Validating the questionnaire of achievement of developmental task (QADT) to measure achieving mental wellness in school-aged children.

Introduction: This article presents a verification of the factor structure and validation of the Questionnaire of Achievement of Developmental Task (QADT), designed to measure children's social expectations in early childhood. Three tasks, important from the point of view of both children's functioning at a given life stage and preparation for the next developmental phase, were selected. These are school skills, cooperation with others and a sense of competence. The research aimed to verify the tool's psychometric validity and establish relationships between developmental tasks and indicators of children's mental health. Method: The study was conducted in primary school's 4th, 5th and 6th grades ( Results: The tool shows sufficient validity and reliability. The hypothesis regarding associations between the level of developmental task completion and life satisfaction and depressive symptoms was also confirmed. Conclusions: The QADT tool can be used in scientific research. This work contributes to the growing body of literature on factors influencing children's mental health and underscores the importance of measuring social expectations of children in early childhood. It also highlights the need to consider developmental tasks in clinical practice and interventions to improve children's mental health. Ultimately, the findings of this study can inform the development of effective preventive and intervention strategies to promote children's mental health and well-being.