Decreased response inhibition to sad faces during explicit and implicit tasks in females with depression: Evidence from an event-related potential study

State-dependent alterations of implicit emotional dominance during binocular rivalry in subthreshold depression

Binocular rivalry, a visual perception phenomenon where two or more percepts alternate every few seconds when distinct stimuli are presented to the two eyes, has been reported as a biomarker in several psychiatric disorders. It is unclear whether abnormalities of binocular rivalry in depression could occur when emotional rivaling stimuli are used, and if so, whether an emotional binocular rivalry test could provide a trait-dependent or state-dependent biomarker. In the current study, 34 individuals with subthreshold depression and 31 non-depressed individuals performed a binocular rivalry task associated with implicit emotional processing. Participants were required to report their perceived orientations of the rival gratings in the foreground and to neglect emotional face stimuli in the background. The participants were retested after an approximately 4-month time interval. Compared to the non-depressed group, the subthreshold depression group showed significantly longer perceptual dominance durations of the grating with emotional faces as the background (i.e., implicit emotional dominance) at the initial assessment. However, the abnormality was not found at the follow-up assessment. More importantly, we found smaller changes in depressive severity at the follow-up assessment for individuals displaying longer emotional dominance at the initial assessment than for individuals with weaker emotional dominance. The current emotional binocular rivalry test may provide an objective, state-dependent biomarker for distinguishing individuals with subthreshold depression from non-depressed individuals.

Extremely negative emotion interferes with cognition: Evidence from ERPs and time-varying brain network

In recent years, the relationship between emotion and cognition was a hot topic. However, it remains unclear which specific emotions can significantly interfere with cognition and how they do so. In this study, we designed a novel Affective Stroop experiment paradigm to investigate these issues. The extremely negative (EN), moderately negative (MN), moderately positive (MP), extremely positive (EP) and neutral pictures were displayed before Stroop tasks. The behavioral results revealed that EN emotion significantly interfered with cognitive performance compared to other types of emotions, with a significant increase in reaction time under the EN emotion condition (P < 0.05). Furthermore, the dynamic brain mechanisms were analyzed from both Event-Related Potential (ERP) and time-varying brain network perspectives. Results showed that EN emotion evoked larger N2, P3, and LPP amplitudes in the frontal, parietal, and occipital brain regions. In contrast, the Stroop task under EN condition led to smaller N2, P3, and LPP amplitudes compared to neutral condition. This indicates that EN emotion was prioritized and consumed more cognitive resources relative to neutral emotion. During the P3 and LPP stages, we observed enhanced bottom-up connections between the parietal and frontal regions while the processing of EN emotion. Additionally, there were stronger top-down cognitive control connections from the frontal to the occipital regions while processing the Stroop task under EN condition. These findings consistently suggest that EN emotion interferes with cognition by consuming more cognitive resources, and the brain needs to enhance cognitive control to support Stroop task execution.

Negative inhibition is poor in sub-threshold depression individuals: Evidence from ERP and a Go/No-go task

In this study, Go/No-go task combined with ERP technology were used to explore the characteristics of negative emotion inhibition in SD and healthy individuals and whether there are differences between negative emotion inhibition and neutral emotion inhibition in SD. The results showed that SD showed the same poor negative inhibition as depressive patients in behavior, but there was no significant difference between SD and CG in ERPs. Overall, compared with neutral emotional information, negative emotional information would reduce attention control in conflict processing, lead to faster conflict processing, attract attention, occupy more cognitive resources, and be more difficult to inhibit. It is concluded that the negative attention bias of SD individuals is only reflected in the bottom-up stimulation processing, but has not developed into the top-down cognitive control, which also suggests that the corresponding intervention measures at the early stage of depression may have better effects.

Attention-deficit hyperactivity disorder traits are a more important predictor of internalising problems than autistic traits

Autism Spectrum Disorder (ASD) and Attention-Deficit Hyperactivity Disorder (ADHD) are both linked to internalising problems like anxiety and depression. ASD and ADHD also often co-occur, making their individual statistical contributions to internalising disorders difficult to investigate. To address this issue, we explored the unique associations of self-reported ASD traits and ADHD traits with internalising problems using a large general population sample of adults from the United Kingdom (N = 504, 49% male). Classical regression analyses indicated that both ASD traits and ADHD traits were uniquely associated with internalising problems. Dominance and Bayesian analyses confirmed that ADHD traits were a stronger, more important predictor of internalising problems. However, brief depression and anxiety measures may not provide a comprehensive index of internalising problems. Additionally, we focused on recruiting a sample that was representative of the UK population according to age and sex, but not ethnicity, a variable that may be linked to internalising disorders. Nevertheless, our findings indicate that while ASD and ADHD uniquely predict internalising problems, ADHD traits are a more important statistical predictor than ASD traits. We discuss potential mechanisms underlying this pattern of results and the implications for research and clinical practice concerning neurodevelopmental conditions.

Repetitive transcranial magnetic stimulation promotes response inhibition in patients with major depression during the stop-signal task

BACKGROUND

Response inhibition (RI) deficit is an aspect of cognitive impairment in depressed individuals, but currently no effective treatment has been established. This study aimed to explore the effect of individualized repetitive transcranial magnetic stimulation (rTMS) targeting the left dorsolateral prefrontal cortex (lDLPFC)-nucleus accumbens (NAcc) network on RI in patients with major depressive disorder (MDD).

