RESUMO
AIM: We wanted to examine the impact of the Covid-19 pandemic on mental health in Danish school children in 5th to 7th grade (11 to 15 years), and whether the impact differed across age and sex. METHODS: We included 793 and 391 school children from winter 2020 and winter 2021, respectively. Mental health was measured using the Short Warwick-Edinburgh Mental Well-Being Scale (SWEMWBS), Strengths and Difficulties Questionnaire (SDQ), and Brief Resilience Scale (BRS). Data were analyzed by sex using linear regression models adjusting for grade (age), cohabitation, geographical region, employment status of parents, and schools as clusters. RESULTS: Girls in 5th grade and boys in 6th grade during Covid-19 had statistically significant lower well-being (SWEMWBS) compared with before Covid-19. Girls in 5th and 6th grade during Covid-19 had non-statistically significant lower scores on all subscales of SDQ compared with girls before Covid-19. Girls in 7th grade during Covid-19 had statistically significant lower total difficulty score (SDQ) and fewer conduct problems (SDQ) compared with girls before Covid-19. Boys in 5th grade during Covid-19 had statistically significant fewer conduct problems (SDQ) compared with boys before Covid-19. CONCLUSIONS: This study indicates that the Covid-19 pandemic impacted Danish school children differently across sex and grade (age). During Covid-19, mental health tended to be better among the oldest girls and worse among the youngest girls compared with girls before Covid-19. Boys in 6th grade had poorer mental well-being, and boys in 5th grade had fewer conduct problems during Covid-19 compared with before Covid-19.