Emotional working memory in patients with major depressive disorder

Oxidative and Excitatory Neurotoxic Stresses in CRISPR/Cas9-Induced Kynurenine Aminotransferase Knockout Mice: A Novel Model for Despair-Based Depression and Post-Traumatic Stress Disorder

BACKGROUNDS

Memory and emotion are especially vulnerable to psychiatric disorders such as post-traumatic stress disorder (PTSD), which is linked to disruptions in serotonin (5-HT) metabolism. Over 90% of the 5-HT precursor tryptophan (Trp) is metabolized via the Trp-kynurenine (KYN) metabolic pathway, which generates a variety of bioactive molecules. Dysregulation of KYN metabolism, particularly low levels of kynurenic acid (KYNA), appears to be linked to neuropsychiatric disorders. The majority of KYNA is produced by the aadat (kat2) gene-encoded mitochondrial kynurenine aminotransferase (KAT) isotype 2. Little is known about the consequences of deleting the KYN enzyme gene.

METHODS

In CRISPR/Cas9-induced aadat knockout (kat2-/-) mice, we examined the effects on emotion, memory, motor function, Trp and its metabolite levels, enzyme activities in the plasma and urine of 8-week-old males compared to wild-type mice.

RESULTS

Transgenic mice showed more depressive-like behaviors in the forced swim test, but not in the tail suspension, anxiety, or memory tests. They also had fewer center field and corner entries, shorter walking distances, and fewer jumping counts in the open field test. Plasma metabolite levels are generally consistent with those of urine: antioxidant KYNs, 5-hydroxyindoleacetic acid, and indole-3-acetic acid levels were lower; enzyme activities in KATs, kynureninase, and monoamine oxidase/aldehyde dehydrogenase were lower, but kynurenine 3-monooxygenase was higher; and oxidative stress and excitotoxicity indices were higher. Transgenic mice displayed depression-like behavior in a learned helplessness model, emotional indifference, and motor deficits, coupled with a decrease in KYNA, a shift of Trp metabolism toward the KYN-3-hydroxykynurenine pathway, and a partial decrease in the gut microbial Trp-indole pathway metabolite.

CONCLUSIONS

This is the first evidence that deleting the aadat gene induces depression-like behaviors uniquely linked to experiences of despair, which appear to be associated with excitatory neurotoxic and oxidative stresses. This may lead to the development of a double-hit preclinical model in despair-based depression, a better understanding of these complex conditions, and more effective therapeutic strategies by elucidating the relationship between Trp metabolism and PTSD pathogenesis.

Relationship between low mood and micro-expression processing: evidence of negative bias in interpreting fleeting facial expressions

Depression affects the recognition of emotion in facial expressions by reducing the detection accuracy and adding a bias towards negativity. However, no study has examined associations between depression and the recognition of microfacial expressions (fleeting facial cues of emotions in people's faces). Thus, we investigated associations between low mood and micro-expression processing using video stimuli of micro-expressions. We examined whether (i) individuals with low mood had trouble recognizing emotions, (ii) were more likely to perceive happy facial expressions as neutral and neutral facial expressions as sad, and (iii) recognized sad emotional expressions better than control subjects (n = 349). We found that participants with low mood showed poorer performance when judging emotions in faces (p = 0.03). Furthermore, there was a specific deficit among them in recognizing happiness. Lastly, participants with low moods were more likely to perceive neutral faces as sad (p = 0.042). However, no evidence was found that individuals with low moods confused happy faces as neutral or were better than the control group at recognizing sad faces. Our results show that mood affects the perception of emotions in facial expressions, which has the potential to negatively affect interpersonal interactions and ultimately quality of life.

The effects of working memory training on attention deficit, adaptive and non-adaptive cognitive emotion regulation of Chinese children with Attention Deficit/Hyperactivity Disorder (ADHD)

BACKGROUND

Attention Deficit/Hyperactivity Disorder (ADHD) poses cognitive and emotional challenges for Chinese children. This study addresses the potential benefits of Working Memory Training for ADHD-affected children. Understanding its impact on Attention, cognitive regulation, and emotional responses is crucial for tailored interventions in the Chinese context. The Trial Registration Number (TRN) for this study is [TRN-2023-123,456], and it was officially registered on July 15, 2023, by Changchun Normal University.

