Remediation of depression-related cognitive impairment: cognitive control training as treatment augmentation

Treatment Response Following Adaptive PASAT Training for Depression Vulnerability: a Systematic Review and Meta-Analysis

In recent years, cognitive control training (CCT) has gained momentum as an intervention to remediate cognitive impairments and decrease depressive symptoms. One promising operationalization to train cognitive control is the adaptive Paced Auditory Serial Addition Task (aPASAT). In this systematic review and meta-analysis of aPASAT training, the efficacy of the intervention and potential moderators were examined. The PsycINFO, MEDLINE, Embase, Web of Science and Cochrane Library electronic databases were searched for studies examining aPASAT training for depressive symptomatology or rumination. Nineteen studies (n = 1255) were included, comprising of depressed patients, remitted depressed patients, at-risk, and healthy participants. We found small significant effects directly after training for both depressive symptomatology and rumination, with similar effect sizes at follow-up. Subgroup analyses suggest a significantly higher mean effect of aPASAT training in non-healthy populations for rumination immediately following training, but not for depressive symptomatology. The amount of training sessions did not moderate effects of CCT. aPASAT has a small but significant effect on depressive symptoms, with direct effects immediately after training, as well as sustained long-term effects. It is currently unclear how many sessions are required for sustained effects due to heterogeneity in training dosage and absence of sufficient trials. Our results suggest that aPASAT training may be most effective for at-risk, remitted- and clinically depressed populations. The effect sizes resulting from this meta-analysis could be used to adequately power future research, which could investigate a dose-response relationship and examine potential treatment gains when combining CCT with other antidepressant interventions.

Deficits in specific executive functions manifest by severity in major depressive disorder: a comparison of antidepressant naïve inpatient, outpatient, subclinical, and healthy control groups

Introduction

Previous research has highlighted the executive function (EF) deficits present in depressed patients; however, conflicting results exist regarding the impact of depression severity on the size of these deficits. This study aimed to compare deficits in EF between antidepressant naïve inpatient and outpatient depressed, a group with subclinical depression symptoms, and a healthy control group while controlling for education, sex, and age.

Methods

In cross-sectional research, 245 antidepressant naive participants (46 inpatient, 68 outpatient, 65 subclinical, and 67 healthy control individuals) were recruited by convenience sampling. The Structured Clinical Interview for DSM-5 Disorders (SCID-5) and Beck Depression Inventory-II (BDI-II) were used to assess depression. EF was measured using several neuropsychological tests, including the Stroop Color-Word Test, the Wisconsin Card Sorting Test, and the N-back Test, which assessed the components of Inhibition, Shifting, and Updating, respectively. Multivariate analysis of covariance revealed a significant difference between the groups in EF components (p < 0.001). Pairwise comparisons further showed that inpatient and outpatient patients had more depressive symptoms and worse EF performance than subclinical and healthy control groups (p < 0.05).

Results

In the analysis of EF measures, a significant difference was found among the four groups, with post-hoc tests revealing variations in specific EF components. Overall, patients with more severe depressive symptoms show more deficits in EF. Additionally, correlations between clinical characteristics and EF measures varied across patient groups, but many correlations became non-significant after adjusting for the false discovery rate (FDR).

Discussion

This study emphasizes the impact of depression severity on deficits in the EF of depressed patients and at-risk populations. Consequently, it is important to consider executive dysfunctions as an underlying vulnerability in the development and persistence of depressive disorder.

Boosting affective control with bifrontal transcranial direct current stimulation (tDCS): a proof-of-concept study in healthy individuals

Affective control refers to the ability to regulate emotions and is considered a marker of mental health. Transcranial direct current stimulation (tDCS), a non-invasive brain stimulation technique, holds promise to enhance affective control. In this between-subjects study in healthy individuals, we investigated the effects of bifrontal tDCS on core processes and higher-level markers of affective control. As such, we assessed direct tDCS effects on emotional interference during an affective control task and indirect effects on an instructed reappraisal task afterward. Results showed that the affective control task combined with active tDCS, compared to sham, resulted in enhanced cognitive emotion regulation. Specifically, participants in the active tDCS condition showed an increased propensity to use reappraisal and were more successful in doing so. Moreover, there was reduced vagally mediated heart rate variability indicative of attenuated emotion and self-regulation, in the sham, but not in the active condition. Surprisingly, there were no effects of tDCS on emotional interference during the affective control task, with Bayesian analyses showing extreme evidence against these effects. Nevertheless, there was a positive association between the emotional interference during the affective control task and participants' reappraisal success afterward for the active, but not the sham tDCS condition. The study offers valuable insights to guide future work on combined tDCS with affective control tasks or training on the ability to regulate emotions.

