Mechanisms of Memory Disruption in Depression

Memory, mood and associated neuroanatomy in individuals with steroid sulphatase deficiency (X-linked ichthyosis)

Steroid sulphatase (STS) cleaves sulphate groups from steroid hormones, and steroid (sulphate) levels correlate with mood and age-related cognitive decline. In animals, STS inhibition or deletion of the associated gene, enhances memory/neuroprotection and alters hippocampal neurochemistry. Little is known about the consequences of constitutive STS deficiency on memory-related processes in humans. We investigated self-reported memory performance (Multifactorial Memory Questionnaire), word-picture recall and recent mood (Kessler Psychological Distress Scale, K10) in adult males with STS deficiency diagnosed with the dermatological condition X-linked ichthyosis (XLI; n = 41) and in adult female carriers of XLI-associated genetic variants (n = 79); we compared results to those obtained from matched control subjects [diagnosed with ichthyosis vulgaris (IV, n = 98) or recruited from the general population (n = 250)]. Using the UK Biobank, we compared mood/memory-related neuroanatomy in carriers of genetic deletions encompassing STS (n = 28) and non-carriers (n = 34,522). We found poorer word-picture recall and lower perceived memory abilities in males with XLI and female carriers compared with control groups. XLI-associated variant carriers and individuals with IV reported more adverse mood symptoms, reduced memory contentment and greater use of memory aids, compared with general population controls. Mood and memory findings appeared largely independent. Neuroanatomical analysis only indicated a nominally-significantly larger molecular layer in the right hippocampal body of deletion carriers relative to non-carriers. In humans, constitutive STS deficiency appears associated with mood-independent impairments in memory but not with large effects on underlying brain structure; the mediating psychobiological mechanisms might be explored further in individuals with XLI and in new mammalian models lacking STS developmentally.

A novel biomarker of interleukin 6 activity and clinical and cognitive outcomes in depression

BACKGROUND

Inflammatory cytokines like interleukin-6 (IL-6) are implicated in depression, but most studies have hitherto focused on circulating levels of IL-6 rather than its activity. IL-6 trans-signalling is thought to be responsible for most of the pathogenic effects of IL-6 and is implicated in autoimmune diseases like rheumatoid arthritis. We tested the association between a multi-protein-derived measure of IL-6 trans-signalling and clinical and cognitive outcomes in patients with depression. We hypothesised that this novel measure of IL-6 activity/bioavailability would be associated with clinical and cognitive measures previously reported to be associated with inflammation in depression.

METHODS

Using data from 86 patients with International Classification of Diseases-10 diagnosis of depression, we calculated a ratio score representing IL-6 activity/bioavailability using serum IL-6, soluble IL-6 receptor (sIL-6R), and soluble glycoprotein 130 levels. We tested the relationship of this novel biomarker with 12 cytokines using correlation analyses and with cognitive and clinical measures using multivariable linear regression, following z-transformation of all immune exposures.

RESULTS

The novel measure of IL-6 activity/bioavailability was correlated with IL-6 (r=0.42, P=0.03), C-reactive protein (CRP) (r=0.42, P=0.03), sIL-6R (r=0.91, P<0.01), and tumour necrosis factor alpha (r=0.43, P=0.03). The IL-6 activity/bioavailability measure was associated with higher somatic symptoms of depression (β=1.09; 95% CI 0.30, 1.88; PFDR=0.01), fatigue (β=4.34; 95% CI 1.26, 7.42; PFDR=0.03), depression severity (β=3.06; 95% CI 0.71, 5.40; P=0.02), poorer quality of life (β=-0.07; 95% CI -0.13, -0.01; PFDR=0.045), and decreased psychomotor speed (β=-5.46; 95% CI -9.09, -1.84; PFDR=0.01),. There was little evidence of associations with reaction time, anhedonia, anxiety, emotional perception and recall, executive function, and sustained attention (Ps>0.05). The effect estimates for the associations of the novel measure with depression outcomes were comparable to those for individual immune proteins (i.e., IL-6, CRP, sIL-6R).

CONCLUSION

A novel multi-protein-derived measure of IL-6 activity/bioavailability shows robust associations with various inflammation-related clinical and cognitive outcomes in depression and performs well in comparison to single inflammatory proteins. We need replication of these findings in other samples, experiments for mechanistic validity of this novel biomarker, and clinical studies to assess its usefulness as a marker of illness risk and prognosis.

Unlocking new avenues for neuropsychiatric disease therapy: the emerging potential of Peroxisome proliferator-activated receptors as promising therapeutic targets

RATIONALE

Peroxisome proliferator-activated receptors (PPARs) are transcription factors that regulate various physiological processes such as inflammation, lipid metabolism, and glucose homeostasis. Recent studies suggest that targeting PPARs could be beneficial in treating neuropsychiatric disorders by modulating neuronal function and signaling pathways in the brain. PPAR-α, PPAR-δ, and PPAR-γ have been found to play important roles in cognitive function, neuroinflammation, and neuroprotection. Dysregulation of PPARs has been associated with neuropsychiatric disorders like bipolar disorder, schizophrenia, major depression disorder, and autism spectrum disorder. The limitations and side effects of current treatments have prompted research to target PPARs as a promising novel therapeutic strategy. Preclinical and clinical studies have shown the potential of PPAR agonists and antagonists to improve symptoms associated with these disorders.

OBJECTIVE

This review aims to provide an overview of the current understanding of PPARs in neuropsychiatric disorders, their potential as therapeutic targets, and the challenges and future directions for developing PPAR-based therapies.

METHODS

An extensive literature review of various search engines like PubMed, Medline, Bentham, Scopus, and EMBASE (Elsevier) databases was carried out with the keywords "PPAR, Neuropsychiatric disorders, Oxidative stress, Inflammation, Bipolar Disorder, Schizophrenia, Major depression disorder, Autism spectrum disorder, molecular pathway".

RESULT & CONCLUSION

Although PPARs present a hopeful direction for innovative therapeutic approaches in neuropsychiatric conditions, additional research is required to address obstacles and convert this potential into clinically viable and individualized treatments.

