and abnormal neural circuits, which also provide insights into the future treatment and prognosis of individuals with COVID-19.