Auditory evoked potential could reflect emotional sensitivity and impulsivity

Colloidal Perovskite Nanocrystals for Blue-Light-Emitting Diodes and Displays

The evolution of display technology toward ultrahigh resolution, high color purity, and cost-effectiveness has generated interest in metal halide perovskites, particularly colloidal perovskite nanocrystals (PeNCs). PeNCs exhibit narrow emission spectra, high photoluminescence quantum yields, and wide color gamuts, rendering them promising candidates for next-generation displays. Despite significant advancements in perovskite light-emitting diode (PeLED) technology, challenges remain regarding the efficiencies of PeNC-based blue LEDs. Addressing these challenges, including both inherent and external instabilities of PeNCs and operational instabilities of the devices, is important as they collectively impede the broader acceptance and utilization of PeNCs. Herein, a comprehensive overview of the syntheses of dimension- and composition-controlled blue colloidal PeNCs and critical factors influencing the performances of colloidal PeNC-based blue LEDs is provided. Moreover, the advancements of colloidal PeNC-based blue LEDs and challenges associated with the application of these LEDs are explored, and the potentials of these LEDs for application in next-generation displays are emphasized. This review highlights the path forward for the future development of PeNC-based blue LEDs.

Loudness dependence of the auditory evoked potential: temporal stability, associations to sociodemographic variables, and functional significance-implications for clinical research

Introduction

The loudness dependence of the auditory evoked potential (LDAEP) has been suggested as a biomarker for central serotonergic function, and as such a proxy for serotonin related psychiatric symptomatology and intervention outcome, particularly in depression. This study aims to explore LDAEP characteristics in a large healthy population by assessing its test-retest reliability and examining associations with sociodemographic variables, psychological distress, and performance-based cognitive function.

Methods

Our sample included 100 healthy adults whose LDAEP was measured and correlated with age, sex, self-reported psychological distress, and cognitive performance.

Results

Participants examined twice (n = 38) showed high test-retest reliability with intraclass correlations (ICCs) between 0.67 and 0.89 over a 2-to-3-month interval. Furthermore, the magnitude of the LDAEP was significantly higher in women than men, and female hormonal contraceptive users exhibited higher LDAEP than non-users. In females, age was inversely correlated with LDAEP. However, no significant associations were found between LDAEP and measures of psychological distress, including depressive symptoms, nor with cognitive test performance.

Discussion

These results underline LDAEP's reliability as a biomarker over time, but also highlight age, sex and hormonal contraceptive use as significant factors influencing the LDAEP. Future research in clinical population should take these results into account, with an emphasis on providing the necessary sample sizes for relevant sub-group analyses.

Affective disorders and the loudness dependence of the auditory evoked potential: Serotonin and beyond

Identifying additional noninvasive biomarkers for affective disorders, such as unipolar major depressive disorder (MDD) and bipolar disorder (BD), could aid in the diagnosis and treatment of these prevalent and debilitating neuropsychiatric conditions. One such candidate biomarker is the loudness dependence of the auditory evoked potential (LDAEP), an event-related potential that measures responsiveness of the auditory cortex to different intensities of sound. The LDAEP has been associated with MDD and BD, including therapeutic response to particular classes of antidepressant drugs, while also correlating with several other neuropsychiatric disorders. It has been suggested that increased values of the LDAEP indicate low central serotonergic neurotransmission, further implicating this EEG measure in depression. Here, we briefly review the literature on the LDAEP in affective disorders, including its association with serotonergic signaling, as well as with that of other neurotransmitters such as dopamine. We summarize key findings on the LDAEP and the genetics of these neurotransmitters, as well as prediction of response to particular classes of antidepressants in MDD, including SSRIs versus noradrenergic agents. The possible relationship between this EEG measure and suicidality is addressed. We also briefly analyze acute pharmacologic studies of serotonin and/or dopamine precursor depletion and the LDAEP. In conclusion, the existing literature suggests that serotonin and norepinephrine may modulate the LDAEP in an opposing manner, and that this event-related marker may be of use in predicting response to chronic treatment with particular pharmacologic agents in the context of affective disorders, such as MDD and BD, including in the presence of suicidality.

