Cognitive Processing of Person-Referent Words in Depression and Obesity

Abstract

The purpose of this study was to investigate differences in the cognitive processing of person-referent words in depression and obesity and identify a cognitive marker of depression vulnerability in obesity. Three groups of participants (obese, non-depressed (OND) (BMI30); obese, clinically depressed (OD) (BMI30); healthy weight (HW) (BMI 18.5-24.9), non-depressed) viewed positive, negative, and neutral words while event-related potential (ERP) data was collected. The valenced words were person-referent and described either physical characteristics or non-physical characteristics such as personality and intellect. A repeated measures ANOVA was used to analyze attention allocation to salient stimuli as index by P3 difference wave amplitudes. The ANOVA compared attention to word valence and physicality in these three groups. The results indicated three main findings: 1) The P3 oddball paradigm with valenced (rare) and neutral (frequent) words produces a reliable P3 ERP component. 2) The magnitude of the P3 is influenced by word valence, with an attention bias towards negative words across groups. 3) Valence impacts the response to the physicality of the words such that there is a greater attentional bias towards negative physical words than positive physical words and a greater attentional bias towards negative physical words than to negative non-physical words across groups. There was also a trend for the OND group to mirror the HW group for positive words and mirror the OD group for negative words, with heightened attention to negative, physical words. This trend towards heightened attention to negative information in the OD group compared to the HW group and the extent to which obese individuals generalize negative self-referent information suggest potential risks for depression vulnerability in obesity. This knowledge may help guide cognitive therapy for obese individuals who are at risk for depression, emphasizing the importance of reinforcing positive self-attributes and avoiding negative self-focus and ruminative attention.