Attentional control, rumination and recurrence of depression.

Background: Depressive recurrence is highly prevalent and adds significantly to the burden of depressive disorder. Whilst some clinical predictors of recurrence have been clearly demonstrated (e.g. residual symptoms, previous episodes), the cognitive and psychological processes that may contribute to recurrence risk are less well established. In this study we examine whether cognitive flexibility deficits and rumination are related to recurrence in a remitted clinical sample.
Method: We compared remitted patients with 2 or more previous depressive episodes (N = 69) to a matched group of healthy controls (N = 43). Cognitive flexibility was measured using the Internal Shift Task (IST) and a version of the Exogenous Cueing Task (ECT); rumination was assessed with the Ruminative Responses Scale.
Results: IST and ECT performance did not differ between remitted patients and controls. Remitted patients had higher levels of rumination than controls. Within the remitted patient group, faster disengagement from angry and happy faces on the ECT was predictive of shorter time to recurrence (hazard ratio for 1 standard deviation, (HR _SD ) = 0.563 [CI, 0.381-0.832], p = 0.004, (HR _SD ) = 0.561 [CI, 0.389-0.808], p = 0.002, respectively). Rumination predicted recurrence (HR _SD  = 1.526 [CI, 1.152-2.202]; p = 0.003) but was not related to emotional disengagement.
Limitations: We had low power to detect small effects for the analysis within remitted patients.
Conclusions: Whilst cognitive flexibility in remitted patients was not impaired relative to controls, rapid disengagement from emotional stimuli and rumination were independently associated with time to recurrence. Cognitive flexibility may be an important indicator of recurrence risk, and a target for interventions to reduce recurrence.
(Copyright © 2019. Published by Elsevier B.V.)