Introduction to the special issue: How COVID-19 has affected students' health, achievement, and mental health.

The worldwide pandemic caused by COVID-19 was an event that has left an indelible mark upon the people who lived through this period. This special issue of is devoted to exploring the wide range of issues that children, families, and schools dealt with during the pandemic. The following topics are discussed: (1) an overview of how children were affected in both physical and psychological terms, (2) the range of problems that professionals working with youth during the pandemic had to address, (3) the special issues that impacted college-age students during the pandemic, and finally (4) the various factors that influenced the level of impact that COVID-19 had on children and their families.