Does objectively-assessed sleep moderate the association between history of major depressive disorder and task-switching?

Impaired cognitive flexibility in major depressive disorder: Evidences from spatial-temporal ERPs analysis

BACKGROUND

Major Depressive Disorder (MDD) may exhibit impairments in cognitive flexibility. This study investigated whether the cognitive flexibility deficits in MDD are evident across general stimuli or specific to emotional stimuli, while exploring the underlying neuropsychological mechanism.

METHODS

A total of 41 MDD patients and 42 healthy controls (HCs) were recruited. Event-related potentials (ERPs) were recorded when participants performed a non-emotional and an emotional task switching paradigm (N-ETSP and ETSP), both of which assessed cognitive flexibility. Microstate and source localization analysis were applied to reflect brain activity among different brain areas during task switching.

RESULTS

In the N-ETSP, MDD group showed larger P3 difference wave (Pd3) amplitudes and longer P2 difference wave (Pd2) latencies. In the ETSP, MDD group displayed smaller N2 difference wave (Nd2) amplitudes and larger Pd3 amplitudes. The comparison of sLORETA images of emotional switch task and emotional repeat task showed that MDD group had increased activation in the precentral gyrus in microstate2 of the P2 time window and had reduced activation in the middle occipital gyrus in microstate3 of the N2 time window.

LIMITATIONS

The cross-sectional design failed to capture dynamic changes in cognitive flexibility in MDD.

CONCLUSIONS

MDD demonstrated impaired cognitive flexibility respond to both non-emotional and emotional stimuli, with greater impairment for negative emotional stimuli. These deficits are evident in abnormal ERPs component during the early attention stage and the later task preparation stage. Furthermore, abnormal emotional switching cost in MDD appears to be related to early abnormal perceptual control in the parietal-occipital cortex.

Polysomnographic parameters associated with cognitive function in patients with major depression and insomnia

OBJECTIVE

To examine whether objective sleep parameters are associated with cognitive function (CF) in patients with major depressive disorder (MDD) with chronic insomnia (CI) and whether the severity of these disorders is related to CF.

METHOD

Thirty patients with MDD with CI attending a tertiary care institution underwent two consecutive nights of polysomnographic (PSG) recording and a battery of neuropsychological tests, which included episodic memory, sustained attention, working memory, and executive function. The severity of MDD and CI was assessed by clinical scales. We examined the relationship between PSG parameters and CF, as well as whether the severity of the disorders is related to CF.

RESULTS

Linear regression analysis revealed that total sleep time (TST) was positively associated with higher learning and recall of episodic memory, as well as better attention. Slow-wave sleep (SWS) showed a positive association with better working memory. Furthermore, wake after sleep onset (WASO) was negatively associated with episodic memory and lower attention. No significant relationships were found between the severity of MDD or CI with CF.

CONCLUSION

Both sleep duration and depth are positively associated with several aspects of CF in patients with MDD with CI. Conversely, a lack of sleep maintenance is negatively related to CF in these patients. These findings could help identify modifiable therapeutic targets to reduce CF impairment.

Relationship between cognitive function and brain activation in major depressive disorder patients with and without insomnia: A functional near-infrared spectroscopy (fNIRS) study

BACKGROUND

Patients with major depressive disorder (MDD) frequently present with sleep disturbances and cognitive impairment. The purpose of this study was to investigate whether cognitive impairment is more severe in MDD patients with insomnia, and the underlying neural mechanisms.

METHODS

A total of 41 MDD patients with insomnia and 43 MDD patients without insomnia were recruited. We used functional near-infrared spectroscopy (fNIRS) to assess changes in oxyhemoglobin (Oxy-Hb) concentrations in the brain of patients while performing a verbal fluency task (VFT). Sleep quality was assessed by the Pittsburgh Sleep Quality Index (PSQI), cognitive function by the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), and severity of depression by the Hamilton Depression Scale (HAMD).

RESULTS

Compared to MDD patients without insomnia, those with insomnia had lower scores on the RBANS total and immediate memory, visuospatial/constructional, and delayed memory subscales, as well as lower oxy-Hb concentrations in the bilateral dorsolateral prefrontal cortex (DLPFC) and bilateral medial prefrontal cortex (mPFC).Further correlation analysis showed that there was a significant correlation between the RBANS total score in all brain regions except left mPFC in MDD patients with insomnia(all p < 0.05). Further multiple linear regression showed that Oxy-Hb concentrations of left DLPFC were independently associated with RBANS total score.

CONCLUSION

Our study suggests that MDD patients with insomnia have more cognitive impairment, which is associated with impaired frontal brain activity. Our findings may provide new insights to understand the underlying neural mechanisms of both disorders MDD patients and provide potential clinical value for developing treatment strategies for insomnia in MDD patients.

Functional Near-Infrared Spectroscopy Evidence of Prefrontal Regulation of Cognitive Flexibility in Adults With ADHD

BACKGROUND

Executive function (EF) deficit is considered to be a core cognitive deficit in ADHD. The current study combined functional near-infrared spectroscopy (fNIRS) and numerical switching tasks to investigate the cognitive flexibility of adult ADHD as an important part of EF.

MATERIAL AND METHODS

The Wender Utah Rating Scale and the adult ADHD self-rating scale were respectively used to assess ADHD symptoms in childhood and adulthood. A 22 adults with ADHD and 24 healthy controls (HCs) participated in the large/small and odd/even switching tasks.

