Weight change in depression: influence of "disinhibition" is mediated by body mass and other variables.

The direction of weight change (gain or loss) in depression has recently been found to be a stable characteristic of patients across depressive episodes. A search for determinants of the direction of weight change revealed two candidates: the body mass index (BMI) (weight in kilograms/height in meters squared) and a psychological variable, "disinhibition" of dietary restraint. The present study, of 68 patients with a history of recurrent depression, found a significant correlation between BMI and weight change; in other words, heavier persons were more likely to gain weight if depressed. There was also a correlation between "disinhibition" and weight change. "Disinhibition" correlated with BMI and, when controlled for BMI, age and sex, the correlation between "disinhibition" and weight change fell to insignificance. We conclude that BMI along with age and sex mediated the correlation between "disinhibition" and weight change.