OBJECTIVES

This study investigated how Working Memory training influences Attention, adaptive cognitive regulation, and non-adaptive cognitive emotion regulation in Chinese children with ADHD. It also assessed changes in attentional focus, improvements in adaptive cognitive regulation, and alterations in non-adaptive cognitive emotion regulation strategies.

METHODOLOGY

This quasi-experimental study aimed to assess the impact of working memory training on Chinese children with ADHD. Using pretest-posttest measures, 120 female students underwent Cogmed software training, targeting attention deficits and cognitive emotion regulation. Three reliable instruments measured outcomes. The procedure involved informed consent, questionnaires, 25 training sessions, and a two-month follow-up. Statistical analyses, including repeated measures ANOVA, assessed training effects.

RESULTS

ANOVA revealed a significant impact of Working memory training on attention deficit. Repeated measures ANOVA for cognitive emotion regulation indicated positive changes in adaptive and non-adaptive strategies over time, with sustained improvements in self-blame, rumination, catastrophizing, and blaming others. Bonferroni follow-up tests showed significant differences between pre-test, post-test, and follow-up, favoring the post-test and follow-up tests.

CONCLUSIONS

In summary, this research sheds light on the positive impact of memory training on Attention and cognitive emotion regulation in children with ADHD. The study underscores the potential of working memory interventions, particularly software-focused approaches, in enhancing attention levels and improving cognitive emotion regulation. The findings align with existing literature emphasizing the role of working memory deficits in ADHD.

IMPLICATIONS

Practically, incorporating memory training interventions into educational settings emerges as a viable strategy to support children with ADHD. This includes integrating memory training programs into both classroom activities and home-based interventions. Additionally, sustained implementation and long-term follow-up assessments are crucial for maximizing the effectiveness of memory training interventions. Tailoring interventions to specific ADHD subtypes and seamlessly integrating memory training activities into daily routines offer practical and personalized solutions for managing ADHD symptoms in diverse settings.

Relationship between physical activity and specific working memory indicators of depressive symptoms in university students

BACKGROUND

The detection rate of depression among university students has been increasing in recent years, becoming one of the main psychological diseases that endangers their physical and mental health. According to statistics, self-harm and suicide, for which there is no effective intervention, are the second leading causes of death.

AIM

To explore the relationship between different elements and levels of physical activity and college students' depression-symptom-specific working memory indicators.

METHODS

Of 143 college students were analyzed using the Beck Depression Self-Rating Scale, the Physical Activity Rating Scale, and the Working Memory Task.

RESULTS

There was a significant difference between college students with depressive symptoms and healthy college students in completing verbal and spatial working memory (SWM) tasks correctly (all P < 0.01). Physical Activity Scale-3 scores were significantly and positively correlated with the correct rate of the verbal working memory task (r = 0.166) and the correct rate of the SWM task (r = 0.210) (all P < 0.05). There were significant differences in the correct rates of verbal and SWM tasks according to different exercise intensities (all P < 0.05) and different exercise durations (all P < 0.05), and no significant differences in the correct rates of verbal and SWM tasks by exercise frequency (all P > 0.05).

CONCLUSION

An increase in physical exercise among college students, particularly medium- and high-intensity exercise and exercise of 30 min or more, can improve the correct rate of completing working memory tasks.

Memory performance mediates the relationship between depression and independence in instrumental activities of daily living among community-dwelling older adults: Evidence from the China Family Panel Study

Our objective was to examine the link between depression and independence in the instrumental activities of daily living (IADLs) and to explore the mediating role of memory performance through a cross-sectional analysis of a nationally representative sample of community-dwelling older adults in China. In total, 3730 respondents age ≥ 60 (51.7% males) from the 2020 survey of the China Family Panel Study (CFPS) constituted the study sample. Their depressive symptoms, memory performance, and independence in the IADLs were measured. Based on the descriptive statistics, bivariate correlation analysis and bootstrapping mediation analysis were conducted. As hypothesized, independence in the IADLs was negatively related to depression, while it was positively associated with memory performance. Moreover, after controlling for demographic factors, memory performance was demonstrated to be a partial mediator between depression and independence in the IADLs. These findings support the development of clinical interventions which prevent disability or maintain the physical functioning of older adults through alleviating depression and enhancing memory performance.

Associations between abnormal spontaneous neural activity and clinical variables, eye movements, and event-related potential indicators in major depressive disorder

Background

This study aimed to investigate the correlations between abnormal spontaneous neural activity measured with fractional amplitude of low-frequency fluctuations (fALFF) and clinical variables, eye movements, and event-related potential indicators in patients with major depressive disorder (MDD).

