%0 Journal Article
%T Depression and body mass index, a u-shaped association
%A Leonore M de Wit
%A Annemieke van Straten
%A Marieke van Herten
%A Brenda WJH Penninx
%A Pim Cuijpers
%J BMC Public Health
%D 2009
%I BioMed Central
%R 10.1186/1471-2458-9-14
%X We investigated the existence of such a U-curve in a sample of 43,534 individuals, aged between 18¨C90 years, who participated in a cross-sectional study (Continuous Survey of Living Conditions) of physical and mental health in the general population of the Netherlands. We calculated linear and nonlinear (quadratic) ANOVA with polynomial contrast and curve fit regression statistics to investigate whether there was a U-shaped trend in the association between BMI and depression.We find a very significant U-shaped association between BMI categories (underweight, normal, overweight and obesity) and depression (p ¡Ü 0.001). There is a trend indicating a significant difference in the association between males and females (p = 0.05). We find a very significant U-shaped (quadratic) association between BMI (BMI2) and depression (p ¡Ü 0.001), continuous BMI is not linearly associated with depression (p = 0.514).The results of this study give evidence for a significant U-shaped trend in the association between BMI and depression.In recent decades, the association between obesity and depression has been examined in a considerable number of studies [1,2]. Both conditions are associated with increased risk of disability, reduced quality of life, increased mortality and co morbid conditions such as cancer, diabetes and coronary heart disease. The prevalence of both obesity and depression is very high, and both are associated with an enormous individual burden and huge economic costs [3].Weight gain is for the most part influenced by decreased physical activity and increased intake of calorie-dense food. The development of obesity depends on genetic, metabolic and environmental factors [1,4]. Depression is caused by a combination of biological, psychological and social factors, and most researchers support vulnerability-stress models. In these models the development of a depressive disorder is triggered when a vulnerable (psychological and/or biological) individual experiences a life
%U http://www.biomedcentral.com/1471-2458/9/14