Salmonella YqiC exerts its function through an oligomeric state

Protein oligomerization occurs frequently both in vitro and in vivo, with specific functionalities associated with different oligomeric states. The YqiC protein from Salmonella Typhimurium forms a homotrimer through its C-terminal coiled-coil domain, and the protein is closely linked to the colonization and invasion of the bacteria to the host cells. To elucidate the importance of the oligomeric state of YqiC in vivo and its relation with bacterial infection, we mutated crucial residues in YqiC's coiled-coil region and confirmed the loss of trimer formation using chemical crosslinking and size exclusion chromatography coupled with multiple angle light scattering (SEC-MALS) techniques. The yqiC-knockout strain complemented with mutant YqiC showed significantly reduced colonization and invasion of Salmonella to host cells, demonstrating the critical role of YqiC oligomerization in bacterial pathogenesis. Furthermore, we conducted a protein-protein interaction study of YqiC using a pulled-down assay coupled with mass spectrometry analysis to investigate the protein's role in bacterial virulence. The results reveal that YqiC interacts with subunits of Complex II of the electron transport chain (SdhA and SdhB) and the β-subunit of F0 F1 -ATP synthase. These interactions suggest that YqiC may modulate the energy production of Salmonella and subsequently affect the assembly of crucial virulence factors, such as flagella. Overall, our findings provide new insights into the molecular mechanisms of YqiC's role in S. Typhimurium pathogenesis and suggest potential therapeutic targets for bacterial infections.

Narcissism and central serotonergic neurotransmission in depression

OBJECTIVES

Based on previous research, it has been proposed that the development of depressive disorders is related to altered functioning of the serotonergic systems as well as the personality style, including narcissism. However, it is unclear to date how personality style, especially narcissism, depressive disorders and serotonergic activity are related.

METHODS

We included 74 patients with a depressive disorder (DP) and 74 healthy controls (HC) in the study. All participants completed the Personality Style and Disorder Inventory (PSDI) and the Beck Depression Inventory (BDI II). Moreover, we conducted EEG recordings for analysis of serotonergic neurotransmission by using the so-called intensity or loudness dependence of the auditory evoked potentials (LDAEP).

RESULTS

Significantly higher LDAEP results emerged for the DP group compared to the HC group, which indicated lower serotonergic activity in the patient's group. In addition, the positive correlation between ambitious-narcissistic personality and LDAEP reached significance in depressive patients.

LIMITATIONS

There was only a monocentric cross-sectional study with only one scale having differences between the two groups due to age and education.

CONCLUSIONS

Our data supports the theory of lower serotonergic activity in patients with depressive disorders and further suggests that high narcissistic personality traits are related to lower serotonergic neurotransmission in patients.

ER stress and inflammation crosstalk in obesity

The endoplasmic reticulum (ER) governs the proper folding of polypeptides and proteins through various chaperones and enzymes residing within the ER organelle. Perturbation in the ER folding process ensues when overwhelmed protein folding exceeds the ER handling capacity, leading to the accumulation of misfolded/unfolded proteins in the ER lumen-a state being referred to as ER stress. In turn, ER stress induces a gamut of signaling cascades, termed as the "unfolded protein response" (UPR) that reinstates the ER homeostasis through a panel of gene expression modulation. This type of UPR is usually deemed "adaptive UPR." However, persistent or unresolved ER stress hyperactivates UPR response, which ultimately, triggers cell death and inflammatory pathways, termed as "maladaptive/terminal UPR." A plethora of evidence indicates that crosstalks between ER stress (maladaptive UPR) and inflammation precipitate obesity pathogenesis. In this regard, the acquisition of the mechanisms linking ER stress to inflammation in obesity might unveil potential remedies to tackle this pathological condition. Herein, we aim to elucidate key mechanisms of ER stress-induced inflammation in the context of obesity and summarize potential therapeutic strategies in the management of obesity through maneuvering ER stress and ER stress-associated inflammation.

The Loudness Dependence of Auditory Evoked Potentials is associated with the Symptom Severity and Treatment in Boys with Attention Deficit Hyperactivity Disorder

Objective

Methods

Results

Conclusion

Association between the loudness dependence of auditory evoked potentials and age in patients with schizophrenia and depression

Objective

Although serotonergic dysfunction is significantly associated with major depressive disorder (MDD) and schizophrenia (SCZ), comparison of serotonergic dysfunction in both diseases has received little attention. Serotonin hypotheses have suggested diminished and elevated serotonin activity in MDD and SCZ, respectively. However, the foundations underlying these hypotheses are unclear regarding changes in serotonin neurotransmission in the aging brain. The loudness dependence of auditory evoked potentials (LDAEP) reflects serotonin neurotransmission. The present study compared the LDAEP between patients with SCZ or MDD and healthy controls (HCs). We further examined whether age was correlated with the LDAEP and clinical symptoms.

Methods

This prospective clinical study included 105 patients with SCZ (n = 54) or MDD (n = 51). Additionally, 35 HCs were recruited for this study. The LDAEP was measured on the midline channels via 62 electroencephalography channels.

Results

Patients with SCZ or MDD showed a significantly smaller mean LDAEP than those in HCs. The LDAEP was positively correlated with age in patients with SCZ or MDD.