Methods

We recruited 42 patients with MDD and 42 healthy controls (HCs) and collected their clinical variables, eye movement, event-related potential, and resting-state functional magnetic resonance imaging (rs-fMRI) data. The fALFF, support vector machine (SVM), and correlation analysis were used to analyze the data.

Results

The results of the study showed that the fALFF values of the sensorimotor network, including the right middle temporal gyrus, right cerebellar Crus2, left occipital gyrus, and left middle temporal gyrus, were significantly higher compared to HCs. Correlation analysis showed that the abnormal fALFF value of the right cerebellar Crus2 was inversely correlated with the active coping scores of the Simplified Coping Style Questionnaire in the patients (r = -0.307, p = 0.048). No correlation was observed between abnormal fALFF values and other clinical symptoms, neuropsychological tests, eye movements, and event-related potential-related indicators in patients with MDD. fALFF values in the left middle temporal gyrus could be used to distinguish patients with MDD from HCs with an accuracy of 78.57%.

Conclusions

Patients with MDD exhibited enhanced spontaneous neural activity in the sensorimotor network. No associations were found between abnormal spontaneous neural activity and clinical variables, eye movements, and event-related potential related indicators in MDD.

Tai Chi exercise improves working memory capacity and emotion regulation ability

Purpose

The study aimed to research the promoting effects of Tai Chi exercise on working memory capacity and emotional regulation ability among college students.

Methods

Fifty-five participants were recruited and randomly divided into the Tai Chi group and control group. The Tai Chi group had a 12-week Tai Chi training to implement intervention, while the control group performed non-cognitive traditional sports with the same exercise intensity as the Tai Chi group. The visual 2-back test of action pictures and the Geneva emotional picture system test were performed before and after the trial, which aimed to examine whether the action memory of Tai Chi training can improve individuals' working memory capacity and emotion regulation ability.

Results

After 12 weeks, a significant difference was observed in Accuracy Rate (AR) (F = 54.89, p ≤ 0.001) and Response Time (RT) (F = 99.45, p ≤ 0.001) of individuals' Visual Memory Capacity between the Tai Chi group and the control group. Significant effects in Time (F = 98.62, p ≤ 0.001), Group (F = 21.43, p ≤ 0.001), and Interaction (Groups × time; F = 50.81, p ≤ 0.001) on Accuracy Rate (AR) of the Visual Memory Capacity were observed. The same effect was observed again on the Response Time (RT) of the Visual Memory Capacity, Time (F = 67.21, p ≤ 0.001), Group (F = 45.68, p ≤ 0.001), Interaction (groups × time; F = 79.52, p ≤ 0.001). Post-hoc analysis showed that at the end of 12 weeks, the participants in the Tai Chi group had significantly higher Visual Memory Capacity than those in the control group (p < 0.05).After 12 weeks, valence difference (F = 11.49, p ≤ 0.001), arousal difference (F = 10.17, p ≤ 0.01), and dominance difference (F = 13.30, p ≤ 0.001) in the emotion response were significantly different between the control group and the Tai Chi group. The effect of valence differences in Time (F = 7.28, p < 0.01), Group (F = 4.16, p < 0.05), and Time*Group (F = 10.16, p < 0.01), respectively, was significant in the Tai Chi group after 12-week intervention. Post hoc analysis showed valence swings in the Tai Chi group were significantly lower than that in the control group (p < 0.05); The effect of arousal difference in Time (F = 5.18, p < 0.05), Group (F = 7.26, p < 0.01), Time*Group (F = 4.23, p < 0.05), respectively, was significant in the Tai Chi group after 12-week intervention. Post hoc analysis showed arousal fluctuations in the Tai Chi group was significantly lower than that in the control group too (p < 0.01); As the same, the effect of dominance differences in Time (F = 7.92, p < 0.01), Group (F = 5.82 p < 0.05) and Time*Group (F = 10.26, p < 0.01), respectively was significant in the Tai Chi group. Dominance swings in the Tai Chi group were significantly lower than that in the control group (p < 0.001).

Conclusion

The data support our speculation that action memory training in Tai Chi exercise may improve individuals' working memory capacity, and then improve their emotion regulation ability, which has provided insightful information for customized exercise programs for emotion regulation in adolescents. Thus, we suggest those adolescents who are experiencing volatile moods and poor emotion regulation attend regular Tai Chi classes, which could contribute to their emotional health.