Common neural deficits across reward functions in major depression: a meta-analysis of fMRI studies

Major depressive disorder (MDD) is characterized by deficient reward functions in the brain. However, existing findings on functional alterations during reward anticipation, reward processing, and learning among MDD patients are inconsistent, and it was unclear whether a common reward system implicated in multiple reward functions is altered in MDD. Here we meta-analyzed 18 past studies that compared brain reward functions between adult MDD patients (N = 477, mean age = 26.50 years, female = 59.40%) and healthy controls (N = 506, mean age = 28.11 years, females = 55.58%), and particularly examined group differences across multiple reward functions. Jack-knife sensitivity and subgroup meta-analyses were conducted to test robustness of findings across patient comorbidity, task paradigm, and reward nature. Meta-regression analyses assessed the moderating effect of patient symptom severity and anhedonia scores. We found during reward anticipation, MDD patients showed lower activities in the lateral prefrontal-thalamus circuitry. During reward processing, patients displayed reduced activities in the right striatum and prefrontal cortex, but increased activities in the left temporal cortex. During reward learning, patients showed reduced activity in the lateral prefrontal-thalamic-striatal circuitry and the right parahippocampal-occipital circuitry but higher activities in bilateral cerebellum and the left visual cortex. MDD patients showed decreased activity in the right thalamus during both reward anticipation and learning, and in the right caudate during both reward processing and learning. Larger functional changes in MDD were observed among patients with more severe symptoms and higher anhedonia levels. The thalamic-striatal circuitry functional alterations could be the key neural mechanism underlying MDD patients overarching reward function deficiencies.

The mediating effect of depressive symptoms on the association between childhood friendship and physical function in middle-aged and older adults: Evidence from the China Health and Retirement Longitudinal Study (CHARLS)

BACKGROUND

This study examines the extent to which depressive symptoms mediate the link between childhood friendship (CF) and physical function among middle-aged and older adults in China.

METHODS

China Health and Retirement Longitudinal Study (CHARLS) data were used; specifically, CHARLS life history survey (conducted from June 1-December 31, 2014) and follow-up health survey (conducted from July 1-September 30, 2015) data were used. The Sobel test, Bootstrap test and multivariable logistic regression were performed to examine the mediating role of depressive symptoms (measured by the 10-item Center for Epidemiologic Studies Depression Scale) in the association between CF (measured by a standardized retrospective questionnaire) and physical function, which was measured by basic activities of daily living (BADL) disability, instrumental activities of daily living (IADL) disability, and grip strength.

RESULTS

A total of 12,170 participants aged 45 years or older were included in this cross-sectional study. After controlling for covariates, low-quality CF was associated with an increased prevalence of BADL disability (OR = 1.18; 95 % CI = 1.05-1.32), IADL disability (OR = 1.25; 95 % CI = 1.12-1.40), and low grip strength (OR = 1.21; 95 % CI = 1.09-1.34). The proportion of the mediating effect of depressive symptoms was 48 % for CF and BADL, 40 % for CF and IADL, and 11 % for CF and grip strength. Depressive symptoms and worse CF have a joint effect on BADL disability (OR = 3.30; 95 % CI = 2.82-3.85), IADL disability (OR = 3.52; 95 % CI = 3.03-4.09), and low grip strength (OR = 1.65; 95 % CI = 1.43-1.92).

LIMITATIONS

Not all potential confounding factors (such as childhood behavioural problems, genetic factors, and memory function) were measured in the analysis, and there may have been recall bias in the retrospective collection of CF data.

CONCLUSIONS

Individuals with high-quality CF were more likely to have a decreased prevalence of impaired physical function in later life. Depressive symptoms acted as a mediator associated with the development of CF.

Savoring mental imagery: Electrocortical effects and association with depression

The ability to focus on and increase positive emotion in response to mental imagery may play a key role in emotional wellbeing. Moreover, deficits in this ability might underlie emotional disorders such as depression. Here, we set out to determine whether people could use savoring to upregulate subjective and electrocortical response to mental imagery of previously viewed positive and neutral pictures, and whether this would be negatively affected by depression. On each trial, participants (N = 49) viewed a positive or neutral picture, prior to simply re-imagining the previously presented picture ("view") or re-imagining the picture while savoring it ("savor"). Results showed that savoring increased electrocortical and subjective response to imagined stimuli; however, this effect was only evident at the electrocortical level when controlling for depression. Moreover, depression moderated electrocortical findings, such that individuals who were more depressed showed a reduced effect of savoring on neural response to mental imagery. Results are in line with recent work that has shown the benefits of positive affect treatment for depression, to suggest that deficits in savoring mental imagery may play a role in the development and/or maintenance of depression.

Septohippocampal cholinergic system at the intersection of stress and cognition: Current trends and translational implications

Deficits in hippocampus-dependent memory processes are common across psychiatric and neurodegenerative disorders such as depression, anxiety and Alzheimer's disease. Moreover, stress is a major environmental risk factor for these pathologies and it exerts detrimental effects on hippocampal functioning via the activation of hypothalamic-pituitary-adrenal (HPA) axis. The medial septum cholinergic neurons extensively innervate the hippocampus. Although, the cholinergic septohippocampal pathway (SHP) has long been implicated in learning and memory, its involvement in mediating the adaptive and maladaptive impact of stress on mnemonic processes remains less clear. Here, we discuss current research highlighting the contributions of cholinergic SHP in modulating memory encoding, consolidation and retrieval. Then, we present evidence supporting the view that neurobiological interactions between HPA axis stress response and cholinergic signalling impact hippocampal computations. Finally, we critically discuss potential challenges and opportunities to target cholinergic SHP as a therapeutic strategy to improve cognitive impairments in stress-related disorders. We argue that such efforts should consider recent conceptualisations on the dynamic nature of cholinergic signalling in modulating distinct subcomponents of memory and its interactions with cellular substrates that regulate the adaptive stress response.

Association depressive symptoms with memory function and social capital before and during COVID-19 in community-dwelling older adults in rural Japan: A retrospective study with a longitudinal data

OBJECTIVES

This study aimed to investigate the impact of memory function and social capital on depressive symptoms during the COVID-19 pandemic among older adults in rural Japan.

METHODS

A retrospective study with longitudinal data was conducted during COVID-19 from May 2021 to November 2021 (T2) in Kurogawa, Japan. The candidate population for this study was 145 with the following requirements: (1) older individuals aged 65 years or above who were registered in the Kurogawa study, and (2) those with previous data (from November 2016 to February 2020; T1 as pre-pandemic). Memory function was assessed using the Wechsler Memory Scale-Revised Logical Memory II delayed recall part A (LM II-DR). Depressive symptoms were assessed using the Japanese version of the 15-item Geriatric Depression Scale (GDS-15). Social capital was evaluated through civic participation, social cohesion, and reciprocity. Fear of the COVID-19 infection (FCV-19S) was evaluated.

RESULTS

The final analysis included 96 participants (mean age = 81.0 years, SD = 4.8) Multivariate analysis for GDS-15 score by Mixed Model Repeated Measures (MMRM) revealed significant associations between LM II-DR (β = -0.13, 95% CI: -0.21-0.05, p = 0.002) and FCV-19S during COVID-19 (β = 0.08, 95% CI: 0.01-0.15, p = 0.02) with GDS-15 score. However, civic participation, social cohesion and reciprocity were not associated with GDS-15 score.

