**3. Results**

#### *3.1. Country Differences in Depression and Anxiety*

A one-way between subjects ANOVA was conducted to compare the effect of country on depression and anxiety (see Figures 1 and 2, for more details). There was a significant effect of country on depression with a large effect size, *F*(8, 2340) = 31.02, *p* < 0.001, ηp<sup>2</sup> = 0.09. Post hoc comparisons using the Tukey HSD test indicated that the mean score of the PHQ-8 in Poland was significantly higher than in Slovenia (*p* < 0.01), Czechia (*p* < 0.001), Ukraine (*p* < 0.001), and Germany (*p* < 0.05), and was significantly lower than in Turkey (*p* < 0.001). In addition, Slovenia demonstrated higher depression than Czechia (*p* < 0.01), but lower than Turkey (*p* < 0.001) and Colombia (*p* < 0.05). Among all of the nine countries, the lowest scores in depression emerged in Czechia, where it was significantly lower than that of Russia (*p* < 0.001), Germany (*p* < 0.001), Turkey (*p* < 0.001), Israel (*p* < 0.001), and Colombia (*p* < 0.001). Depression in Ukraine was found as being significantly lower than in Russia (*p* < 0.05), Turkey (*p* < 0.001), and Colombia (*p* < 0.001). Turkey scored the highest in depression, when compared to other countries, including Russia (*p* < 0.001), Germany (*p* < 0.001), Israel (*p* < 0.001), and Colombia (*p* < 0.01). The mean scores for depression are shown in Figure 1.

**Figure 1.** Mean scores of depression (PHQ-8) among university students across the nine countries during the first wave of the COVID-19 pandemic. The dots in the figure represent outliers.

**Figure 2.** Mean scores for anxiety (GAD-7) among university students across the nine countries during the first wave of the COVID-19 pandemic. The dots in the figure represent outliers.

A significant effect of country on anxiety was also revealed, with a large effect size, *F*(8, 2340) = 57.78, *p* < 0.001, ηp<sup>2</sup> = 0.15. As Tukey's HSD test indicates, the mean score of the GAD-7 in Poland was significantly higher than in Slovenia (*p* < 0.01), Czechia (*p* < 0.001), Ukraine (*p* < 0.001), Russia (*p* < 0.01), and Germany (*p* < 0.001). Slovenia showed significantly higher scores in anxiety than Czechia (*p* < 0.001) and Germany (*p* < 0.001), and lower than Turkey (*p* < 0.001). Czechia demonstrated significantly lower anxiety than Ukraine (*p* < 0.05), Russia (*p* < 0.001), Turkey (*p* < 0.001), Israel (*p* < 0.001), and Colombia (*p* < 0.001), and significantly higher anxiety than Germany (*p* < 0.001). Anxiety level in Ukraine was found as being significantly lower than in Russia (*p* < 0.05), Turkey (*p* < 0.001), Israel (*p* < 0.01), and Colombia (*p* < 0.001), and higher than in Germany (*p* < 0.01). As far as anxiety is concerned, Russia significantly differed from Germany (*p* < 0.001) and Turkey (*p* < 0.01). Among the nine countries, Germany showed the lowest scores in anxiety, significantly lower than Turkey (*p* < 0.001), Israel (*p* < 0.001), and Colombia (*p* < 0.001). In contrast, Turkey demonstrated the highest anxiety, significantly higher than Israel (*p* < 0.001), and Colombia (*p* < 0.01). The mean scores of anxiety are shown in Figure 2.