Conclusions

Changes in central serotonergic activity could be indicated by evaluating the LDAEP in patients with SCZ or MDD. Age-related reductions in serotonergic activity may be screened using the LDAEP in patients with SCZ or MDD.

Investigation of the Serotonergic Activity and the Serotonin Content in Serum and Platelet, and the Possible Role of the Serotonin Transporter in Patients with Depression

According to the monoamine hypothesis, the development of depression is associated with dysfunctions of the serotonergic system. Alterations in the serotonin transporter gene (5-HTTLPR), the serotonergic activity in the brain, and the content of serotonin (5-HT) have been related to depression and were examined separately by previous studies. This study investigates these parameters in 89 depressed patients and 89 healthy participants. We investigated the serotonergic activity measured by the loudness dependence of auditory evoked potentials (LDAEP). In addition to the examination of the serotonin content (serum and platelet), enzyme-linked immunosorbent assays (ELISA) were used and 5-HTTLPR genotypes were analyzed. We observed a lower serotonin content in patients compared to healthy participants. Further, we noticed a correlation between anxiety and depression-associated symptoms with serotonergic activity. Patients treated with SSRI/SNRI showed decreased contents of serum serotonin compared to patients without any psychotropic medication or other psychotropic medications. Since the serotonergic activity, peripheral serotonin content, and 5-HTTLPR were unrelated, the results suggest independent alterations of central and peripheral serotonergic systems in depression. In line with this finding, serotonergic activity was related to anxiety and depression symptoms. Furthermore, the applied medication seems to influence serum serotonin content in patients with depression.

Alteration of cortical functional networks in mood disorders with resting-state electroencephalography

Studies comparing bipolar disorder (BD) and major depressive disorder (MDD) are scarce, and the neuropathology of these disorders is poorly understood. This study investigated source-level cortical functional networks using resting-state electroencephalography (EEG) in patients with BD and MDD. EEG was recorded in 35 patients with BD, 39 patients with MDD, and 42 healthy controls (HCs). Graph theory-based source-level weighted functional networks were assessed via strength, clustering coefficient (CC), and path length (PL) in six frequency bands. At the global level, patients with BD and MDD showed higher strength and CC, and lower PL in the high beta band, compared to HCs. At the nodal level, compared to HCs, patients with BD showed higher high beta band nodal CCs in the right precuneus, left isthmus cingulate, bilateral paracentral, and left superior frontal; however, patients with MDD showed higher nodal CC only in the right precuneus compared to HCs. Although both MDD and BD patients had similar global level network changes, they had different nodal level network changes compared to HCs. Our findings might suggest more altered cortical functional network in patients with BD than in those with MDD.

Electrophysiological Changes Related to Childhood Trauma in Patients with Major Depressive Disorder: An Event-related Potential Study

Objective

Methods

Results

Conclusion

Auditory event-related electroencephalographic potentials in borderline personality disorder

BACKGROUND

Borderline Personality Disorder (BPD) is characterized by mood dysregulation, impulsivity, identity disturbances, and a higher risk for suicide. Currently, the diagnosis is solely based on clinical observation of overt symptoms, and this can delay the detection of the disease and the timely start of appropriate treatment. Several candidate clinical tools have been studied to better characterize BPD, including event-related potentials (ERP). This review aimed at summarizing the results of the available ERP studies on BPD to clarify the possible application of this technique in the early diagnosis of BPD.

METHODS

A bibliographic search on PubMed and PsycInfo was performed in order to identify studies comprising individuals with BPD diagnosis and a control group that evaluated the ERP elicited by auditory stimuli.

RESULTS

Ten studies that explored various ERP components associated with auditory stimuli in BPD were included. Overall, the results showed that positive ERP (P50, P100, and P300) amplitude and latencies as well as loudness dependance were altered in BPD patients compared to controls, possibly reflecting deficits involving attention, mainly at its early stage, and executive functions.

LIMITATIONS

The reviewed studies used different ERP approaches and non-homogeneous BPD diagnostic criteria.

CONCLUSIONS

Auditory ERP appear to be a promising tool for the assessment of BPD patients, especially for early diagnosis and evaluation of cognitive symptoms.

Improved cognitive function in patients with major depressive disorder after treatment with vortioxetine: A EEG study

Introduction

Vortioxetine has a positive effect on cognitive function in patients with major depressive disorder (MDD). This study aimed to examine the changes in cognitive function and EEG (spectral power and mismatch negativity (MMN)) in patients with MDD pre‐ and postvortioxetine treatment.

Methods

Thirty patients with MDD were included in the study. They were given vortioxetine (10‐20mg po per day) for eight weeks. Depression and anxiety severities, social function (Korean version of the social adjustment scale (K‐SAS)), and cognitive function (digit‐symbol substitution Test (DSST), Korean version of the attentional control questionnaire (K‐ACQ), and Korean version of the perceived deficits questionnaire for depression (K‐PDQD)) were evaluated. Spectral power of EEG and MMN was also measured pre‐ and postvortioxetine treatment.