CONCLUSIONS

Among older adults in rural Japan, memory function and fear of the COVID-19 infection were significantly associated with depressive symptoms in MMRM analysis. However, social capital was not associated with depressive symptoms. This highlights the need to address memory function and fear of the COVID-19 infection in interventions for older adults during crises like the COVID-19 pandemic.

Altered asymmetry of functional connectome gradients in major depressive disorder

Introduction

Major depressive disorder (MDD) is a debilitating disease involving sensory and higher-order cognitive dysfunction. Previous work has shown altered asymmetry in MDD, including abnormal lateralized activation and disrupted hemispheric connectivity. However, it remains unclear whether and how MDD affects functional asymmetries in the context of intrinsic hierarchical organization.

Methods

Here, we evaluate intra- and inter-hemispheric asymmetries of the first three functional gradients, characterizing unimodal-transmodal, visual-somatosensory, and somatomotor/default mode-multiple demand hierarchies, to study MDD-related alterations in overarching system-level architecture.

Results

We find that, relative to the healthy controls, MDD patients exhibit alterations in both primary sensory regions (e.g., visual areas) and transmodal association regions (e.g., default mode areas). We further find these abnormalities are woven in heterogeneous alterations along multiple functional gradients, associated with cognitive terms involving mind, memory, and visual processing. Moreover, through an elastic net model, we observe that both intra- and inter-asymmetric features are predictive of depressive traits measured by BDI-II scores.

Discussion

Altogether, these findings highlight a broad and mixed effect of MDD on functional gradient asymmetry, contributing to a richer understanding of the neurobiological underpinnings in MDD.

Exploring the role of neuronal-enriched extracellular vesicle miR-93 and interoception in major depressive disorder

Major depressive disorder (MDD) is associated with interoceptive processing dysfunctions, but the molecular mechanisms underlying this dysfunction are poorly understood. This study combined brain neuronal-enriched extracellular vesicle (NEEV) technology and serum markers of inflammation and metabolism with Functional Magnetic Resonance Imaging (fMRI) to identify the contribution of gene regulatory pathways, in particular micro-RNA (miR) 93, to interoceptive dysfunction in MDD. Individuals with MDD (n = 41) and healthy comparisons (HC; n = 35) provided blood samples and completed an interoceptive attention task during fMRI. EVs were separated from plasma using a precipitation method. NEEVs were enriched by magnetic streptavidin bead immunocapture utilizing a neural adhesion marker (L1CAM/CD171) biotinylated antibody. The origin of NEEVs was validated with two other neuronal markers - neuronal cell adhesion molecule (NCAM) and ATPase Na+/K+ transporting subunit alpha 3 (ATP1A3). NEEV specificities were confirmed by flow cytometry, western blot, particle size analyzer, and transmission electron microscopy. NEEV small RNAs were purified and sequenced. Results showed that: (1) MDD exhibited lower NEEV miR-93 expression than HC; (2) within MDD but not HC, those individuals with the lowest NEEV miR-93 expression had the highest serum concentrations of interleukin (IL)-1 receptor antagonist, IL-6, tumor necrosis factor, and leptin; and (3) within HC but not MDD, those participants with the highest miR-93 expression showed the strongest bilateral dorsal mid-insula activation during interoceptive versus exteroceptive attention. Since miR-93 is regulated by stress and affects epigenetic modulation by chromatin re-organization, these results suggest that healthy individuals but not MDD participants show an adaptive epigenetic regulation of insular function during interoceptive processing. Future investigations will need to delineate how specific internal and external environmental conditions contribute to miR-93 expression in MDD and what molecular mechanisms alter brain responsivity to body-relevant signals.

The effects of slow wave sleep characteristics on semantic, episodic, and procedural memory in people with epilepsy

Slow wave sleep (SWS) is highly relevant for verbal and non-verbal/spatial memory in healthy individuals, but also in people with epilepsy. However, contradictory findings exist regarding the effect of seizures on overnight memory retention, particularly relating to procedural and non-verbal memory, and thorough examination of episodic memory retention with ecologically valid tests is missing. This research explores the interaction of SWS duration with epilepsy-relevant factors, as well as the relation of spectral characteristics of SWS on overnight retention of procedural, verbal, and episodic memory. In an epilepsy monitoring unit, epilepsy patients (N = 40) underwent learning, immediate and 12 h delayed testing of memory retention for a fingertapping task (procedural memory), a word-pair task (verbal memory), and an innovative virtual reality task (episodic memory). We used multiple linear regression to examine the impact of SWS duration, spectral characteristics of SWS, seizure occurrence, medication, depression, seizure type, gender, and epilepsy duration on overnight memory retention. Results indicated that none of the candidate variables significantly predicted overnight changes for procedural memory performance. For verbal memory, the occurrence of tonic-clonic seizures negatively impacted memory retention and higher psychoactive medication load showed a tendency for lower verbal memory retention. Episodic memory was significantly impacted by epilepsy duration, displaying a potential nonlinear impact with a longer duration than 10 years negatively affecting memory performance. Higher drug load of anti-seizure medication was by tendency related to better overnight retention of episodic memory. Contrary to expectations longer SWS duration showed a trend towards decreased episodic memory performance. Analyses on associations between memory types and EEG band power during SWS revealed lower alpha-band power in the frontal right region as significant predictor for better episodic memory retention. In conclusion, this research reveals that memory modalities are not equally affected by important epilepsy factors such as duration of epilepsy and medication, as well as SWS spectral characteristics.

Latent Profile Analysis of Suicidal Ideation in Chinese Individuals with Bipolar Disorder

Individuals with bipolar disorder (BD) have a greater suicide risk than the general population. In this study, we employed latent profile analysis (LPA) to explore whether Chinese individuals with different phases of BD differed at the levels of suicidal ideation. We recruited 517 patients. Depressive symptoms were measured using the 24-item Hamilton Depression Rating Scale (HAMD-24), and manic symptoms were evaluated using the Young Mania Rating Scale (YMRS). The extent of suicidal thoughts was determined through the Beck Scale for Suicide Ideation (BSSI). The scores of HAMD and YMRS were used to perform LPA. LPA categorized participants into three classes: one exhibiting severe depressive and mild manic symptomatology, another showing severe depressive and severe manic symptomatology, and the third one displaying severe depressive and intermediate manic symptomatology. Suicidal ideation levels were found to be remarkably elevated across all three classes. Additionally, the three classes showed no significant differences in terms of suicidal ideation. Our research confirms the link between depressive symptoms and suicide, independent of the manic symptoms. These findings carry meaning as they provide insight into the suicide risk profiles within different phases of BD.

