Which Came First - the Depression or the Weight Gain?
A new study investigated whether, over time, obesity is associated with change in depressive symptoms or if baseline symptoms of depression are associated with change in body mass index (BMI) and waist circumference. Using latent growth curve modeling to examine data from years 5, 10, 15, and 20 of the Coronary Artery Risk Development in Young Adults study, researchers assessed depressive symptoms with the Center for Epidemiological Studies Depression scale. People who reported symptoms of depression, like feeling sad or hopeless, gained weight more rapidly over a 15-year period and accrued more belly fat than those who appeared to be happier. Those who were obese initially may have been depressed but did not become more depressed over time.
Depression can cause fatigue and lead to inactivity and increased food consumption. Researchers say there could be some third underlying factor that is actually causing both the depression and the obesity. Chronic stress is the mediator chronic stress arousal leads to depressed affect, which then leads to excess weight gain. The stress hormone cortisol, for example, stimulates and promotes fat storage, especially in the abdominal area, since the body has evolved to store calories during times of stress.
Needham BL, Epel ES, Adler NE, Kiefe C. (2010). Trajectories of change in obesity and symptoms of depression: the CARDIA study. American Journal of Public Health. 100(6):1040-6.