Results

Depression and anxiety severity, social function, and cognitive functioning significantly improved after vortioxetine treatment. Also, there was a significant decrease in the right central delta band and an increase in the right central beta 2 band following vortioxetine treatment. The changes in EEG spectral power were not related to changes in cognitive functions. Baseline MMN significantly predicted changes in DSST score after controlling for the baseline clinical variables.

Conclusion

Vortioxetine treatment improved cognitive function and induced changes in EEG (decreased theta power and increased beta power) in patients with MDD. Our results suggest that greater negative MMN amplitude is associated with greater potential for cognitive improvement following vortioxetine treatment.

BLURB FOR ETOC:Vortioxetine treatment improved cognitive function and induced changes in EEG (decreased theta power and increased beta power) in patients with MDD. Our results suggest that greater negative MMN amplitude is associated with greater potential for cognitive improvement following the vortioxetine treatment.

What Event-Related Potential Tells Us about Brain Function: Child-Adolescent Psychiatric Perspectives

Electroencephalography (EEG) measures neural activation due to various cognitive processes. EEG and event-related potentials (ERPs) are widely used in studies investigating psychopathology and neural substrates of psychiatric diseases in children and adolescents. The present study aimed to review recent ERP studies in child and adolescent psychiatry. ERPs are non-invasive methods for studying synaptic functions in the brain. ERP might be a candidate biomarker in child-adolescent psychiatry, considering its ability to reflect cognitive and behavioral functions in humans. For the EEG study of psychiatric diseases in children and adolescents, several ERP components have been used, such as mismatch negativity, P300, error-related negativity (ERN), and reward positivity (RewP). Regarding executive functions and inhibition in patients with attention-deficit/hyperactivity disorder (ADHD), P300 latency, and ERN were significantly different in patients with ADHD compared to those in the healthy population. ERN showed meaningful changes in patients with anxiety disorders, such as generalized anxiety disorder, separation anxiety disorder, and obsessive-compulsive disorder. Patients with depression showed significantly attenuated RewP compared to the healthy population, which was related to the symptoms of anhedonia.

Auditory evoked potentials and suicidal behaviors in patients with major depressive disorders

Loudness dependence of auditory evoked potentials (LDAEP) has been proposed as a biological marker of central serotonergic activity related to suicides. This study’s objective was to analyze the difference in LDAEP between depressed patients with suicide attempts (SA) and suicidal ideation (SI). It included 130 participants (45 depressed patients with SA, 49 depressed patients with SI, and 36 healthy controls) aged > 18 years who exhibited LDAEP during electroencephalography. Psychological characteristics and event-related potentials of the three groups were compared. There was no significant difference in LDAEP between major depressive disorder (MDD) patients with SA and SI (p = 0.59). MDD patients with SI, who attempted suicide had significantly lower LDAEP than healthy controls (p = 0.01 and p = 0.01, respectively). However, the significance disappeared when psychological characteristics were controlled. Our results suggest that LDAEP might not be possible biomarkers for suicidal behaviors in patients with MDD. Further studies to assess the biological basis of suicide and identify the underlying dimensions that mediate the relationship between the biological basis and suicidal behaviors will be needed.

Comparison of frontal alpha asymmetry among schizophrenia patients, major depressive disorder patients, and healthy controls

BACKGROUND

Electroencephalography (EEG) frontal alpha asymmetry (FAA) has been observed in several psychiatric disorders. Dominance in left or right frontal alpha activity remains inconsistent in patients with major depressive disorder (MDD), patients with schizophrenia, and healthy controls. This study compared FAA among patients with MDD and schizophrenia, and healthy controls.

METHODS

We recruited 20 patients with MDD, 18 patients with schizophrenia, and 16 healthy individuals. The EEG alpha frequency ranged from 8 Hz to 12 Hz. FAA was expressed as the difference between absolute power values of right and left hemisphere electrodes in the alpha frequency range (common-log-transformed frontal right- and left-hemisphere electrodes: F4-F3, F8-F7, FP2-FP1, AF4-AF3, F6-F5, and F2-F1). Hamilton depression and anxiety rating scales were evaluated in patients with MDD. Positive and negative syndrome scales were evaluated in patients with schizophrenia.

RESULTS

Patients with schizophrenia showed significantly lower left FAA than healthy controls (F4-F3, schizophrenia vs. healthy controls: - 0.10 ± 0.04 vs. -0.05 ± 0.05). There were no significant differences in FAA between patients with schizophrenia and MDD as well as between patients with MDD and healthy controls.