Altered regional brain activity moderating the relationship between childhood trauma and depression severity

OBJECTIVE

Childhood trauma (CT) is a major environmental risk factor for an adverse course and treatment outcome of major depressive disorder (MDD). Evidence suggests that an altered regional brain activity may play a crucial role in the relationship between CT and MDD. This study aimed to clarify the relationship between CT, regional brain activity, and depression severity.

METHODS

In this study, 96 patients with MDD and 82 healthy controls (HCs) participated. Regional brain activity was measured using the fractional amplitude of low-frequency fluctuation (fALFF) and regional homogeneity (ReHo). These measures were compared between the MDD and HC groups, and the values of different brain regions were extracted as moderators.

RESULTS

Increased fALFF and ReHo values were observed in the left middle temporal gyrus in the MDD group compared with the HC group (p < 0.001). Furthermore, the fALFF and ReHo values moderated the positive correlation between the Childhood Trauma Questionnaire (CTQ) score, 17-item Hamilton Depression Rating Scale (HAMD-17) total score, and retardation factor score in the MDD group (all, p < 0.05). Finally, as the fALFF and ReHo values increased, the positive correlations between CTQ, HAMD-17 total, and retardation dimension scores became stronger.

CONCLUSION

Our study highlighted the crucial role of altered brain function in connecting childhood maltreatment with depressive symptoms. Our findings indicate that an altered regional brain activity could explain the potential neurobiological mechanisms of MDD symptoms, offering the opportunity to function as a powerful diagnostic biomarker.

The role of clinical and demographic predictors for understanding the cognitive impairment in Spinal Cord Injury (SCI) patients

STUDY DESIGN

Using a cross-sectional design, we extracted sociodemographic and clinical data from 488 Spinal Cord Injury (SCI) patients during their initial assessment before receiving intensive rehabilitation treatment.

OBJECTIVES

The primary objectives of this study were to ascertain the prevalence of cognitive impairment in the study sample and specify the key clinical and demographic predictors of cognitive functioning in SCI patients.

SETTING

Lucy Montoro Rehabilitation Institute (LMRI), University of Sao Paulo, Sao Paulo, Brazil.

METHODS

We utilized independent univariate and multivariate regression models with the Montreal Cognitive Assessment (MoCA) scale, adapted for individuals with visual impairment. Moreover, we consider scores from the execution tasks (visuospatial/executive) as the dependent variable.

RESULTS

Our findings demonstrate that approximately 80% of the evaluated study sample exhibited cognitive impairment. Through the multivariate regression models, we show that several factors, including age, education, depression levels, and the use of analgesics and/or opioids, are significant predictors of total cognitive scores. These factors are independent of the clinical features associated with SCI, such as age, sex, education, and time since the injury.

CONCLUSIONS

The results indicate a high prevalence of significant cognitive impairment within the sample, with age, education, depression levels, and the use of analgesics and/or opioids emerging as the primary predictors of total cognitive scores, independent of the clinical features correlated to SCI. These findings hold significant implications for both clinical research and practice, offering valuable guidance for comprehensive management throughout hospitalization and rehabilitation.

Altered intersubject functional variability of brain white-matter in major depressive disorder and its association with gene expression profiles

Major depressive disorder (MDD) is a clinically heterogeneous disorder. Its mechanism is still unknown. Although the altered intersubject variability in functional connectivity (IVFC) within gray-matter has been reported in MDD, the alterations to IVFC within white-matter (WM-IVFC) remain unknown. Based on the resting-state functional MRI data of discovery (145 MDD patients and 119 healthy controls [HCs]) and validation cohorts (54 MDD patients, and 78 HCs), we compared the WM-IVFC between the two groups. We further assessed the meta-analytic cognitive functions related to the alterations. The discriminant WM-IVFC values were used to classify MDD patients and predict clinical symptoms in patients. In combination with the Allen Human Brain Atlas, transcriptome-neuroimaging association analyses were further conducted to investigate gene expression profiles associated with WM-IVFC alterations in MDD, followed by a set of gene functional characteristic analyses. We found extensive WM-IVFC alterations in MDD compared to HCs, which were associated with multiple behavioral domains, including sensorimotor processes and higher-order functions. The discriminant WM-IVFC could not only effectively distinguish MDD patients from HCs with an area under curve ranging from 0.889 to 0.901 across three classifiers, but significantly predict depression severity (r = 0.575, p = 0.002) and suicide risk (r = 0.384, p = 0.040) in patients. Furthermore, the variability-related genes were enriched for synapse, neuronal system, and ion channel, and predominantly expressed in excitatory and inhibitory neurons. Our results obtained good reproducibility in the validation cohort. These findings revealed intersubject functional variability changes of brain WM in MDD and its linkage with gene expression profiles, providing potential implications for understanding the high clinical heterogeneity of MDD.

A randomized controlled trial of brief behavioral activation plus savoring for positive affect dysregulation in university students

Rising rates of depression on university campuses accentuate the need for specific intervention. Interventions targeting disturbances in positive affect, in particular, remain sparse, yet such deficits interfere substantially with functioning and further exacerbate or maintain negative symptoms. The current study aimed to evaluate the impact of a virtual, two-session Behavioral Activation augmented with Savoring (BA + S) intervention compared to an Emotional Awareness (EA) control group in increasing positive affect. Sixty university students with low positive affect were randomized to BA + S or EA and completed 21 days of experience-sampling of positive affect. Weekly measures of positive and negative valence symptoms were assessed at baseline, sessions one and two, and at one-week follow-up. Through a prori analyses utilizing multilevel and multivariate multilevel models, our results demonstrate that daily positive affect measured via experience-sampling significantly improved in BA + S, whereas positive affect did not change for those receiving EA, though the interaction of condition and time was not significant. Furthermore, interactions in weekly variables were significant. Increases in positive valence symptoms (affect, anhedonia, etc.) were only reported for students receiving BA + S but not EA. Negative valence symptoms (affect, depression, general distress) improved in both conditions but with superior improvements in BA + S compared to EA. BA + S shows promise for a scalable and accessible intervention to university students with clinical levels of positive and negative affect. ClinicalTrials ID: NCT05234476.

