Abstract
The present study focuses on the role of amygdala reactivity to negative facial expressions in major depressive disorder (MDD). A number of studies have found amygdala hyperreactivity in depressed patients compared with control subjects. This has been interpreted in terms of a negative depressive bias in attention and memory, given the amygdala's role in attending to and remembering negatively valenced stimuli. However, failure to find amygdala hyperreactivity in depression is not uncommon, and a recent failure to replicate the effect with an extremely well-powered analysis of UK Biobank data led many to conclude that there is no role for amygdala reactivity in depression. In the present study, the same UK Biobank sample is used to evaluate an alternative hypothesis about the relation between MDD and amygdala reactivity, namely that people who are vulnerable to MDD will show elevated amygdala reactivity. Depression history was used as a proxy for vulnerability. Given the discrepancies among different measures of depression history, three distinct measures of depression history were used, and regression analyses assessed the strength of the relation between the history measures and amygdala reactivity. Two of three assessments of depression history showed highly significant relations with amygdala reactivity, the third showing a combination of significant, borderline and nonsignificant trends depending on the analysis.