CONCLUSIONS

The present study suggests that FAA indicates a relatively lower activation of left frontal electrodes in schizophrenia. The left-lateralized FAA could be a neuropathological attribute in patients with schizophrenia, but a lack of sample size and information such as medication and duration of illness might obscure the interpretation and generalization of our findings. Thus, further studies to verify the findings would be warranted.

The relationship between sensory processing sensitivity and attention deficit hyperactivity disorder traits: A spectrum approach

The aim of the present study was to examine the relationship between sensory processing sensitivity (SPS) and symptoms of Attention Deficit Hyperactivity Disorder (ADHD) in adults. The Highly Sensitive Person Scale (HSPS) scale and the Adult ADHD Self-Report Scale (ASRS) were administered to a non-clinical group of 274 participants recruited from a university volunteers list. We found a highly significant positive correlation between number of self-reported ADHD traits and sensory sensitivity. Furthermore, ADHD traits and age were predictors of SPS and exploratory factor analysis revealed a factor that combined ADHD traits and items from the HSPS. The psychometric properties of the HSPS were also examined supporting the unidimensional nature of the concept. To our knowledge, this is the first study to identify a positive relationship between HSPS and ADHD traits in the general population. Our results further support recent findings suggesting abnormal sensory processing in ADHD.

The Relationship Between Response-Inhibitory Event-Related Potentials and Symptoms of Attention-Deficit/Hyperactivity Disorder in Adult Patients with Major Depressive Disorder

OBJECTIVE

Attention-deficit and poor impulse control have frequently been observed in major depressive disorder (MDD) and attention-deficit and hyperactivity disorder (ADHD). Altered event-related potential (ERP) performance, such as GoNogo tasks, has been regarded as a neurocognitive process associated with attention and behavioral inhibition. The aim of this study was to investigate the association between Nogo ERP and adult ADHD in MDD.

METHODS

A total of 64 participants with MDD (32 comorbid with ADHD) and 32 healthy controls aged 19-45 years were recruited; they performed GoNogo paradigms during electroencephalogram measurement. Beck Depression Inventory (BDI), State-Trait Anxiety Inventory (STAI), and the Adult ADHD Self-Report Scale (ASRS) were evaluated. Clinical measures and GoNogo ERP were compared between three groups: depression with ADHD, depression without ADHD, and healthy controls.

RESULTS

MDD subjects with ADHD showed significantly decreased Nogo P3 amplitude at frontal electrode, compared with those without ADHD and healthy controls. MDD subjects with ADHD showed significantly longer Nogo N2 latency at frontal and frontocentral electrodes, compared with those without ADHD and healthy controls. In MDD subjects with ADHD, the Nogo P3 amplitude at the frontal electrode was negatively correlated with the ASRS score and inattention. The Nogo N2 latency at the frontal electrode was positively correlated with false alarm rate.

CONCLUSION

The decreased Nogo P3 amplitude in the frontal area might be a potential biological marker for inattention in depressed patients with ADHD.

Associations of childhood experiences with event-related potentials in adults with autism spectrum disorder

Childhood maltreatment is defined as experiencing of physical, emotional and sexual abuse and neglect in childhood. Maltreatment in childhood leads to substantial psychosocial problems later in life in the general population. Individuals with autism spectrum disorder (ASD) have a higher risk of experiencing stressful and traumatic events, such as maltreatment, during childhood. Although childhood maltreatment reportedly leads to psychosocial problems in adults with ASD, the biological associations between childhood experiences and brain function in this population remain understudied. Here, we evaluated the relationships between childhood experiences and event-related potential (ERP) components during the auditory odd-ball task in adults with ASD (N = 21) and typically developed (TD) individuals (N = 22). We found that the higher the severity of sexual abuse, the larger the amplitude of P300 at Fz, Cz, C3, and C4 in individuals with ASD. Conversely, the severity of child maltreatment was associated with P300 latency at Cz and C3 in TD individuals. Moreover, full IQ was significantly associated with the MMN amplitude at Fz, Cz, C3, and C4 in TD individuals. These findings provide the first evidence that ERPs could be used to study the impacts childhood experiences on the brain of individuals with ASD and that childhood sexual abuse has salient impacts on brain function in this population.

Mismatch negativity indices and functional outcomes in unipolar and bipolar depression

The aim of the study was to explore the association between functional outcomes and mismatch negativity (MMN) activity in participants with mood disorders. The study participants were 27 subjects with major depressive disorder (MDD), 29 subjects with bipolar disorder (BD), and 33 healthy controls who performed a passive auditory oddball paradigm while electroencephalography (EEG) was recorded. Peak amplitudes and source activity of the MMN were compared across groups. Mood and anxiety symptoms were evaluated. The functional levels were the lowest in the BD group, followed by the MDD and healthy control groups. The subjects with BD had significantly lower MMN amplitudes at the frontal and frontocentral electrodes than the healthy controls. The source activity of the MMN from the left anterior cingulate cortex, inferior frontal gyrus, and middle frontal gyrus was significantly increased in the BD group compared to the MDD group. Significant correlations were detected between the functional outcomes and MMN amplitudes at frontal and frontocentral sites. The functional outcome was significantly correlated with left frontal regions. In conclusion, MMN activity appears to be a promising candidate as an evaluation tool for functional outcomes in mood disorders.