Association between WeChat Use and Memory Performance among Older Adults in China: The Mediating Role of Depression

Changes to memory performance in the course of aging may be influenced by behavioral factors. The use of social media among elderly people is increasing, but studying its effect on cognitive functions such as memory remains at an early stage of development. Meanwhile, the linking mechanisms underlying the association between social media use and memory performance, if any exist, have not been revealed. This study attempted to examine the association between the use of WeChat, the most popular social media platform in China, and memory performance among older people, and to test the possible mediating role of depression underlying this association. Data were drawn from the five-wave survey of the China Family Panel Study (CFPS), and 4929 respondents aged 60 or older (mean age = 68.19, SD = 5.84, 48.2% females) were included. Based on the descriptive statistics, the chi-squared test, Student’s t-test, correlation analysis, and mediation analysis were conducted. The results indicated that the usage rate of WeChat among the sample was 20.1%. After controlling for demographic variables, the use of WeChat was related to higher levels of memory performance and lower levels of depression. Moreover, depression partially mediated the relationship between WeChat use and memory performance. To maintain memory performance and promote cognitive health in the course of aging, using social media and alleviating depression merit special attention.

Widowhood Impairs Emotional Cognition Among Elderly

Background

The negative impacts of spousal bereavement on the emotional health of the elderly (e.g., depression and anxiety) have been revealed. However, whether widowhood impairs emotional cognition among the elderly is less known. The purpose of this study is to reveal the emotional cognitive deficits among the widowed elderly.

Methods

In this study, we recruited 44 widowed elderly (WE) and 44 elder couples (non-widowed elderly, NWE) and examined their emotional cognition including attention and visual working memory, which were measured by the visual search task and delayed-match-to-sample task, respectively. Three kinds of emotional faces (i.e., sad, angry, and happy) were adopted as the attentional or mnemonic targets.

Results

It revealed that WE had a general deficit in search efficiency across emotional types, while they showed mnemonic deficits in negative faces but not positive faces. Furthermore, the modeling analysis revealed that the level of depression or state anxiety of the elderly moderated the effects of widowhood on the deficits of mnemonic processing, i.e., the deficits were only evident among WE with the high level of depression or state anxiety.

Conclusion

These findings reveal the attentional deficits in sad, angry, and happy faces and the mnemonic deficits in sad and angry faces among elderly who suffer from widowhood and point out the important role of emotional problems such as depression and state anxiety in modulating these emotional cognitive deficits.

Social Media Usage, Working Memory, and Depression: An Experimental Investigation among University Students

Social media usage (SMU) and its relationship with working memory (WM) and academic performance remain unclear, and there is a lack of experimental evidence. We investigated whether WM mediates the association between SMU and academic performance, including the roles of depression, anxiety, and disordered social media use as possible contributors. A sample of 118 undergraduate students aged 19 to 28 from Saudi Arabia performed a WM test twice; for one assessment, participants were required to interact with social media before the test, and the other test was preceded by painting online. We also measured grade point average (GPA), habitual social media usage (SMU), depression (PHQ-9), anxiety (GAD-7), and disordered social media usage (SMDS). There was no significant difference between WM scores in the social media condition compared to the control condition, but when solely considering at least moderately depressed participants, social media use predicted significantly more errors in the social media condition compared to the control condition. Furthermore, higher SMDS scores were significantly predicted by higher PHQ-9 scores and more hours of habitual SMU. GPA scores were not predicted by WM performance or SMU. The present study is one of the first experimental attempts to compare the relationship between SMU and WM and highlights the priming effect of depression on the relationship between SMU and WM.

Increased functional interaction within frontoparietal network during working memory task in major depressive disorder

Abnormal fronto-parietal activation has been suggested as a neural underpinning of the working memory (WM) deficits in major depressive disorder (MDD). However, the potential interaction within the frontoparietal network during WM processing in MDD remains unclear. This study aimed to examine the role of abnormal functional interactions within frontoparietal network in the neuropathological mechanisms of WM deficits in MDD. A total of 40 MDD patients and 47 demographic matched healthy controls (HCs) were included. Functional magnetic resonance imaging and behavioral data were collected during numeric n-back tasks. The psychophysiological interaction and dynamic causal modelling methods were applied to investigate the connectivity within the frontoparietal network in MDD during n-back tasks. The psychophysiological interaction analysis revealed that MDD patients showed increased functional connectivity between the right inferior parietal lobule (IPL) and the right dorsolateral prefrontal cortex (dlPFC) compared with HCs during the 2-back task. The dynamic causal modelling analysis revealed that MDD patients had significantly increased forward modulation connectivity from the right IPL to the right dlPFC than HCs during the 2-back task. Partial correlation was used to calculate the relationship between connective parameters and psychological variables in the MDD group, which showed that the effective connectivity from right IPL to right dlPFC was correlated negatively with the sensitivity index d' of WM performances and positively with the depressive severity in MDD group. In conclusion, the abnormal functional and effective connectivity between frontal and parietal regions might contribute to explain the neuropathological mechanism of working memory deficits in major depressive disorder.

