The BELLA Study: First Results From the Longitudinal Mental Health Module of the German National Health Interview and Examination Survey Among Children and Adolescents
Aims: The longitudinal BELLA study is the mental health module of the German National Health Interview and Examination Survey among Children and Adolescents and collects comprehensive data on well-being, quality of life and mental health of children and adolescents in Germany since 2003. The BELLA study design allows the analyses of individual developmental trajectories of health-related quality of life and mental health from childhood into adulthood and the investigation of related risk and protective factors. Methods: BELLA examined well-being, quality of life and mental health in a representative sample of families with children aged 7 to 17 years by means of computer-assisted telephone interviews and subsequent questionnaires through self-report and parent-report. Of the 2,863 participants included in the BELLA study at baseline, 2,423 (84.6%) participated in the 1-year follow-up, 2,190 (76.5%) participated in the 2-year follow-up and 1,429 (49.9%) in the 6-years follow up. A total of 1,255 (43.84%) children and adolescents took part at all four BELLA measurement points. The latest follow-up examination (2015-2017) is designed as an online questionnaire and includes the first-time use of the Kids-CAT - a computer-adapted test for health-related quality of life in children and adolescents - in a population based sample. Data analyses include multivariate and longitudinal growth modelling methods. Results: The overall findings demonstrate an overall high level of health-related quality of life. They also indicate a higher likelihood to develop mental health issues between the age of 7 and 12 years and after the age of 19 years. Among all children and adolescents participating at the first four measurement points, about 10% showed clinically significant mental health problems at each measurement point, with a third of the cases at baseline also reporting mental health problems at the 6-year follow-up. Determinants of mental health and health-related quality of life of children and adolescents will be discussed and the latest follow-up examination will be presented. Conclusion: The BELLA study provides important information on young people's well-being, quality of life and mental health in Germany. It highlights the importance of strengthening resources in the personal, familial and social domains as an integral part of prevention and treatment interventions.