Prediction of Antidepressant Treatment Outcome Using Event-Related Potential in Patients with Major Depressive Disorder

(1) Background: Prediction of treatment outcome has been one of the core objectives in clinical research of patients with major depressive disorder (MDD). This study explored the possibility of event-related potential (ERP) markers to predict antidepressant treatment outcomes among MDD patients; (2) Methods: Fifty-two patients with MDD were recruited and evaluated through Hamilton depression (HAM-D), Hamilton anxiety rating scale (HAM-A), and CORE. Patients underwent a battery of ERP measures including frontal alpha symmetry (FAA) in the low alpha band (8–10 Hz), mismatch negativity (MMN), and loudness-dependent auditory evoked potentials (LDAEP); (3) Results: During the eight weeks of study, 61% of patients achieved remission, and 77% showed successful treatment responsiveness. Patients with low FAA in F5/F6 demonstrated a significantly higher remission/response ratio and better treatment responsiveness (F (2.560, 117.755) = 3.84, p = 0.016) compared to patients with high FAA. In addition, greater FAA in F7/F8 EEG channels was significantly associated with greater melancholia scores (r = 0.34, p = 0.018). Other ERP markers lacked any significant effect; (4) Conclusions: Our results suggested low FAA (i.e., greater left frontal activity) could reflect a good treatment response in MDD patients. These findings support that FAA could be a promising index in understanding both MDD and melancholic subtype.

Event-Related Potentials to Changes in Sound Intensity Demonstrate Alterations in Brain Function Related to Depression and Aging

Measures of the brain's automatic electrophysiological responses to sounds represent a potential tool for identifying age- and depression-related neural markers. However, these markers have rarely been studied related to aging and depression within one study. Here, we investigated auditory event-related potentials (ERPs) in the brain that may show different alterations related to aging and depression. We used an oddball condition employing changes in sound intensity to investigate: (i) sound intensity dependence; (ii) sensory gating; and (iii) change detection, all within a single paradigm. The ERPs of younger (18-40 years) and older (62-80 years) depressed female participants and age-matched non-depressed participants were measured. Intensity dependence was examined as the difference between N1 responses to repeated high- and low-intensity sounds, sensory gating as N1 responses to rare and repeated sounds, and change detection as indexed by the mismatch negativity (MMN). We found that intensity dependence was greater in older participants than younger ones, indicating effects related to aging but not to depression. For sensory gating, we found depression- and age-related alterations as increased N1 responses. No group differences were found for MMN. Although a sensory gating deficit was expected in older adults, this study is the first to demonstrate age-related overexcitability in sound intensity dependency. The results indicate that automatic brain responses to sound intensity changes are suitable for studying age- and depression-related neural markers but may not be sensitive enough to differentiate the effects of aging and depression.

Altered Cortical Functional Networks in Patients With Schizophrenia and Bipolar Disorder: A Resting-State Electroencephalographic Study

BACKGROUND

Pathologies of schizophrenia and bipolar disorder have been poorly understood. Brain network analysis could help understand brain mechanisms of schizophrenia and bipolar disorder. This study investigates the source-level brain cortical networks using resting-state electroencephalography (EEG) in patients with schizophrenia and bipolar disorder.

METHODS

Resting-state EEG was measured in 38 patients with schizophrenia, 34 patients with bipolar disorder type I, and 30 healthy controls. Graph theory based source-level weighted functional networks were evaluated: strength, clustering coefficient (CC), path length (PL), and efficiency in six frequency bands.

RESULTS

At the global level, patients with schizophrenia or bipolar disorder showed higher strength, CC, and efficiency, and lower PL in the theta band, compared to healthy controls. At the nodal level, patients with schizophrenia or bipolar disorder showed higher CCs, mostly in the frontal lobe for the theta band. Particularly, patients with schizophrenia showed higher nodal CCs in the left inferior frontal cortex and the left ascending ramus of the lateral sulcus compared to patients with bipolar disorder. In addition, the nodal-level theta band CC of the superior frontal gyrus and sulcus (cognition-related region) correlated with positive symptoms and social and occupational functioning scale (SOFAS) scores in the schizophrenia group, while that of the middle frontal gyrus (emotion-related region) correlated with SOFAS scores in the bipolar disorder group.