Cognitive remediation for depression vulnerability: Current challenges and new directions

It is increasingly acknowledged that cognitive impairment can play an important role in depression vulnerability. Therefore, cognitive remediation strategies, and cognitive control training (CCT) procedures have gained attention in recent years as possible interventions for depression. Recent studies suggest a small to medium effect on indicators of depression vulnerability. Despite initial evidence for the efficacy and effectiveness of CCT, several central questions remain. In this paper we consider the key challenges for the clinical implementation of CCT, including exploration of (1) potential working mechanisms and related to this, moderators of training effects, (2) necessary conditions under which CCT could be optimally administered, such as dose requirements and training schedules, and (3) how CCT could interact with or augment existing treatments of depression. Revisiting the CCT literature, we also reflect upon the possibilities to evolve toward a stratified medicine approach, in which individual differences could be taken into account and used to optimize prevention of depression.

Individual differences associated with treatment adherence and transfer effects following gamified web-based cognitive control training for repetitive negative thinking

Recent research suggests beneficial effects of cognitive control training (CCT) on repetitive negative thinking (RNT), a key risk factor for internalizing symptomatology. However, relatively little is known regarding predictors of adherence to internet-delivered CCT as well as moderators of treatment effects for this intervention. Answering these questions could improve efficiency of clinical implementation of CCT as an eHealth intervention. The current pre-registered single-arm trial set-out to address these questions using a web-based gamified CCT procedure based on the adaptive Paced Auditory Serial Addition Task. Participants (N = 382) entered the internet-based study, where we observed considerable drop-out during the assessment phase and the first training sessions. Emotional stability and resilience emerged as predictors for deciding not to commence the intervention. Drop-out throughout the course of CCT was explained by age, emotion regulation-, and personality factors. We used latent profile analysis, a probabilistic modeling approach, to identify clusters of participants (User Profiles) based on indicators of baseline cognitive- and emotional functioning, training progress, and user experience. We obtained three User Profiles, reflecting low-, moderate-, and high-risk status. Effortful control, emotion regulation, internalizing symptomatology, resilience, and emotional stability played a central role in these User Profiles. Interestingly, User Profile predicted training related cognitive gains, as well as effects of CCT on anxiety- and stress symptoms, and reappraisal. Our findings suggest that CCT is most effective for the moderate- and high-risk groups. In addition, the high-risk group would likely benefit from a more intensive training procedure or repeated administration of the training procedure over time to foster long-term retention of training related gains.

Investigating mechanisms of cognitive control training: neural signatures of PASAT performance in depressed patients

Major depression disorder (MDD) is characterized by cognitive control (CC) dysfunctions associated with increased attention toward negative information. The paced auditory serial addition task (PASAT) has been used as a targeted training of CC and studies show promising effects on depressive symptoms. However, neural mechanisms underlying its efficacy are still unclear. Based on previous findings of feedback-locked event-related potentials in healthy subjects, we investigated neural signatures during PASAT performance in 46 depressed patients. We found significantly larger amplitudes after negative than positive feedback for the P300 and late positive potential (LPP). However, this difference was not significant for the feedback-related negativity (FRN). Moreover, no associations of valence-specific ERPs and PASAT performance nor depressive symptoms were found. This indicates that depressed patients seem unable to use neural activation in late feedback processing stages (P300, LPP) to adapt accordingly. Moreover, lack of valence-specific neural reaction in early feedback processing stages (FRN) might point toward emotional indifference in depressed patients.Trial registration number: NCT03518749 Date of registration: May 8, 2018.