METHODS

Fourty-four patients diagnosed with MDD were randomized to receive 15 once-daily sessions of active (10 Hz, 100% of resting motor threshold) or sham rTMS within a double-blind, sham-controlled trial. We measured the efficacy of rTMS by the improvements in behavioral and neurological manifestations during the stop-signal task. The Hamilton Depression Rating Scale-17 items (HAMD-17) was used to assess depressive symptoms. We analyzed the differences in RI performance between MDD patients and 30 healthy controls (HCs) at baseline and assessed whether MDD patients who completed rTMS treatment had comparable RI ability to HCs.

RESULTS

At baseline, the depressed patients showed longer stop-signal response time (SSRT), smaller P3 amplitudes, and weaker theta-band power in successful stop trials (SSTs) than HCs. The active group exhibited RI ability comparable to that of HCs after rTMS treatment, but the improvements were not significant in the sham group. The active group showed significant remission in depression symptoms post-treatment compared to the sham group, and the changes in P3 amplitudes and theta-band power during SSTs were negatively correlated with the decrease of HAMD-17 scores.

CONCLUSION

The depressed patients have impaired RI and treatment with the individualized rTMS protocol may be an effective approach.

Impairment of response inhibition to emotional face stimuli in individuals with subclinical depression

Response inhibition, a crucial component of executive function, is closely related to personal impulse control, social adaption, and mental health. Previous studies have found response inhibition deficit in patients with major depressive disorder, but whether it also exists in individuals with subclinical depression (SD) remains unclear. This study aimed to identify the ability of response inhibition to emotional face stimuli both under explicit and implicit conditions in individuals with SD. Thirty-six subclinical depressed college students and 39 healthy individuals were recruited and administered the non-emotional, explicit, and implicit emotional stop-signal tasks (SSTs). Mixed-model analyses of variance were used to analyze the differences between and within groups. In implicit emotional SST, the results showed a significant longer stop-signal response time, a shorter stop-signal delay time, a shorter go reaction time, and a similar proportion of stop success in the SD group compared to healthy controls. However, the above indices showed no significant difference between the two groups in the non-emotional SST and explicit emotional SST. These findings suggest a possible defect of response inhibition in implicit emotional processing in individuals with SD, which may potentially serve as a marker of susceptibility to depression and thus be applied to early screening and intervention for major depressive disorder.

The association between implicit and explicit affective inhibitory control, rumination and depressive symptoms

Inhibitory control underlies one's ability to maintain goal-directed behavior by inhibiting prepotent responses or ignoring irrelevant information. Recent models suggest that impaired inhibition of negative information may contribute to depressive symptoms, and that this association is mediated by rumination. However, the exact nature of this association, particularly in non-clinical samples, is unclear. The current study assessed the relationship between inhibitory control over emotional vs. non-emotional information, rumination and depressive symptoms. A non-clinical sample of 119 participants (mean age: 36.44 ± 11.74) with various levels of depressive symptoms completed three variations of a Go/No-Go task online; two of the task variations required either explicit or implicit processing of emotional expressions, and a third variation contained no emotional expressions (i.e., neutral condition). We found reductions in inhibitory control for participants reporting elevated symptoms of depression on all three task variations, relative to less depressed participants. However, for the task variation that required implicit emotion processing, depressive symptoms were associated with inhibitory deficits for sad and neutral, but not for happy expressions. An exploratory analysis showed that the relationship between inhibition and depressive symptoms occurs in part through trait rumination for all three tasks, regardless of emotional content. Collectively, these results indicate that elevated depressive symptoms are associated with both a general inhibitory control deficit, as well as affective interference from negative emotions, with implications for the assessment and treatment of mood disorders.

Aberrant Prefrontal-Thalamic-Cerebellar Circuit in Schizophrenia and Depression: Evidence From a Possible Causal Connectivity

Neuroimaging studies have suggested the presence of abnormalities in the prefrontal-thalamic-cerebellar circuit in schizophrenia (SCH) and depression (DEP). However, the common and distinct structural and causal connectivity abnormalities in this circuit between the two disorders are still unclear. In the current study, structural and resting-state functional magnetic resonance imaging (fMRI) data were acquired from 20 patients with SCH, 20 depressive patients and 20 healthy controls (HC). Voxel-based morphometry analysis was first used to assess gray matter volume (GMV). Granger causality analysis, seeded at regions with altered GMVs, was subsequently conducted. To discover the differences between the groups, ANCOVA and post hoc tests were performed. Then, the relationships between the structural changes, causal connectivity and clinical variables were investigated. Finally, a leave-one-out resampling method was implemented to test the consistency. Statistical analyses showed the GMV and causal connectivity changes in the prefrontal-thalamic-cerebellar circuit. Compared with HC, both SCH and DEP exhibited decreased GMV in middle frontal gyrus (MFG), and a lower GMV in MFG and medial prefrontal cortex (MPFC) in SCH than DEP. Compared with HC, both patient groups showed increased causal flow from the right cerebellum to the MPFC (common causal connectivity abnormalities). And distinct causal connectivity abnormalities (increased causal connectivity from the left thalamus to the MPFC in SCH than HC and DEP, and increased causal connectivity from the right cerebellum to the left thalamus in DEP than HC and SCH). In addition, the structural deficits in the MPFC and its causal connectivity from the cerebellum were associated with the negative symptom severity in SCH. This study found common/distinct structural deficits and aberrant causal connectivity patterns in the prefrontal-thalamic-cerebellar circuit in SCH and DEP, which may provide a potential direction for understanding the convergent and divergent psychiatric pathological mechanisms between SCH and DEP. Furthermore, concomitant structural and causal connectivity deficits in the MPFC may jointly contribute to the negative symptoms of SCH.