OBJECTIVES: The coronavirus disease 2019 (COVID-19) pandemic had direct effects on population health through infection and morbidity, as well as indirect effects on population mental health. We estimated the network structure of post-traumatic stress symptoms (PTSS) and depressive symptoms throughout the pandemic in Korea and aimed to identify the most central and bridging symptoms. METHODS: Participants aged 30–64 years completed mental health surveys across 3 phases of the COVID-19 pandemic: March 2020 (n=1,925), February–March 2021 (n=1,754), and December 2021–January 2022 (n=1,595). Using PTSS and depressive symptom data, we conducted network analyses, and the primary measures of symptom importance (centrality) were expected influence and bridge expected influence. RESULTS: In the comorbidity network, although the most central symptoms fluctuated over the course of the pandemic, sleep problems were consistently identified as the most influential bridge symptoms throughout. The symptom network structure differed between the subacute and chronic phases of the pandemic. CONCLUSIONS We found evidence of changes in the network structure of PTSS and depressive symptoms, even as sleep problems retained a consistent role as a bridging symptom. Although overall network structures varied across phases of the pandemic, the bridging role of sleep-related symptoms remained consistently strong, suggesting that sleep problems may represent a general and enduring mechanism underlying PTSS–depression comorbidity. During future pandemics, prompt screening for sleep problems may help prevent the development of comorbidity between PTSS and depressive symptoms.

Nutcracker syndrome is caused by external compression of the left renal vein and is characterized by various symptoms, such as hematuria and left flank pain. However, long-standing gross hematuria is uncommon. We report the case of a 23-year-old woman who had had painless gross hematuria for several months. Kidney biopsy revealed thin basement membrane disease, but this did not explain the gross hematuria with proteinuria. Renal venography and Doppler ultrasonography showed increased diameter and velocity ratios between the left renal vein and inferior vena cava. Cystoscopy revealed that the hematuria originated from the left ureteral orifice. These results indicate coexisting Nutcracker syndrome. Nutcracker syndrome with thin basement membrane disease should be considered in the differential diagnosis of a patient who has long-standing gross hematuria.