Domain-specific impairment in cognitive control among remitted youth with a history of major depression.

Aim: Impairment in neuropsychological functioning is common in major depressive disorder (MDD), but it is not clear to what degree these deficits are related to risk (e.g. trait), scar, burden or state effects of MDD. The objective of this study was to use neuropsychological measures, with factor scores in verbal fluency, processing speed, attention, set-shifting and cognitive control in a unique population of young, remitted, unmedicated, early course individuals with a history of MDD in hopes of identifying putative trait markers of MDD.
Methods: Youth aged 18-23 in remission from MDD (rMDD; n = 62) and healthy controls (HC; n = 43) were assessed with neuropsychological tests at two time points. These were from four domains of executive functioning, consistent with previous literature as impaired in MDD: verbal fluency and processing speed, conceptual reasoning and set-shifting, processing speed with interference resolution, and cognitive control.
Results: rMDD youth performed comparably to HCs on verbal fluency and processing speed, processing speed with interference resolution, and conceptual reasoning and set-shifting, reliably over time. Individuals with rMDD demonstrated relative decrements in cognitive control at Time 1, with greater stability than HC participants.
Conclusion: MDD may be characterized by regulatory difficulties that do not pertain specifically to active mood state or fluctuations in symptoms. Deficient cognitive control may represent a trait vulnerability or early course scar of MDD that may prove a viable target for secondary prevention or early remediation.
(© 2015 Wiley Publishing Asia Pty Ltd.)