CRP and major depressive disorder: Significantly higher CRP levels (difference 1.6; 95% confidence interval 0.18 to 3.76; Mann–Whitney U test, p = 0.02) and depression levels (difference −5; confidence interval −7 to −2; Mann–Whitney U test, p = 0.00) were observed in participants who were bad sleepers according to the PSQI compared with good sleepers (Table 7).