Comorbidity
Income inequality and comorbid overweight/obesity and depression among a large sample of Canadian secondary school students: The mediator effect of social cohesion Jason Mulimba Were* Jason Were Stephen Hunter Karen A. Patte Scott T. Leatherdale Roman Pabayo
Background: Comorbid overweight/obesity (OWO) and depression is emerging as a public health problem among adolescents. Income inequality in a community is a structural determinant of health that independently increases the risk of both OWO and depression among youth. However, no study has examined the association between income inequality and comorbid OWO and depression or tested potential mechanisms in the relationship.
Objectives: 1) To identify the association between income inequality and comorbid OWO and depression; and 2) To test whether social cohesion mediates this relationship.
Methods: We used data from the 2018-2019 Cannabis, Obesity, Mental health, Physical activity, Alcohol, Smoking and Sedentary behavior (COMPASS) project. Our sample was composed of 46,171 adolescents from 136 schools distributed in 43 census divisions in 4 provinces in Canada (BC, AB, ON, QC). Comorbidity was determined by a participant being simultaneously classified as having OWO (BMI-Z > 1) and depression (≥10 points on the 10-item Center for Epidemiologic Studies Depression scale Revised). Income inequality was measured using the Gini coefficient at the census division level for school postal codes. Social cohesion was assessed using a school connectedness scale. Sex-stratified multilevel path analyses models were used to examine the study objectives.
Results: The direct effect between income inequality and OWO-depression comorbidity was not significant (Figure 1). However, income inequality was significantly associated with increased risk of comorbidity via social cohesion. One standard deviation increase in the Gini coefficient was associated with a 9% and 8% increase in the odds of comorbidity in girls (OR=1.09; 95% CI = 1.03, 1.15) and boys (OR=1.08; 95% CI = 1.03, 1.13), respectively.
Conclusion: Policies aimed at reducing income inequality, and interventions to improve social cohesion, may contribute to reducing the risk of OWO-depression comorbidity among adolescents.