Dysregulation of Myt1 expression acts as a potential peripheral biomarker for major depressive disorder and bipolar disorder

Major depressive disorder (MDD) and bipolar disorder (BPD) are among the most debilitating mental conditions. Diagnostic criteria for MDD include psychological and physical symptoms, such as low mood and changes in appetite or sleep, respectively. BPD in addition to periods of depression represents episodes of mania or hypomania, and elevation in mood and energy levels are associated with this condition. Dysregulation in adult neurogenesis and myelination have been reported in psychiatric disorders. As a key factor in neurogenesis, it was hypothesized that Myt1 gene expression may be altered in these conditions. Using Real-time PCR, Myt1 expression level in 100 MDD patients and 100 BPD patients, compared with healthy control (HC) individuals was evaluated. Results demonstrate significant downregulation of Myt1 in MDD and BPD. Logistic regression analysis and binary classification evaluation reveal potential risk factor and biomarker characteristics of Myt1, respectively. Moreover, forward and backward digit span results denote a significant reduction in the function of working memory (WM) of MDD and BPD subjects. Correlation analysis revealed a significant association between Myt1 downregulation and WM disruption in the affected individuals. In conclusion, due to its altered role in neurogenesis, downregulation of Myt1 can be associated with the pathology of MDD and BPD.

Somatization Symptoms Regulate Emotional Memory Bias in Adolescents With Major Depressive Disorder

Objective: Somatization symptoms are commonly comorbid with depression. Furthermore, people with depression and somatization have a negative memory bias. We investigated the differences in emotional memory among adolescent patients with depressive disorders, with and without functional somatization symptoms (FSS). Methods: We recruited 30 adolescents with depression and FSS, 38 adolescents with depression but without FSS, and 38 healthy participants. Emotional memory tasks were conducted to evaluate the emotional memory of the participants in the three groups. The clinical symptoms were evaluated using the Hamilton Depression Rating Scale (HDRS) and the Children's Somatization Inventory (CSI). Results: The valence ratings and recognition accuracy rates for positive and neutral images of adolescent patients were significantly lower than those of the control group (F = 12.208, P < 0.001; F = 6.801, P < 0.05; F = 14.536, P < 0.001; F = 6.306, P < 0.05, respectively); however, the recognition accuracy rate for negative images of adolescent patients of depression without FSS was significantly lower than that of patients with FSS and control group participants (F = 10.316, P < 0.001). These differences persisted after controlling for HDRS scores. The within-group analysis revealed that patients of depression with FSS showed significantly higher recognition accuracy rates for negative images than the other types (F = 5.446, P < 0.05). The recognition accuracy rate for negative images was positively correlated with CSI scores (r = 0.352, P < 0.05). Conclusion: Therefore, emotional memory impairment exists in adolescent patients of depression and FSS are associated with negative emotional memory retention.

Decreased Response to Positive Facial Affect in a Depressed Cohort in the Dorsal Striatum During a Working Memory Task-A Preliminary fMRI Study

People with depression have shown alterations in processing emotional information and working memory functionality. There is some evidence that emotional content may interact with working memory update processes, however neurological correlates are current unknown. In this preliminary study we utilized a novel version of the emotional variant of the n-back working memory task in fMRI. We examined BOLD response of 14 healthy controls and 13 depressed participants in response to happy, sad, and neutral displays of facial affect. No accuracy or reaction time differences were found between the two groups. The depressed group showed significantly decreased BOLD response to happy faces compared to the control group areas of the dorsal striatum and anterior cingulate. Significant, moderate, positive associations were found between right caudate activation with anxiety score and anterior cingulate activation with depression score in those with depression. Our novel task was able to elicit group level differences in emotional processing during working memory update. These results suggest those with depression fail to differentiate between positive emotional stimuli and stimuli with no emotional content.