Background: While Croatia shared COVID-19 pandemic with other countries, its capital area was also hit by a 5.6 magnitude earthquake. The simultaneous impact of these two disasters on psychiatric patients is largely unknown, and we addressed those knowledge gaps. Methods: The cross-sectional study was conducted during the pandemic’s first peak, in the aftermath of earthquake, by telephonic survey. Measurements included the Patient Health Questionnaire-9, the Perceived Stress Scale and the semi-structured interview to evaluate the impact of pandemic stress and earthquake. Overall 396 patients with depression and/or anxiety disorders (DAD), 229 participants with schizophrenia spectrum disorders (SSD) and 205 healthy controls were enrolled. Results: Both patient groups had higher depression and stress levels than controls, independent of sex, age and the presence of somatic comorbidity. After controlling for the same covariates, patient groups had higher COVID-19- and earthquake-related fears than controls. In patients with DAD, both fears were greater than among SSD patients. When comparing the two fears, the fear from earthquake was higher in DAD and control groups, whereas in SSD patients there was no such difference. Conclusions: Patients with DAD were the most vulnerable group during disasters, while earthquake seems to be associated with more fear than the pandemics, at least in DAD patients and healthy individuals. Future longitudinal studies should determine if early psychological support might alleviate stress levels after disasters and prevent further worsening of mental health, particularly among DAD patients.

Treatment-resistant depression (TRD) remains a challenge despite the growing number of interventions. Peripheral interleukin-6 (IL-6) levels have repeatedly been associated with both the presence and response to different treatments in TRD. There is currently no information available on the effects of bright light therapy (BLT) on serum IL-6 levels. This study assessed the effects of BLT on serum IL-6 levels in TRD patients. Serum IL-6 was determined at two points in TRD patients—at baseline and after 4 weeks of BLT—and at a single point in the healthy controls. Depression severity was measured by the Hamilton Rating Scale for Depression (HAMD)-17 and the Montgomery–Åsberg Depression Rating Scale (MADRS). The study included 104 females, 54 diagnosed with TRD (median age 52.5) and 50 healthy controls (median age 44.5). At baseline, patients had higher IL-6 levels than the controls. BLT treatment reduced HAMD-17 and MADRS scores. Serum IL-6 levels were not significantly affected by the 4 weeks of BLT. However, when patients were divided according to treatment response, IL-6 levels were increased in responders to BLT. The neuroinflammatory mechanism may be involved in the etiopathogenesis and the treatment of TRD, while changes in serum IL-6 levels may be potential indicators of response to treatment.

Brain-derived neurotrophic factor (BDNF) is implicated in the etiology and treatment response in major depressive disorder (MDD). However, peripheral BDNF concentrations have not been compared across different MDD stages. Bright light therapy (BLT) offers some potential in treatment-resistant depression (TRD), but its effects on BDNF levels are unknown. This study included a cross-sectional analysis of plasma BDNF concentration in females with TRD, unmedicated MDD patients, and healthy controls (HC), and measurements of longitudinal BLT effects on plasma BDNF levels in TRD patients. The present study included 55 drug-naïve, first-episode patients, 25 drug-free recurrent-episode MDD patients, 71 HC participants, and 54 TRD patients. Patients were rated by Hamilton Depression Rating Scale (HAMD)-17 and the Montgomery–Åsberg Depression Rating Scale (MADRS). Patients with TRD received BLT during 4 weeks. The total HAMD-17 and MADRS scores decreased following BLT. All patient groups had lower plasma BDNF than HC, but BDNF levels did not differ between first- and recurrent-episode BDNF patients and TRD patients before or after BLT. However, responders and remitters to BLT had higher post-treatment plasma BDNF concentrations than patients who did not achieve response or remission. The changes in plasma BDNF levels may be candidates for biomarkers of treatment response to BLT in TRD patients.