Interleukin-6 is correlated with amygdala volume and depression severity in adolescents and young adults with first-episode major depressive disorder

Inflammatory mechanisms may play crucial roles in the pathophysiology of major depressive disorder (MDD), and cytokine concentrations are correlated with brain alterations. Adolescents and young adults with MDD have higher recurrence and suicide rates than adults, but there has been limited research on the underlying mechanisms. In this study, we aimed to investigate the potential correlations among cytokines, depression severity, and the volumes of the amygdala, hippocampus, and nucleus accumbens in Han Chinese adolescents and young adults with first-episode MDD. Nineteen patients with MDD aged 10-21 years were enrolled from the Psychiatry Department of the First Affiliated Hospital of Chongqing Medical University, along with 18 age-matched healthy controls from a local school. We measured the concentrations of interleukin (IL)-4, IL-6, IL-8, and IL-10 in the peripheral blood, along with the volumes of the amygdala, hippocampus, and nucleus accumbens, as determined by magnetic resonance imaging. We observed that patients with MDD had higher concentrations of IL-6 and a trend towards reduced left amygdala and bilateral hippocampus volumes than healthy controls. Additionally, the concentration of IL-6 was correlated with the left amygdala volume and depression severity, while the left hippocampus volume was correlated with depression severity. This study suggests that inflammation is an underlying neurobiological change and implies that IL-6 could serve as a potential biomarker for identifying early stage MDD in adolescents and young adults.

Hippocampal subfield plasticity is associated with improved spatial memory

Physical exercise studies are generally underrepresented in young adulthood. Seventeen subjects were randomized into an intervention group (24.2 ± 3.9 years; 3 trainings/week) and 10 subjects into a passive control group (23.7 ± 4.2 years), over a duration of 6 months. Every two months, performance diagnostics, computerized spatial memory tests, and 3 Tesla magnetic resonance imaging were conducted. Here we find that the intervention group, compared to controls, showed increased cardiorespiratory fitness, spatial memory performance and subregional hippocampal volumes over time. Time-by-condition interactions occurred in right cornu ammonis 4 body and (trend only) dentate gyrus, left hippocampal tail and left subiculum. Increases in spatial memory performance correlated with hippocampal body volume changes and, subregionally, with left subicular volume changes. In conclusion, findings support earlier reports of exercise-induced subregional hippocampal volume changes. Such exercise-related plasticity may not only be of interest for young adults with clinical disorders of hippocampal function, but also for sedentary normal cohorts.

Glycitein prevents reserpine-induced depression and associated comorbidities in mice: modulation of lipid peroxidation and TNF-α levels

Depression is a debilitating mood disorder affecting millions worldwide and continues to pose a significant global health burden. Due to the multifaceted nature of depression, the current treatment regimens are not up to mark in terms of their multitargeting potential and least side effect profile. Molecules within the isoflavone class demonstrate promising potential in alleviating depression and associated conditions, offering a multifaceted approach to manage mental health concerns. Therefore, the current study was designed to explore the potential of glycitein, an isoflavone in managing reserpine-induced depression and associated comorbidities in mice. Reserpine (0.5 mg/kg; i.p.) administration for the first 3 days induced depression and associated comorbidities as evidenced by increased immobility time in forced swim test (FST) and tail suspension test (TST), along with reduced locomotor activity in the open field test (OFT) and increased latency to reach the platform in the Morris water maze (MWM) test. Reserpine treatment also upregulated and downregulated the brain thiobarbituric acid reactive substance (TBARS) and glutathione (GSH) levels, respectively. Furthermore, reserpine administration also uplifted the level of TNF-α in the serum samples. Glycitein (3 mg/kg and 6 mg/kg; p.o.) treatment for 5 days prevented the depressive effect of reserpine. It also improved the spatial memory at both dose levels. Moreover, in biochemical analysis, glycitein also reduced the brain TBARS and serum tumor necrosis factor-alpha (TNF-α) levels. Whereas, no significant effect was seen on the brain GSH level. Glycitein (6 mg/kg) was found to be more effective than the 3 mg/kg dose of glycitein. Overall results delineate that glycitein has the potential to manage depression and impaired memory by inhibiting lipid peroxidation and inflammatory stress.

Linkage of CDC42 and T-helper cell ratio with anxiety, depression and quality of life in ST-elevation myocardial infarction

Objective: To investigate the correlations between CDC42 and T-cell subsets concerning anxiety, depression and quality of life in ST-elevation myocardial infarction patients undergoing percutaneous coronary intervention. Methods: Sera from 156 participants were analyzed for CDC42 levels and Th1, Th2, Th17 and Treg cells. Results: CDC42 correlated with reduced Th1/Th2 and Th17/Treg ratios, lower anxiety and depression, and higher EuroQol visual analog scale (EQ-VAS) score. The Th17/Treg ratio correlated with elevated anxiety, depression, EuroQol-5 dimensions score and decreased EQ-VAS score. The Th1/Th2 ratio was positively related to the EQ-VAS score. Conclusion: CDC42 correlates with reduced Th1/Th2 and Th17/Treg ratios, reduced anxiety and depression, and improved quality of life in ST-elevation myocardial infarction patients undergoing percutaneous coronary intervention.

Prolonged stress response induced by chronic stress and corticosterone exposure causes adult neurogenesis inhibition and astrocyte loss in mouse hippocampus

Chronic stress is a pervasive and complex issue that contributes significantly to various mental and physical health disorders. Using the previously established chronic unpredictable stress (CUS) model, which simulates human stress situations, it has been shown that chronic stress induces major depressive disorder (MDD) and memory deficiency. However, this established model is associated with several drawbacks, such as limited research reproducibility and the inability to sustain stress response. To resolve these issues, we developed a new CUS model (CUS+C) that included exogenous corticosterone exposure to induce continuous stress response. Thereafter, we evaluated the effect of this new model on brain health. Thus, we observed that the use of the CUS+C model decreased body and brain weight gain and induced an uncontrolled coat state as well as depressive-like behavior in adult mice. It also impaired learning memory function and cognitive abilities, reduced adult hippocampal neurogenesis as well as the number of hippocampal astrocytes, and downregulated glial fibrillary acidic protein expression in the brains of adult mice. These findings can promote the utilization and validity of the animal stress model and provide new information for the treatment of chronic stress-induced depressive and memory disorders.

Persistence of symptoms and lung function in mild cases of COVID-19 six months after infection: a cross-sectional study

OBJECTIVES

To describe persistent symptoms and lung function in mild cases of COVID-19 six months after infection.

METHODS

Data collection was performed through a semi-structured questionnaire containing information on the participants' demographic and anthropometric data, the disease in the acute phase, and persistent symptoms six months after COVID-19 using spirometry and manovacuometry.

RESULTS

A total of 136 participants were evaluated, of whom 64% were male, with a mean age of 38.17 ± 14.08 years and a body mass index (BMI) of 29.71 ± 17.48 kg/m2. The main persistent symptoms reported were dyspnea on exertion (39.7%), memory loss (38.2%), and anxiety (48.5%). Considering lung function, the participants reached 88.87 ± 17.20% of the predicted forced vital capacity (FVC), 86.03 ± 22.01% of the forced expiratory volume in one second (FEV1), and 62.71 ± 25.04% of peak expiratory flow (PEF). Upon manovacuometry, 97.41 ± 34.67% of the predicted inspiratory force (Pimax) and 66.86 ± 22.97% of the predicted expiratory force (Pemax) were observed.

