„Across OECD countries, just about two in three students reported that they are satisfied with their lives, and that percentage shrank by five percentage points between 2015 and 2018. Some 6 % of students reported always feeling sad.“
Angel Gurría, OECD-Generalsekretär. In: OECD (Hrsg.), PISA 2018 Results. Are Students Ready to Thrive in an Interconnected World? (2020), S. 3.