Investigating the relationship between depression, obesity and school performance: using causal inference

Background: Despite the recent emergence of literature establishing the prevalence of childhood depression, research has failed to provide insight in its concomitant factors. While depression in adults has been associated with... [ view full abstract ]

Background: Despite the recent emergence of literature establishing the prevalence of childhood depression, research has failed to provide insight in its concomitant factors. While depression in adults has been associated with multiple negative correlates such as rumination, loss of interest in pleasurable activities, overeating, and lack of concentration, the picture for children is less clear. There is a suggestion that urban disadvantaged children may be more at risk of depression and that obesity and school performance play a role in it, but how these variables interrelate is uncertain. The present study aims to address this issue using a model of causality.
Aims: The aim of the study is to investigate the relationship between depression and obesity among disadvantaged children.
Methods: This study makes use of an observational cross-sectional design. The sample was accessed through an existing health promotion programme which consisted of 604 children at baseline in 2009. The intervention ended in 2012 and it was reported that the intervention had no significant impact on the children. Data for the current study was collected in 2013, recruiting 274 children from the sample, of which only 52 were participants had taken part in the health promotion intervention. It was noted that there were no changes in the health status of those participants over time. Data collected included Body Mass Index (BMI), Child Depression Inventory, indicators of wellbeing, dietary patterns, physical activity, and indicators of school performance. A method of matching known as genetic matching and linear regressions were conducted to make causal inferences. This study received ethical approval from the researcher’s university.
Results: Linear regressions reported statistically significant causal relationship between depression and obesity. The nature of the relationship was bidirectional, depression as treatment (B = .216, p = .027, 95% CI = .209 – 3.310), and obesity as treatment (B = 4.567, p = .003, 95% CI = 1.53 - 7.61).
Conclusion: The findings suggest a bidirectional causal relationship between depression and obesity. The implications of this association need to be incorporated in the implementation of future health promotion interventions and within community health practice.