CONCLUSIONS

Six months after COVID-19 infection, a reduction in PEF and MEP was observed. Among the most commonly reported persistent symptoms were fatigue, tiredness with the slightest exertion, anxiety and depression, memory loss, and deficits in concentration.

Bayesian evaluation of diverging theories of episodic and affective memory distortions in dysphoria

People suffering from dysphoria retrieve autobiographical memories distorted in content and affect, which may contribute to the aetiology and maintenance of depression. However, key memory difficulties in dysphoria remain elusive because theories disagree how memories of different valence are altered. Here, we assessed the psychophysiological expression of affect and retrieved episodic detail while participants with dysphoria (but without a diagnosed mental illness) and participants without dysphoria relived positive, negative, and neutral memories. We show that participants with dysphoria retrieve positive memories with diminished episodic detail and negative memories with enhanced detail, compared to participants without dysphoria. This is in line with negativity bias but not overgeneral memory bias theories. According to confirmatory analyses, participants with dysphoria also express diminished positive affect and enhanced negative affect when retrieving happy memories, but exploratory analyses suggest that this increase in negative affect may not be robust. Further confirmatory analyses showed that affective responses to memories are not related to episodic detail and already present during the experience of new emotional events. Our results indicate that affective memory distortions may not emerge from mnemonic processes but from general distortions in positive affect, which challenges assumptions of memory theories and therapeutics. Protocol registration: The Stage 1 protocol for this Registered Report was accepted in principle on the 18rd of March 2021. The protocol, as accepted by the journal, can be found at https://doi.org/10.6084/m9.figshare.14605374.v1 .

Interval Timing as a Computational Pathway From Early Life Adversity to Affective Disorders

Adverse early life experiences can have remarkably enduring negative consequences on mental health, with numerous, varied psychiatric conditions sharing this developmental origin. Yet, the mechanisms linking adverse experiences to these conditions remain poorly understood. Here, we draw on a principled model of interval timing to propose that statistically optimal adaptation of temporal representations to an unpredictable early life environment can produce key characteristics of anhedonia, a transdiagnostic symptom associated with affective disorders like depression and anxiety. The core observation is that early temporal unpredictability produces broader, more imprecise temporal expectations. As a result, reward anticipation is diminished, and associative learning is slowed. When agents with such representations are later introduced to more stable environments, they demonstrate a negativity bias, responding more to the omission of reward than its receipt. Increased encoding of negative events has been proposed to contribute to disorders with anhedonia as a symptom. We then examined how unpredictability interacts with another form of adversity, low reward availability. We found that unpredictability's effect was most strongly felt in richer environments, potentially leading to categorically different phenotypic expressions. In sum, our formalization suggests a single mechanism can help to link early life adversity to a range of behaviors associated with anhedonia, and offers novel insights into the interactive impacts of multiple adversities.

The abnormal brain activation pattern of adolescents with major depressive disorder based on working memory tasks: A fNIRS study

OBJECTIVE

Although studies have confirmed that working memory (WM) is impaired among adults with major depressive disorder (MDD), generalizing these neurocognitive impairments to adolescents with MDD would be tenuous. Therefore, separate studies for adolescents with MDD are needed. Relatively little is known about the neural processes associated with WM dysfunction in adolescents with MDD. Thus, we examined whether adolescents with MDD have abnormal brain activation patterns compared to healthy controls (HC) during WM tasks and whether it was possible to distinguish adolescents with MDD and HC based on mean oxy-hemoglobin (Oxy-Hb) changes.

METHOD

A total of 87 adolescents with MDD and 63 HC were recruited. Functional near-infrared spectroscopy (fNIRS) was performed to monitor the concentrations of Oxy-Hb in the frontotemporal lobe while participants performed three WM tasks in order to examine WM impairments in adolescents with depression.

RESULTS

The mean changes in Oxy-Hb concentrations in the left prefrontal cortex and right prefrontal cortex were higher among HC than among patients during the encoding and maintenance phase under each WM-load task. Machine learning was used to distinguish adolescents with MDD and HC based on Oxy-Hb changes, with a moderate area under the curve of 0.84.

CONCLUSIONS

This study revealed WM defects in adolescents with MDD compared to HC based on mean Oxy-Hb changes, which can be valuable for distinguishing adolescents with MDD from HC.

Predicting depression in old age: Combining life course data with machine learning

With ageing populations, understanding life course factors that raise the risk of depression in old age may help anticipate needs and reduce healthcare costs in the long run. We estimate the risk of depression in old age by combining adult life course trajectories and childhood conditions in supervised machine learning algorithms. Using data from the Survey of Health, Ageing and Retirement in Europe (SHARE), we implement and compare the performance of six alternative machine learning algorithms. We analyse the performance of the algorithms using different life-course data configurations. While we obtain similar predictive abilities between algorithms, we achieve the highest predictive performance when employing semi-structured representations of life courses using sequence data. We use the Shapley Additive Explanations method to extract the most decisive predictive patterns. Age, health, childhood conditions, and low education predict most depression risk later in life, but we identify new predictive patterns in indicators of life course instability and low utilization of dental care services.

Protection of p-Coumaric acid against chronic stress-induced neurobehavioral deficits in mice via activating the PKA-CREB-BDNF pathway

There is a body of evidence to suggest that chronic stress modulates neurochemical homeostasis, alters neuronal structure, inhibits neurogenesis and contributes to development of mental disorders. Chronic stress-associated mental disorders present common symptoms of cognitive impairment and depression with complex disease mechanisms. P-coumaric acid (p-CA), a natural phenolic compound, is widely distributed in vegetables, cereals and fruits. p-CA exhibits a wide range of health-related effects, including anti-oxidative-stress, anti-mutagenesis, anti-inflammation and anti-cancer activities. The current study aims to evaluate the therapeutic potential of p-CA against stress-associated mental disorders. We assessed the effect of p-CA on cognitive deficits and depression-like behavior in mice exposed to chronic restraint stress (CRS); we used network pharmacology, biochemical and molecular biological approaches to elucidate the underlying molecular mechanisms. CRS exposure caused memory impairments and depression-like behavior in mice; p-CA administration attenuated these CRS-induced memory deficits and depression-like behavior. Network pharmacology analysis demonstrated that p-CA was possibly involved in multiple targets and a variety of signaling pathways. Among them, the protein kinase A (PKA) - cAMP-response element binding protein (CREB) - brain derived neurotrophic factor (BDNF) signaling pathway was predominant and further characterized. The levels of PKA, phosphorylated CREB (pCREB) and BDNF were significantly lowered in the hippocampus of CRS mice, suggesting disruption of the PKA-CREB-BDNF signaling pathway; p-CA treatment restored the signaling pathway. Furthermore, CRS upregulated expression of proinflammatory cytokines in hippocampus, while p-CA reversed the CRS-induced effects. Our findings suggest that p-CA will offer therapeutic benefit to patients with stress-associated mental disorders.

