Attentional control, rumination and recurrence of depression

Highlights

• Cognitive flexibility in remitted patients was not impaired relative to controls.

• Self-report rumination predicted faster recurrence in remitted patients.

• Rapid disengagement from angry and happy faces predicted faster recurrence.

• The relation between disengagement and recurrence was not mediated by rumination.

• Rapid attentional disengagement from emotional stimuli may be a prevention target.

Abstract

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.

Introduction

Of all psychiatric disorders, Major Depressive Disorder (MDD) is ranked as the single largest contributor to global disability (World Health Organisation, 2017). An important factor that adds to the large burden of MDD is the high risk of recurrence after remission from a depressive episode. MDD recurrence rates are typically reported to be above 50% (Eaton et al., 2008, Hardeveld et al., 2013, Steinert et al., 2014), with rates as high as 90% within 10–15 years in clinical samples with 3 or more previous episodes (Beshai et al., 2011, Bockting et al., 2015). Clinical characteristics such as the number of previous episodes and residual symptoms have been identified as among the strongest predictors of recurrence (Hardeveld et al., 2010, Kessing et al., 2004). Whether cognitive and psychological processes associated with MDD (e.g. habitual maladaptive thinking patterns, deficits or biases in cognition) predict recurrence of MDD is less well established.

One important cognitive risk factor for MDD is rumination: a type of repetitive negative thinking (RNT), that has been defined as ‘repetitively and passively focusing on the symptoms of distress and the possible causes and consequences of these symptoms' (Nolen-Hoeksema et al., 2008). High levels of rumination have been consistently shown to predict the onset, severity and maintenance of depressive episodes (Nolen-Hoeksema et al., 2008, Watkins, 2008). Further, residual rumination during remission from earlier episodes is considered a risk factor for recurrence of depression (Watkins, 2009). A small number of studies have specifically examined a possible role for rumination in predicting depressive recurrence. Michalak et al. (2011) found that higher levels of rumination predicted shorter time to recurrence within 12 months after a mindfulness based treatment (Michalak et al., 2011). Scores on a cognitive reactivity measure (Leiden Index of Depression Sensitivity; LEIDS (Van der Does, 2002, Van der Does, 2005)) including the rumination subscale were also associated with time to recurrence of depression (Figueroa et al., 2015). In contrast, Timm et al. (2017) did not show a relationship between trait rumination and time to recurrence, but found that rumination predicted levels of residual symptoms at 6 and 30 months after treatment (Timm et al., 2017).

A key vulnerability that might underlie both depression and rumination is deficits in cognitive control or flexibility: cognitive flexibility concerns a set of processes including controlling and shifting attention, inhibiting irrelevant information, and updating working memory (Miyake et al., 2000). Attentional control, i.e. the ability to direct attention flexibly according to current goals, is considered to be one of the core abilities supporting and serving cognitive flexibility (Mackie et al., 2013). Experimental evidence from a range of tasks indicates that these impairments not only occur in clinically depressed groups but also in vulnerable populations, including individuals with subclinical symptoms and remitted groups (Koster et al., 2017b, Snyder, 2013).

Empirical studies now indicate that rumination is also closely associated with deficits in cognitive flexibility, particularly impairments in attentional inhibition and shifting (De Lissnyder et al., 2011, Mor and Daches, 2015, Vanderhasselt et al., 2011, Whitmer and Banich, 2007). Several theoretical models have proposed that cognitive deficits increase vulnerability to rumination, by reducing the ability to exert control over these thought processes and impairing the use of other emotional regulation strategies, such as reappraisal or distraction (Hirsch and Mathews, 2012, Koster et al., 2011, Mor and Daches, 2015, Watkins and Nolen-Hoeksema, 2014). For instance, Demeyer et al. (2012) showed that deficits on an attentional control task were associated with depressive symptoms one year later and this relationship was mediated by rumination. Similarly, Hsu et al. (2015) showed that rumination mediated the relationship between self-reported attentional control and symptoms of depression/anxiety. However, possible relationships between deficits in cognitive flexibility, rumination and depressive recurrence have been less well examined. Most existing studies are limited by reliance on self-report measures of cognitive flexibility and use of cross-sectional designs.

In the current study we therefore consider the potential role of rumination and deficits in CC in predicting depressive recurrence, in a group of patients remitted from at least 2 previous episodes of MDD. To examine cognitive flexibility we use two different tasks: (1) IST (Internal Shift Task), which allows the examination of whether recurrence is related to impairments in the capacity to shift between emotional or non-emotional information held in working memory (De Lissnyder et al., 2012b) and (2) ECT (Exogenous Cueing Task), which presents a fine-grained measure of attentional bias, differentiating between engagement and disengagement for emotional stimuli and short and longer durations of presentation (Koster et al., 2005). Examining the role of cognitive flexibility deficits and rumination in depression is theoretically important in understanding vulnerability to onset and recurrence of this disorder. These models also have potential clinical utility; both cognitive flexibility deficits and rumination are possible targets for treatment and preventative interventions (Koster et al., 2017b, Martell et al., 2013, Mor and Daches, 2015, Siegle et al., 2014, Topper et al., 2017, Topper et al., 2010, Watkins et al., 2007).

The aim of the current study was to examine performance on two cognitive flexibility tasks in a remitted patient group: firstly, a version of the exogenous cueing task (ECT), and secondly the Internal Shift Task (IST). Further, we aimed to consider how cognitive flexibility performance related to both rumination and time to depressive recurrence. Previous studies using the ECT have shown that clinically depressed participants show stronger attentional engagement with, and slower disengagement from, angry faces compared to healthy controls, respectively (Leyman et al., 2007).

Previous work using the IST has demonstrated that patients with MDD show general shifting impairments across emotional and neutral conditions, and rumination is associated with the degree of impairment (De Lissnyder et al., 2012c). For both tasks, there is a lack of previous research in remitted depressed groups.

We hypothesised that (1) Cognitive flexibility is poorer in the remitted patient group compared to controls; (2) Within the remitted patient group, rumination is associated with difficulties in disengaging and shifting attention, particularly when processing negatively valenced emotional stimuli; (3) High rumination and cognitive flexibility deficits (difficulties in disengaging and shifting attention) are associated with shorter time to recurrence of depression, and (4) Rumination mediates the relationship between cognitive flexibility deficits and recurrence.