LAUSR

Abstract Introduction Given that coronavirus disease 2019 (COVID‐19) has largely influenced adolescents' physical and mental health around the globe, it is important to identify protective factors that may promote adolescents' positive adjustment during the pandemic. This study aimed to examine the role of parental attachment and COVID‐19 communication in adolescents' health behavior and mental health during COVID‐19. Methods A total of 442 Chinese parent−adolescent dyads (mean age of adolescents = 13.35 years; 50% girls) completed two‐wave longitudinal surveys over the span of 2 months during the pandemic (Wave 1: July 2020; Wave 2: September 2020). At each wave, adolescents reported on their COVID‐19‐related health behavior, general health behavior, depressive symptoms, and anxiety symptoms. At Wave 1, parent−adolescent attachment security and COVID‐19 communication were also assessed. Results Adolescents' attachment security to parents was associated with their increased COVID‐19‐related and general health behavior as well as decreased depression and anxiety over 2 months during COVID‐19. Moreover, more frequent parent−adolescent COVID‐19 communication was associated with adolescents' increased COVID‐19‐related and general health behavior over time. Notably, attachment security's and COVID‐19 communication's associations with health behavior largely remained the same after taking into account both factors simultaneously. In addition, results from exploratory analyses suggest that more frequent COVID‐19 communication mediates the link between attachment security and increased health behavior. Conclusions These findings highlight the importance of promoting attachment security and COVID‐19 communication between parents and adolescents during the pandemic, which may play a positive role in adolescents' health behavior and mental health.