3. 1 General characteristics of the sample and compliance with lockdown
The sample included 8426 people. The majority of participants were female (70.53%, n = 5943), with a median age of 21 years old (IQR: 19.00, 25.00), reported living in urban areas (70.73%, n = 5960), not consuming sleep pills (97.70%, n = 8232), and not having a partner (81.60%, n = 6876). While the majority were university students (83.91%, n = 7070), some reported having a job (10.69%, n = 901) and few were unemployed (5.40%, n = 455).
Mandatory lockdown due to the pandemic had a profound effect on the mobility of the population. Between May and June 2020 mobility in general was reduced by near 50% in comparison to January – February of the same year. Mobility to transit stations (-52.93, SD 7.71), to retail and recreation (-47.22, SD 19.87), and to parks (-46.44, SD 8.67) experienced higher reduction in comparison to mobility to workplaces (-39.83, SD 12.76) and to groceries and pharmacies (-29.75, SD12.00). In contrast, staying at home increased by 23.71 (SD 3.20).
3.2 Sense of coherence, depression and sleep quality
Median SOC – 15 score of the sample was 61 (IQR: 55.00, 67.00) with a minimum and maximum of 15.00 and 75, respectively. A high (n = 2961, 35.14%) or very high (n = 4944, 58.68%) sense of coherence was reported by nearly 94% of individuals, the remaining 6% reported low (n = 487, 5.78%) or very low (n = 34, 0.40%) sense of coherence. Median PHQ-9 score of the sample was 3 (IQR: 1.00, 7.00) with a minimum and maximum of 0.00 and 27, respectively. Symptoms of mild to moderate depression were reported by nearly 36% of the individuals (mild: 27.20%, n = 2292; moderate: 9.23%, n = 778). Symptoms of moderate/severe to severe depression were reported by nearly 6% of participants (moderate/sever: 3.96%, n = 334; sever: 1.95%, n = 164). Median PSQI of the sample was 4 (IQR: 2.00, 7.00) with a minimum and maximum of 0.00 and 17. respectively. Bad quality of sleep was reported by nearly 38.52% (n = 3246) of participants. A summary of SOC-15, PHQ-9, PSQI and corresponding groups given by respective cut-off points by biological sex is depicted in Table 1.
3.3 Resilience and depression in the context of the lockdown
An inverse non-linear relationship was found between depression and sense of coherence (F = 13.79, p < 0.001). As it is shown in Fig. 1 higher scores of PHQ-9 were associated with lower SOC-15 scores, suggesting that depression is associated with lower resilience. We also found that restriction of mobility was associated with depression. In this way, a longest stay at home was related with higher scores of PHQ-9 (F = 10.35, p = 0.001; Fig. 1, panel a). Similarly, a higher restriction of mobility towards groceries and pharmacies was related to higher scores of PHQ-9 (F = 5.85, p = 0.016; Fig. 1, panel b). Depression was not associated with restriction of mobility because of retail and recreation (F = 1.25, p = 0.263).
3.4 Resilience and sleep quality in the context of lockdown
An inverse non-linear relationship was found between quality of sleep and sense of coherence (F = 13.63, p < 0.001). As it is shown in Fig. 2 higher scores of PSQI were associated with lower SOC-15 scores, suggesting that bad sleep quality is associated with lower resilience. In contrast to depression, sleep quality was not significantly associated to time spend at residential places (F = 0.41, p = 0.524), neither to mobility towards groceries and pharmacies (F = 0.84, p = 0.358) or retail and recreation (F = 0.01, p = 0.905).
3.5 Depression and sleep quality and covariates
Depression was significantly associated with age (F = 4.21, p = 0.040), sex (F = 76.64, p < 0.001), area of residence (F = 6.98, p = 0.008), and consumption of sleeping pills (F = 113.59, p < 0.001), but not with living with a partner (F = 1.94, p = 0.164), occupation (F = 1.10, p = 0.334) or persons living at home (F = 1.00, p = 0.391). In this way, older people, females, people living in urban areas, and who consumed sleeping pills showed higher PHQ-9 values. Similarly, sleep quality was significantly associated with age (F = 22.55, p < 0.001), sex (F = 5.33, p = 0.021), area of residence (F = 37.80, p < 0.001), consumption of sleeping pills (F = 131.93, p < 0.001), and living with a partner (F = 11.90, p = 0.001), but with occupation (F = 0.44, p = 0.646) or persons living at home (F = 2.36, p = 0.069). In this way, older people, females, people living in urban areas, who consumed sleeping pills or lived with less people showed higher PSQI values.