Association between mood disorders and BMI/overweight using a family study approach

Abstract

Background: We previously demonstrated the specificity of familial transmission of the atypical subtype of depression, primarily characterized by overeating and oversleeping. However, the specific components of this subtype that are familial have not been established. The aim of this paper is to examine whether the familial specificity of atypical depression can be attributed to the association between Body Mass Index (BMI) and overweight/obesity with mood disorders.

Methods: The sample included 293 probands recruited from the community and their 544 adult first-degree relatives. Diagnostic assignment was based on a direct semi-structured interview. Mixed effect models were employed to test the familial aggregation and the familial cross-aggregation of mood disorders and BMI/overweight.

Results: There were significant within-individual associations between overweight and the atypical subtype of depression (p-value = 0.003). There was also an association for BMI/overweight between probands and relatives (β = 0.23, p-value < 0.001; odds ratio [OR] = 1.57, 95% confidence interval [CI] = 1.02-2.43, respectively). Atypical depression in probands was significantly associated with BMI and overweight in relatives (β = 0.001, p-value = 0.040; OR = 2.79, 95%CI = 1.20-6.49, respectively).

Limitations: The cross-sectional design impedes our ability to evaluate the direction of these associations. Other potential risk factors, such as diabetes, physical activity and unhealthy diet were not considered.

Conclusions: These findings imply that overweight may be either a precursor or consequence of atypical depression rather than a manifestation of a common diathesis underlying depression in families. Clinicians should pay particular attention to this subtype that could be at increased risk for the development of cardiovascular risk factors and diseases.

Trial registration: ClinicalTrials.gov NCT00071786.

Keywords: Atypical depression; Familial aggregation; Family study; Mood disorders; Overweight.