Revisiting the ownership effect in adults with and without autism

Self-owned items are better remembered than other-owned items; this ownership effect reflects privileged processing of self-related information. The size of this ownership effect has been shown to decrease in neurotypical adults as the number of autistic traits increases, and is reduced in autistic adults. However, emerging evidence has questioned the reliability of these findings. This paper aimed to replicate previous work using well-powered, pre-registered designs, and Bayesian analyses. Experiment 1 (N = 100) found a significant ownership effect in neurotypical adults; however, the size of this was unrelated to individual differences in autistic traits. Experiment 2 (N = 56) found an ownership effect in neurotypical but not autistic adults. The findings suggest that individual differences in autistic traits in the neurotypical population do not impact the ownership effect, but a clinical diagnosis of autism might. We discuss how these findings can be explained by differences in psychological self-awareness in autism.

The efficacy of electroencephalography neurofeedback for enhancing episodic memory in healthy and clinical participants: A systematic qualitative review and meta-analysis

Several studies have examined whether electroencephalography neurofeedback (EEG-NF), a self-regulatory technique where an individual receives real-time feedback on a pattern of brain activity that is theoretically linked to a target behaviour, can enhance episodic memory. The aim of this research was to i) provide a qualitative overview of the literature, and ii) conduct a meta-analysis of appropriately controlled studies to determine whether EEG-NF can enhance episodic memory. The literature search returned 46 studies, with 21 studies (44 effect sizes) meeting the inclusion criteria for the meta-analysis. The qualitative overview revealed that, across EEG-NF studies on both healthy and clinical populations, procedures and protocols vary considerably and many studies were insufficiently powered with inadequate design features. The meta-analysis, conducted on studies with an active control, revealed a small-size, significant positive effect of EEG-NF on episodic memory performance (g = 0.31, p = 0.003), moderated by memory modality and EEG-NF self-regulation success. These results are discussed with a view towards optimising EEG-NF training and subsequent benefits to episodic memory.

Mood-congruent memory revisited

Affective experiences are commonly represented by either transient emotional reactions to discrete events or longer term, sustained mood states that are characterized by a more diffuse and global nature. While both have considerable influence in shaping memory, their interaction can produce mood-congruent memory (MCM), a psychological phenomenon where emotional memory is biased toward content affectively congruent with a past or current mood. The study of MCM has direct implications for understanding how memory biases form in daily life, as well as debilitating negative memory schemas that contribute to mood disorders such as depression. To elucidate the factors that influence the presence and strength of MCM, here we systematically review the literature for studies that assessed MCM by inducing mood in healthy participants. We observe that MCM is often reported as enhanced accuracy for previously encoded mood-congruent content or preferential recall for mood-congruent autobiographical events, but may also manifest as false memory for mood-congruent lures. We discuss the relevant conditions that shape these effects, as well as instances of mood-incongruent recall that facilitate mood repair. Further, we provide guiding methodological and theoretical considerations, emphasizing the limited neuroimaging research in this area and the need for a renewed focus on memory consolidation. Accordingly, we propose a theoretical framework for studying the neural basis of MCM based on the neurobiological underpinnings of mood and emotion. In doing so, we review evidence for associative network models of spreading activation, while also considering alternative models informed by the cognitive neuroscience literature of emotional memory bias. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Emotion regulation during encoding reduces negative and enhances neutral mnemonic discrimination in individuals with depressive symptoms

Individuals with depression exhibit dysfunctional emotion regulation, general episodic memory deficits, and a negativity bias, where negative experiences are better remembered. Recent work suggests that the negativity bias in depression may be driven by enhanced mnemonic discrimination, a memory measure that relies on hippocampal pattern separation - a computation that processes experiences with overlapping features as unique. Previously, we found that individuals with depressive symptoms show enhanced negative and impaired neutral mnemonic discrimination. The current study aimed to investigate emotion regulation as an approach toward modifying memory encoding of negative and neutral events in individuals with depressive symptoms. Here we show that applying psychological distancing (a cognitive reappraisal strategy characterized by taking a third-person perspective toward negative events) during encoding was associated with reduced negative and enhanced neutral mnemonic discrimination during retrieval in individuals with depressive symptoms. These results suggest that applying emotion regulation techniques during encoding may provide an effective approach toward altering dysfunctional memory in those with depressive symptoms. Given that pharmacological treatments often fail to treat depression, emotion regulation provides a powerful and practical approach toward modifying cognitive and emotional processes. Future neuroimaging studies will be important to determine how emotion regulation impacts the neural mechanisms underlying these findings.

Aberrant neural network activation during reliving of autobiographical memories in adolescent depression

BACKGROUND

Adolescents with depression exhibit negative biases in autobiographical memory with detrimental consequences for their self-concept and well-being. Investigating how adolescents relive positive autobiographical memories and activate the underlying neural networks could reveal mechanisms that drive such biases. This study investigated neural networks when reliving positive and neutral memories, and how neural activity is modulated by valence and vividness in adolescents with and without depression.

METHODS

Adolescents (N = 69; n = 17 with depression) retrieved positive and neutral autobiographical memories. On a separate day, they relived these memories during fMRI scanning, and reported on pleasantness and vividness after reliving each memory. We used a multivariate, data-driven approach - event-related independent component analysis (eICA) - to characterize neural networks supporting autobiographical recollection.

RESULTS

Adolescents with depression reported their positive memories as significantly less pleasant compared to healthy controls, while subjective vividness was unaffected. Using eICA, we identified a broad autobiographical memory network, and subnetworks related to reliving positive vs neutral memories. These subnetworks comprised a 'self-referential processing network' including medial prefrontal cortex, posterior cingulate cortex/precuneus, and temporoparietal junction, anti-correlating with parts of the central executive network and salience network. Adolescents with depression exhibited aberrant activation in this self-referential network, but only when reliving relatively 'low' pleasant memories.

CONCLUSIONS

Our findings provide first insights into how the quality of reliving autobiographical memories in adolescents with depression may relate to aberrant self-referential neural network activation, and underscore the potential of targeting memory reliving in therapeutic interventions to foster self-esteem and diminish depressive symptoms.

