Meta-analysis finds error processing generally comparable in MDD versus healthy controls

This systematic review and meta-analysis examined error processing in major depressive disorder (MDD) by comparing amplitudes of error-related negativity (ERN) and error positivity (Pe) between MDD patients and healthy controls. The analysis included data from 22 studies for ERN and 10 studies for Pe. The population consisted of patients with MDD and healthy controls, though specific sample sizes and study settings were not reported.

The main finding was that ERN amplitude showed no significant difference between MDD patients and healthy controls. For Pe amplitude, results were generally comparable overall, but a significant reduction was observed in two specific contexts: in MDD patients with comorbid conditions (p = 0.001) and in studies that used the Flanker task paradigm (p = 0.012). Effect sizes were reported as Hedges' g, but specific values and absolute numbers were not provided. No intervention or exposure was studied; the analysis compared MDD patients to healthy controls.

Safety and tolerability data were not reported. A key limitation, as noted in the abstract, is that the findings remain inconsistent. The analysis identified moderators only for Pe, with no significant moderators found for ERN. The practice relevance was not reported. This meta-analysis synthesizes observational event-related potential studies, showing association only, not causation. The evidence suggests that while overall group differences in ERN and Pe may be minimal, specific clinical and methodological factors can influence Pe amplitude in MDD.