CONCLUSIONS

Altered cortical networks were revealed and these alterations were significantly correlated with core pathological symptoms of schizophrenia and bipolar disorder. These source-level cortical network indices could be promising biomarkers to evaluate patients with schizophrenia and bipolar disorder.

The relationship between auditory evoked potentials and symptoms of attention-deficit/hyperactivity disorder in adult patients with major depressive disorder

OBJECTIVES

Loudness dependence of auditory evoked potential (LDAEP) has been proposed as a biological marker for central serotonergic activity in depressive illness. A recent study has suggested that serotonin plays an important role in impulsivity and emotional sensitivity that are prominent clinical manifestations in attention deficit and hyperactivity disorder (ADHD). The objective of this study was to examine the association between LDAEP and ADHD symptoms in major depressive disorder (MDD).

METHODS

A total of 60 participants (40 subjects with MDD and 20 healthy controls) aged >18 years who had LDAEPs performed during electroencephalograms were included in this study. ADHD symptoms, depressive, and anxiety symptoms were evaluated. Psychological characteristics and event-related potentials (ERP) were compared among three groups: depression with ADHD symptoms, depression without ADHD symptoms, and healthy controls.

RESULTS

MDD subjects with ADHD symptoms (N = 20) showed significantly lower LDAEP levels than those without ADHD symptoms (N = 20) and healthy controls (N = 20). LDAEP differences between MDD subjects without ADHD symptoms and healthy controls were not statistically significant. In partial correlation analyses adjusted for age and sex, significant correlations of psychological scales of depression, ADHD symptoms, and LDAEPs were found.

CONCLUSION

Results of the present study suggest that LDAEP can reflect adult ADHD symptoms in MDD. Auditory evoked potential appears to be a promising candidate as an evaluation tool for inattention and poor impulse control as well as emotional sensitivity.

Mismatch Negativity and Cortical Thickness in Patients With Schizophrenia and Bipolar Disorder

INTRODUCTION

Mismatch negativity (MMN) is a measure of automatic neurophysiological brain processes for detecting unexpected sensory stimuli. This study investigated MMN reduction in patients with schizophrenia and bipolar disorder and examined whether cortical thickness is associated with MMN, for exploratory purposes.

METHODS

Electroencephalograms were recorded in 38 patients with schizophrenia, 37 patients with bipolar disorder, and 32 healthy controls (HCs) performing a passive auditory oddball paradigm. All participants underwent T1 structural magnetic resonance imaging scanning to investigate the cortical thickness of MMN-generating regions. Average MMN amplitudes from the frontocentral electrodes were analyzed.

RESULTS

Patients with schizophrenia and bipolar disorder exhibited significantly reduced MMN amplitude compared with HCs. In bipolar disorder, we found intermediate MMN amplitude among the groups. Average MMN and cortical thickness of the right superior temporal gyrus (STG) were significantly negatively correlated in patients with schizophrenia. In patients with bipolar disorder, average MMN was significantly correlated with cortical thickness of the left anterior cingulate cortex and the right STG. MMN showed negative correlations with social and occupational functioning in schizophrenia, and with the Korean auditory verbal learning test for delayed recall in bipolar disorder.

CONCLUSIONS

MMN reduction was associated with cortical thinning in frontal and temporal areas in patients, particularly with an auditory verbal hallucination-related region in schizophrenia and emotion-related regions in bipolar disorder. MMN was associated with functional outcomes in schizophrenia, whereas it was associated with neurocognition in bipolar disorder.

Cortical volume and 40-Hz auditory-steady-state responses in patients with schizophrenia and healthy controls

Background

Abnormalities in the 40-Hz auditory steady-state response (ASSR) of the gamma range have been reported in schizophrenia (SZ) and are regarded as important pathophysiological features. Many of the previous studies reported diminished gamma oscillations in SZ, although some studies reported increased spontaneous gamma oscillations. Furthermore, brain morphological correlates of the gamma band ASSR deficits have rarely examined. We investigated different measures of the 40-Hz ASSR and their association with brain volumes and psychological measures of SZ.

Methods

The 40-Hz ASSR was measured for 80 dB click sounds (1 ms, 500-ms trains at 40-Hz, with 3050 to 3500 inter-train interval) using electroencephalography with 64 electrodes in 33 patients with SZ (male: 16, female: 17 (age range: 21–60)) and 30 healthy controls (HCs) (male: 13, female: 17 (age range: 23–64)). Four gamma oscillation measures (evoked power, spontaneous oscillations (baseline and total power), and inter-trial phase coherence (ITC)) were assessed. The source activities of the ASSR were also analyzed. Brain volumes were assessed using high-resolution magnetic resonance imaging and voxel-based morphometry and superior temporal gyrus (STG) volume measures were obtained.