RESULTS

Behavioral results were indicative of the ADHD switch costs being lower than the HCs. The fNIRS results also showed that ADHD's frontal eye field was over-activated both in magnitude and switched judgment tasks. The dorsolateral prefrontal cortex was also over-activated in magnitude judgment tasks.

CONCLUSION

These results revealed that adults with ADHD's cognitive flexibility performed better than the HCs, which result is different from mainstream ideas that EF is a core deficit in ADHD.

A Cognitive Biotype of Depression and Symptoms, Behavior Measures, Neural Circuits, and Differential Treatment Outcomes: A Prespecified Secondary Analysis of a Randomized Clinical Trial

Importance

Cognitive deficits in depression have been associated with poor functional capacity, frontal neural circuit dysfunction, and worse response to conventional antidepressants. However, it is not known whether these impairments combine together to identify a specific cognitive subgroup (or "biotype") of individuals with major depressive disorder (MDD), and the extent to which these impairments mediate antidepressant outcomes.

Objective

To undertake a systematic test of the validity of a proposed cognitive biotype of MDD across neural circuit, symptom, social occupational function, and treatment outcome modalities.

Design, Setting, and Participants

This secondary analysis of a randomized clinical trial implemented data-driven clustering in findings from the International Study to Predict Optimized Treatment in Depression, a pragmatic biomarker trial in which patients with MDD were randomized in a 1:1:1 ratio to antidepressant treatment with escitalopram, sertraline, or venlafaxine extended-release and assessed at baseline and 8 weeks on multimodal outcomes between December 1, 2008, and September 30, 2013. Eligible patients were medication-free outpatients with nonpsychotic MDD in at least the moderate range, and were recruited from 17 clinical and academic practices; a subset of these patients underwent functional magnetic resonance imaging. This prespecified secondary analysis was performed between June 10, 2022, and April 21, 2023.

Main Outcomes and Measures

Pretreatment and posttreatment behavioral measures of cognitive performance across 9 domains, depression symptoms assessed using 2 standard depression scales, and psychosocial function assessed using the Social and Occupational Functioning Assessment Scale and World Health Organization Quality of Life scale were analyzed. Neural circuit function engaged during a cognitive control task was measured using functional magnetic resonance imaging.

Results

A total of 1008 patients (571 [56.6%] female; mean [SD] age, 37.8 [12.6] years) participated in the overall trial and 96 patients participated in the imaging substudy (45 [46.7%] female; mean [SD] age, 34.5 [13.5] years). Cluster analysis identified what may be referred to as a cognitive biotype of 27% of depressed patients with prominent behavioral impairment in executive function and response inhibition domains of cognitive control. This biotype was characterized by a specific profile of pretreatment depressive symptoms, worse psychosocial functioning (d = -0.25; 95% CI, -0.39 to -0.11; P < .001), and reduced activation of the cognitive control circuit (right dorsolateral prefrontal cortex: d = -0.78; 95% CI, -1.28 to -0.27; P = .003). Remission was comparatively lower in the cognitive biotype positive subgroup (73 of 188 [38.8%] vs 250 of 524 [47.7%]; P = .04) and cognitive impairments persisted regardless of symptom change (executive function: ηp2 = 0.241; P < .001; response inhibition: ηp2 = 0.750; P < .001). The extent of symptom and functional change was specifically mediated by change in cognition but not the reverse.

Conclusions and Relevance

Our findings suggest the presence of a cognitive biotype of depression with distinct neural correlates, and a functional clinical profile that responds poorly to standard antidepressants and instead may benefit from therapies specifically targeting cognitive dysfunction.

Trial Registration

ClinicalTrials.gov Identifier: NCT00693849.

The relationship between sleep disturbance and cognitive impairment in mood disorders: A systematic review

BACKGROUND

Cognitive impairment experienced by people with bipolar disorders (BD) or major depressive disorder (MDD) is associated with impaired psychosocial function and poorer quality of life. Sleep disturbance is another core symptom of mood disorders which may be associated with, and perhaps worsen, cognitive impairments. The aim of this systematic review was to critically assess the relationship between sleep disturbance and cognitive impairment in mood disorders.

METHODS

In this systematic review, relevant studies were identified using electronic database searches of PsychINFO, MEDLINE, Embase and Web of Science.

FINDINGS

Fourteen studies were included; eight investigated people with BD, five investigated people with MDD, and one included both people with MDD and people with BD. One study was an intervention for sleep disturbance and the remaining thirteen studies used either a longitudinal or cross-sectional observational design. Ten studies reported a significant association between subjectively measured sleep disturbance and cognitive impairment in people with MDD or BD after adjusting for demographic and clinical covariates, whereas no such association was found in healthy participants. Two studies reported a significant association between objectively measured (actigraphy or polysomnography) sleep abnormalities and cognitive impairment in mood disorders. One study of cognitive behavioural therapy for insomnia modified for BD (CBTI-BD) found an association between improvements in sleep and cognitive performance in BD.

INTERPRETATION

There is preliminary evidence to suggest a significant association between sleep disturbance and cognitive impairment in mood disorders. These findings highlight the need for further research of sleep disturbances and cognitive impairment in people with mood disorders.