Attentional bias in depression: understanding mechanisms to improve training and treatment

Abstract

One of the most common symptoms of depression is the tendency to attend to negative stimuli in the world and negative thoughts in mind. This symptom is especially nefarious because it is also a cause - biasing processing to negatively valenced information, thus worsening mood, and exacerbating the condition. Here we attempt to systematize the diverse body of recent research on the negative attentional bias from across cognitive and clinical psychology in order to identify recurring themes and devise potential mechanistic explanations. We leverage theoretical progress in our understanding of healthy attention systems in terms of internal versus external components. With this lens, we review approaches to training attention that might reduce the negative attentional bias, including behavioral interventions and real-time neurofeedback. Although extant findings are somewhat mixed, these approaches provide hope and clues for the next generation of treatments.

Copyright © 2019 Elsevier Ltd. All rights reserved.

Figures

Figure 1.

Neural circuit proposed in [52] for how both stimulus-driven and goal-directed pathways can drive the negative attentional bias in depressed subjects (dashed lines indicate weakened functional connections in depression). Negative stimuli trigger a cascade of increased activity from thalamus → amygdala → subgenual cingulate. The DLPFC and thus ACC show reduced activity, which in turn reduces inhibition of the amygdala and prolongs processing of negative stimuli.

Figure 2.

Eye-tracking data from [25] showing reaction times after either attending toward or away from an emotional face (paired with a neutral face), in both depressed (MDD) and control (CTL) participants. The results clearly show that the main impairment in depressed patients involves disengaging from sad faces.

Figure 3.

Neurofeedback training from [44]. (A) Two neurofeedback target ROIs: left amygdala for the experimental group and left horizontal segment of the intraparietal sulcus for the control group. (B) Example feedback display when subjects think of happy memories and try to increase the red bar (signaling ROI activity) to the target blue bar height. (C) Results adapted from [43] showing a change in amygdala activity over training for the experimental group (green) and not the control group (orange), matching a behavioral improvement (lower depression severity scores) specific to the experimental group.