Background. The COVID-19 pandemic and related restrictions, like lockdowns, have resulted in changes in the lives of adolescents. Not much was known about the effect of lockdowns on social anxiety...Show moreBackground. The COVID-19 pandemic and related restrictions, like lockdowns, have resulted in changes in the lives of adolescents. Not much was known about the effect of lockdowns on social anxiety in adolescents. Aim. This study aimed to gain insight into changes in social anxiety before and after a school closure associated with COVID-19 lockdown and its relation to the experience of the lockdown in Dutch adolescents aged 12-15 years. Methods. A total of 188 adolescents (M = 13.48, SD = 0.81) completed self-report measures of social anxiety on March 2020 (T1). In September 2020 (T2) they completed the same self-report measures of social anxiety, enjoyment of the lockdown, and Worries about COVID-19. Results. Adolescents with average or high symptoms of social anxiety before the first school closure showed a significant reduction in social anxiety symptoms after the first school closure. The expected positive association between social anxiety before and after school closure was moderated by Enjoying the lockdown but not gender. Furthermore, higher symptoms of social anxiety before the first school closure were associated with higher levels of enjoying the lockdown. Conclusion. Results indicated that adolescents with moderate to high social anxiety symptoms and who enjoyed the lockdown and associated consequences such as less face-to-face interaction were most at-risk of reporting higher symptoms of social anxiety once the schools had reopened.Show less