Cross-Cohort Changes in Parent-Rated Child Mental Health over Two Decades

   Background: research on time trends in child mental health is needed to clarify the effects of the COVID-19 pandemic, and to predict later developmental pathways. However, the results obtained in different countries may be relatively culture specific.   The aim was to compare levels of child mental health in three comparable cohorts assessed with identical measures before and during the COVID-19 pandemic, taking age, gender and family sociodemographic characteristics into account.   Participants and methods:: three cohorts of 2–14-year-old children from a large Siberian city were compared: 1436 (52 % boys) assessed in 2001–2004, 1508 (49 % boys) assessed in 2014–2017 and 1276 (52 % boys) assessed in 2020–2021. Parents completed the Strengths and Difficulties Questionnaire designed for a quantitative assessment of child and adolescent psychiatric problems and prosocial behaviour. Linear regression analyses examined cross-cohort changes by age and gender controlling for family composition, parental education and occupation.   Results: from 2001 to 2021, levels of child psychiatric problems and their impact on daily functioning decreased, whereas levels of prosocial behaviour increased. During the COVID-19 pandemic, there was an increase in levels of emotional symptoms and conduct problems and a decrease in levels of prosocial behaviour compared to the prepandemic period. Time trends in child mental health were similar for both boys and girls of different ages and did not depend on family composition or parental education and occupation.   Conclusions: over 20 years, there were positive trends in child mental health; however, psychosocial stress during the pandemic was accompanied by negative changes. Further studies will need to clarify possible determinants of secular trends in Russian child mental health and different developmental pathways.