Improved emotion regulation in depression following cognitive remediation: A randomized controlled trial

OBJECTIVE

Executive functions (EFs) play a key role in emotion regulation and, related to this, depression. Cognitive remediation (CR) targeting EFs, such as Goal Management Training (GMT) and computerized cognitive training (CCT), may reduce maladaptive emotion regulation. However, the clinical potential of GMT in the context of depression and emotion regulation remains to be tested. Hence, the primary aim of the present study was to compare effects of GMT with CCT on symptoms of emotion dysregulation.

METHOD

The paper reports the effects of a preregistered randomized controlled trial. Sixty-three participants (18-60yrs) with active or remitted depression and EF complaints were randomized to nine sessions of GMT (n = 35) or CCT (n = 28). All were assessed at baseline, post-intervention, and at 6-month follow-up. The Ruminative Response Scale and the Difficulties in Emotion Regulation Scale were employed to assess emotion regulation.

RESULTS

Both groups improved following the intervention on emotion regulation domains after controlling for intention-to-treat, including brooding rumination and on items reflecting non-accepting reactions to distress. Relative to CCT, the GMT-group demonstrated increased clarity of emotional responses in the per protocol analysis.

CONCLUSIONS

Our findings demonstrate the potential of GMT and CCT in reducing maladaptive emotion regulation in depression.

Testing the impaired disengagement hypothesis: The role of attentional control and positive metacognitive beliefs in depression

The impaired disengagement hypothesis holds that people ruminate - and thus increase their risk for depression - due to impaired attentional control and conflict signaling. We tested this hypothesis by examining the role of attentional control and conflict signaling (operationalized as positive metacognitive beliefs) in rumination and depressive symptoms. We expected that attentional control and positive metacognitive beliefs would be associated with depressive symptoms and that these associations would be cross-sectionally mediated by rumination. We tested two community samples (Study 1, N = 289; Study 2, N = 292), assessing attentional control, positive metacognitive beliefs, rumination, and depressive symptoms. In both studies, attentional control and positive metacognitive beliefs were significantly associated with rumination and depression, and path analyses corroborated the proposed mediation model. Our findings support the impaired disengagement hypothesis, and suggest that attentional control and positive metacognitive beliefs may be informative in the personalization of depression assessment and treatment.

Personalized cognitive training: Protocol for individual-level meta-analysis implementing machine learning methods

Accumulating evidence suggests that cognitive training may enhance well-being. Yet, mixed findings imply that individual differences and training characteristics may interact to moderate training efficacy. To investigate this possibility, the current paper describes a protocol for a data-driven individual-level meta-analysis study aimed at developing personalized cognitive training. To facilitate comprehensive analysis, this protocol proposes criteria for data search, selection and pre-processing along with the rationale for each decision. Twenty-two cognitive training datasets comprising 1544 participants were collected. The datasets incorporated diverse training methods, all aimed at improving well-being. These training regimes differed in training characteristics such as targeted domain (e.g., working memory, attentional bias, interpretation bias, inhibitory control) and training duration, while participants differed in diagnostic status, age and sex. The planned analyses incorporate machine learning algorithms designed to identify which individuals will be most responsive to cognitive training in general and to discern which methods may be a better fit for certain individuals.

Executive Functioning and Depressive Symptoms After Cancer: The Mediating Role of Coping

OBJECTIVE

Cognitive difficulties are a common complaint among patients with breast cancer and may adversely affect psychological well-being. In particular, problems with executive functioning (EF) may interfere with coping, which is known to influence depressive symptoms. The current study was designed to examine correlations between EF, coping, and depressive symptoms in breast cancer survivors and to longitudinally test the hypothesis that coping mediates the relationship between EF and depressive symptoms.

METHODS

Participants included 171 women with early-stage breast cancer assessed at the end of primary treatment with surgery, radiation, and/or chemotherapy and at 6 months, 1 year, and 2 years after treatment follow-ups as part of the Mind-Body Study. Participants completed questionnaires to assess subjective EF, approach and avoidant coping, and depressive symptoms, and neuropsychological testing was conducted to assess objective EF. Bivariate correlations were used to examine associations between EF, coping, and depressive symptoms. Mediation analyses were conducted using a bootstrapping approach (PROCESS).