Results

Patients with SZ had larger total and evoked powers and higher ITC than HCs. Both groups showed significantly different association between mean evoked power and right STG volume. In HCs but not SZ, mean evoked power showed significant positive correlation with right STG volume. In addition, the two groups showed significantly different association between verbal fluency and mean evoked power. High evoked power was significantly correlated with poor verbal fluency in SZ.

Conclusions

The current study found increased gamma oscillation in SZ and suggests significant involvement of the STG in gamma oscillations.

•

SZ had larger total and evoked powers and higher ITC than HCs.

•

Evoked power positively correlated with right STG volume in HCs.

•

High evoked power correlated with poor verbal fluency in SZ.

The Role of Interpersonal Problems and Family Environment in the Association Between Impulsivity and Suicidal Ideation: A Moderate Mediation Model

Impulsivity, interpersonal problems, and family environment are important factors in the development of suicidal ideation, but the pathway of these factors on suicidal ideation is not clear. This study constructed a moderated mediation model to examine whether interpersonal problems mediated the relationship between impulsivity and suicidal ideation and whether this mediating process was moderated by family environment. For this purpose, 902 college students from Tianjin Normal University located in the north of China were recruited to participate in this study with Barratt Impulsiveness Scale, Adolescent Self-Rating Life Events Check List, Family Environment Scale, and Beck Scale for Suicidal Ideation. Impulsivity could significantly predict suicidal ideation, and the relationship between impulsivity and suicidal ideation was significantly mediated by interpersonal problems; furthermore, the mediating effect and the directing effect were significantly moderated by family environment. These findings contribute to our understanding of a comprehensive interpretation of both environmental and individual factors' impacts on suicidal ideation.

Dysfunctional frontal lobe activity during inhibitory tasks in individuals with childhood trauma: An event-related potential study

Background

Individuals who experience childhood trauma are vulnerable to various psychological and behavioral problems throughout their lifetime. This study aimed to investigate whether individuals with childhood trauma show altered frontal lobe activity during response inhibition tasks.

Methods

In total, 157 healthy individuals were recruited and instructed to perform a Go/Nogo task during electroencephalography recording. Source activities of N2 and P3 of Nogo event-related potentials (ERP) were analyzed. The Childhood Trauma Questionnaire (CTQ) and Barratt Impulsivity Scale (BIS) were applied. Individuals were divided into three groups based on their total CTQ score: low CTQ, middle CTQ, and high CTQ groups.

Results

The high CTQ group exhibited significantly higher BIS scores than the low CTQ group. P3 amplitudes of the differences between Nogo and Go ERP waves exhibited higher mean values in the low CTQ than the high CTQ group, with trending effects. In Nogo-P3, the source activities of the right anterior cingulate cortex, bilateral medial frontal cortex (MFC), bilateral superior frontal gyrus (SFG), and right precentral gyrus were significantly lower in the high CTQ than the low CTQ group. Motor impulsivity showed a significant negative correlation with activities of the bilateral MFC and SFG in Nogo-P3 conditions.

Conclusions

Our study revealed that individuals with childhood trauma have inhibitory failure and frontal lobe dysfunction in regions related to Nogo-P3.

Childhood Trauma Associated with Enhanced High Frequency Band Powers and Induced Subjective Inattention of Adults

Childhood trauma can lead to various psychological and cognitive symptoms. It has been demonstrated that high frequency electroencephalogram (EEG) powers could be closely correlated with inattention. In this study, we explored the relationship between high frequency EEG powers, inattention, symptoms of adult attention deficit hyperactivity disorder (ADHD), and childhood traumatic experiences. A total of 157 healthy Korean adult volunteers were included and divided into two groups using the Childhood Trauma Questionnaire (CTQ) score. The subjective inattention scores, ADHD scale, and anxiety and depression symptom were evaluated. EEG was recorded and quantitative band powers were analyzed. The results were as follows: (1) the high CTQ group showed significantly increased delta, beta1, beta2, beta3 and gamma, and significantly decreased low alpha power compared to the low CTQ group; (2) the high CTQ group had higher inattention score compared to the low CTQ group; (3) the high CTQ group had higher adult ADHD scores; (4) CTQ scores showed significant positive correlations with inattention scores, and adult ADHD scores; (5) unexpectedly, the inattention scores showed significant positive correlations with beta powers and a negative correlation with low alpha power; and (6) the moderated mediation model was confirmed: the depression fully mediated the path from state anxiety to inattention, and the CTQ significantly moderated the pathway between anxiety and depression. Our results show the possibility that childhood adversity may cause subjective inattention and adult ADHD symptoms. Depressive symptoms fully mediated the path from anxiety to inattention, especially in those who report severe childhood traumatic experiences.