Cognitive Processing of Facial Size and Valence in Depression and Obesity

Abstract

Prior research suggests that obesity is a risk factor for developing depression, but not all obese individuals develop depression; so what are the common factors underlying comorbid obesity and depression that may serve as markers for depression risk? Previous studies have reported the effects of obesity and negative affect on the P300 (P3) component and Thought-Shape Fusion (TSF), but prior to the present study, there has been no exploration of cognitive processing differences or similarities in comorbid depression and obesity. This study investigated if attention bias differences exist between currently obese and depressed (Dep/O, n=16), currently obese and never depressed (ND/O, n=13), and healthy weight and never depressed (ND/HW, n=16) females when participants viewed oddball valenced target face pictures, and whether TSF scores can be used to determine correlation to depression risk. Results showed that the ND/O group processes weight status and valence of facial stimuli more similarly to the Dep/O group than as compared to the ND/ HW participants. In contrast, with the measure of an eating-related cognitive distortion, Thought-Shape Fusion, ND/O individuals were more similar to ND/HW. Results support obesity being a risk factor for depression and support the P3 component being an objective, unbiased marker for depression risk in obese individuals. TSF scores were found to have good sensitivity and excellent specificity for classifying depression in obese individuals, indicating this self-report measure may be useful in determining depression risk in currently obese individuals. This research may highlight some useful tools for clinicians that indicate presence of cognitive risk factors for development of depression in obese individuals.