RESULTS

At 1 year after treatment, objective and subjective EFs were correlated with avoidant coping (r = -0.172 [p = .024] and r = 0.297 [p < .001], respectively). In longitudinal analyses, use of the avoidant strategy behavioral disengagement at 1 year mediated the association between objective (95% bootstrap confidence interval = -0.282 to -0.042) and subjective (95% bootstrap confidence interval = 0.020 to 0.254) EFs at 6 months and depressive symptoms at 2 years.

CONCLUSIONS

This study highlights how problems with EF during survivorship are associated with avoidant coping and depressive symptoms. Thus, these findings identify potential cognitive and affective targets for depression intervention in this population.

Neural Signatures of Performance Feedback in the Paced Auditory Serial Addition Task (PASAT): An ERP Study

Research on cognitive control has sparked increasing interest in recent years, as it is an important prerequisite for goal oriented human behavior. The paced auditory serial addition task (PASAT) has been used to test and train cognitive control functions. This adaptive, challenging task includes continuous performance feedback. Therefore, additional cognitive control capacities are required to process this information along with the already high task-load. The underlying neural mechanisms, however, are still unclear. To explore the neural signatures of the PASAT and particularly the processing of distractive feedback information, feedback locked event-related potentials were derived from 24 healthy participants during an adaptive 2-back version of the PASAT. Larger neural activation after negative feedback was found for feedback related negativity (FRN), P300, and late positive potential (LPP). In early stages of feedback processing (i.e., FRN), a larger difference between positive and negative feedback responses was associated with poorer overall performance. This association was inverted in later stages (i.e., P300 and LPP). Together, our findings indicate stage-dependent associations between neural activation after negative information and cognitive functioning. Conceivably, increased early responses to negative feedback signify distraction, whereas higher activity at later stages reflects cognitive control processes to preserve ongoing performance.

The influence of an induced negative emotional state on autobiographical memory coherence

Individuals who experience difficulty constructing coherent narratives about significant personal experiences generally report less psychological well-being and more depressive symptoms. It remains, however, unclear whether a negative emotional state, one of the core symptoms of depression, causes this impairment in autobiographical memory coherence. The current study aimed to examine the causal relation between mood and memory coherence by means of a mood induction paradigm. A group of 165 students were randomly allocated to one of three mood groups: negative, positive, and neutral. We hypothesized that memory coherence would decrease following a negative mood induction. In addition, working memory capacity was expected to mediate the association between mood and memory coherence. Contrary to predictions, memory coherence increased following a negative mood induction. This increase was likewise observed in the positive mood group, though memory coherence remained consistent in the neutral mood group. This effect of mood on memory coherence was solely observed in female participants and not in the small male subsample. Results provided no support for the hypothesis that working memory capacity functioned as an underlying mechanism. Different theoretical explanations are discussed.

A Test of the Habit-Goal Framework of Depressive Rumination and Its Relevance to Cognitive Reactivity

The aim of the present study was to test predictions derived from the habit-goal framework of depressive rumination and investigate its relevance to cognitive reactivity-another well-known vulnerability factor to depression. Formerly depressed (FD; n=20) and never depressed (ND; n=22) participants completed self-report measures of rumination, cognitive reactivity, and habitual characteristics of rumination (e.g., lack of awareness, control, intent). A standard mood-induction task was also used to measure cognitive reactivity and an outcome-devaluation task to measure general habit vs. goal-directed behavior control. Habitual characteristics of ruminative thoughts were greater in the FD group and were related to depressive brooding and cognitive reactivity, but not reflective pondering. Reliance on habit on the outcome-devaluation task was strongly correlated with number of depression episodes, although group differences were not observed in general habit vs. goal-directed control. Habitual characteristics of rumination (e.g., greater automaticity) may explain reactivity and persistence of negative thoughts in depression. Habitual behavior control may contribute to inflexible responding and vulnerability for depression episodes.