Body Mass Index and Depressive Symptoms: Testing for Adverse and Protective Associations in Two Twin Cohort Studies

Abstract

Studies have suggested both adverse and protective associations of obesity with depressive symptoms. We examined the contribution of environmental and heritable factors in this association. Participants were same-sex twin pairs from two population-based twin cohort studies, the Older Finnish Twin Cohort (n = 8,215; mean age = 44.1) and the US Midlife Development in the United States (MIDUS; n = 1,105; mean age = 45.1). Body mass index (BMI) was calculated from self-reported height and weight. Depressive symptoms were assessed using Beck's Depression Inventory (BDI; Finnish Twin Cohort), and by negative and positive affect scales (MIDUS). In the Finnish Twin Cohort, higher BMI was associated with higher depressive symptoms in monozygotic (MZ) twins (B = 2.01, 95% CI = 1.0, 3.0) and dizygotic (DZ) twins (B = 1.17, 0.5, 1.9) with BMI >22. This association was observed in within-pair analysis in DZ twins (B = 1.47, CI = 0.4, 2.6) but not in within-pair analysis of MZ twins (B = 0.03, CI = -1.9, 2.0). Consistent with the latter result, a bivariate genetic model indicated that the association between higher BMI and higher depressive symptoms was largely mediated by genetic factors. The results of twin-pair analysis and bivariate genetic model were replicated in the MIDUS sample. These findings suggest an association between obesity and higher depressive symptoms, which is largely explained by shared heritable biological mechanisms.

Maternal early pregnancy obesity and depressive symptoms during and after pregnancy

“…Genetic and epigenetic factors may also underlie the associations between obesity and depression. Twin studies suggest that the genetic component of depression is partially shared with obesity (Afari et al 2010; Jokela et al 2016). According to a recent systematic review of genome-wide association and candidate gene studies pleiotropic genes, such as the FTO gene, may underlie (Amare et al 2017), but findings are however, inconsistent (Walter et al 2015).…”

Sustained Obesity and Depressive Symptoms over 6 Years: Race by Gender Differences in the Health and Retirement Study

“…Despite the well-established links between multiple health problems such as BMI, SRH, physical activity, and depressive symptoms (Okosun et al, 2001; Stunkard et al, 2003; Jokela et al, 2016; Romo-Perez et al, 2016), little is known about race by gender differences in the links between sustained health problems over time. The current study aimed to test if sustained high depressive symptoms and poor SRH similarly reflect sustained high BMI and physical inactivity in Black men and women and White men and women, using a nationally representative cohort of U.S. adults over age of 50.…”

The Genetic Basis of Future Pharmacological Strategies for the Management of Comorbid Obesity and Depression: A Scoping Review

“…Evidence from family, twin, linkage, candidate gene and genome-wide association studies suggests that genetic factors account for a significant proportion of the overlap between depression and obesity [23][24][25][26][27]. Besides contributing substantially to the shared biological substrate of these disorders [28], multiple genetic variants influence the occurrence of specific symptoms, such as increases in appetite, during episodes of depression [29,30].…”