Alterations of learning and memory are accompanied by alterations in the expression of 5-HT receptors, glucocorticoid receptor and brain-derived neurotrophic factor in different brain regions of an animal model of depression generated by neonatally male treatment with clomipramine in male rats

Depressive illness has been associated with impaired cognitive processes accompanied by reduced neurotrophin levels, especially brain-derived neurotrophic factor (BDNF), and dysfunctions in the hypothalamic-pituitary-adrenal (HPA) axis. In addition, depression is characterized by a decreased functioning of the serotonergic system due to changes in the activity or expression of its receptors including, most significantly, 5-HT1A, 5-HT2A, and 5-HT3 in brain regions that regulate mood, emotions, and memory, such as the prefrontal cortex, hippocampus, and amygdala. In this regard, rats treated with clomipramine (CMI) in the neonatal stage show depression-like behaviors that persist into adulthood; hence, this constitutes an adequate model of depression for exploring various molecular aspects associated with the etiology of this disorder. This, study, then, was designed to analyze the long-term effects of early postnatal exposure to CMI on the expression of 5-HT1A, 5-HT2A, and 5-HT3 receptors, as well as BDNF and GR in the following brain regions: PFC, amygdala, hippocampus, and hypothalamus, which could be related to alterations in memory and learning, as evaluated using the novel object recognition (NOR) and Morris water maze (MWM). Expression of the 5-HT1A, 5-HT2A, and 5-HT3 receptors, BDNF, and the glucocorticoid receptor (GR) was assessed by RT-qPCR in the four aforementioned brain regions, all of which play important roles in the control of memory and mood. Findings show that neonatal treatment with CMI causes alterations in memory and learning, as indicated by alterations in the results of the MWM and NOR tests. Expression of the 5-HT1A receptor increased in the hippocampus, amygdala, and hypothalamus, but decreased in the PFC, while the 5-HT2A and BDNF receptors decreased their expression in the PFC, amygdala, and hippocampus. There was no change in the expression of the 5-HT3 receptor. In addition, expression of GR in the hippocampus and PFC was low, but increased in the hypothalamus. Taken together, these data show that neonatal CMI treatment produces permanent molecular changes in brain regions related to learning and memory that could contribute to explaining the behavioral alterations observed in this model.

Prospective longitudinal associations between adverse childhood experiences and adult mental health outcomes: a protocol for a systematic review and meta-analysis

BACKGROUND

Research cites a strong, dose-response relationship between adverse childhood experiences (ACEs) and poor adult mental health outcomes including anxiety, depression, post-traumatic stress disorder (PTSD), self-harm, suicidality, and psychotic-like experiences.

AIM

To systematically investigate the existence and strength of association between ACEs and adult mental health outcomes in prospective longitudinal studies. The review will focus on the outcomes: anxiety, depression, PTSD, self-harm, suicidal ideation, and psychotic-like experiences.

METHODS

Twelve electronic databases will be searched: Embase, PsycINFO, MEDLINE, and Global Health through the OVID interface. ProQuest will be used to search Public Affairs Information Service (PAIS), Dissertations and Theses, Sociology Database (including Sociological Abstracts and Social Services Abstracts), PTSDpubs (formerly The Published International Literature on Traumatic Stress (PILOTS) Database) and Applied Social Sciences Index and Abstracts (ASSIA). CINAHL, World Health Organisation (WHO) Global Index Medicus, and WHO Violence Info will also be searched. Eligible studies will be double screened, assessed, and their data will be extracted. Any disagreement throughout these processes will be settled by a third reviewer. If enough studies meet the criteria and the methodological quality of each study is sufficient, a meta-analysis will be conducted.

ANALYSIS

A narrative synthesis of included studies and the associations between ACEs and adult mental health will be completed. If the number of studies included per mental health outcome is two or more, a multi-level meta-analysis will be completed using odds ratio effect sizes as outcomes.

DISCUSSION

This review will contribute to the existing body of literature supporting the long-term effects of ACEs on adult mental health. This review adds to previous reviews that have either synthesised cross-sectional associations between ACEs and mental health outcomes, synthesised longitudinal studies exploring the effect of ACEs on different physical and mental health outcomes or synthesised longitudinal studies exploring the effect of ACEs on the same mental health outcomes using different methods. This review aims to identify methodological weaknesses and knowledge gaps in current literature that can be addressed in future primary studies.

SYSTEMATIC REVIEW REGISTRATION

This protocol has been registered in PROSPERO (CRD42021297882).

Utility of pharmacogenetic testing to optimise antidepressant pharmacotherapy in youth: a narrative literature review

Pharmacogenetics (PGx) is the study and application of how interindividual differences in our genomes can influence drug responses. By evaluating individuals' genetic variability in genes related to drug metabolism, PGx testing has the capabilities to individualise primary care and build a safer drug prescription model than the current "one-size-fits-all" approach. In particular, the use of PGx testing in psychiatry has shown promising evidence in improving drug efficacy as well as reducing toxicity and adverse drug reactions. Despite randomised controlled trials demonstrating an evidence base for its use, there are still numerous barriers impeding its implementation. This review paper will discuss the management of mental health conditions with PGx-guided treatment with a strong focus on youth mental illness. PGx testing in clinical practice, the concerns for its implementation in youth psychiatry, and some of the barriers inhibiting its integration in clinical healthcare will also be discussed. Overall, this paper provides a comprehensive review of the current state of knowledge and application for PGx in psychiatry and summarises the capabilities of genetic information to personalising medicine for the treatment of mental ill-health in youth.

Multiple routes to enhanced memory for emotionally relevant events

Events associated with aversive or rewarding outcomes are prioritized in memory. This memory boost is commonly attributed to the elicited affective response, closely linked to noradrenergic and dopaminergic modulation of hippocampal plasticity. Herein we review and compare this 'affect' mechanism to an additional, recently discovered, 'prediction' mechanism whereby memories are strengthened by the extent to which outcomes deviate from expectations, that is, by prediction errors (PEs). The mnemonic impact of PEs is separate from the affective outcome itself and has a distinct neural signature. While both routes enhance memory, these mechanisms are linked to different - and sometimes opposing - predictions for memory integration. We discuss new findings that highlight mechanisms by which emotional events strengthen, integrate, and segment memory.

Neuroinflammation in the Amygdala Is Associated With Recent Depressive Symptoms

BACKGROUND

Converging evidence suggests that elevated inflammation may contribute to depression. Yet, the link between peripheral inflammation and neuroinflammation in depression is unclear. Here, using data from the UK Biobank, we estimated associations among depression, C-reactive protein (CRP) as a measure of peripheral inflammation, and neuroinflammation as indexed by diffusion basis spectral imaging-based restricted fraction (DBSI-RF).

METHODS

DBSI-RF was derived from diffusion-weighted imaging data (N = 11,512) for whole-brain gray matter (global-RF), and regions of interest in the bilateral amygdala (amygdala-RF) and hippocampus (hippocampus-RF), and CRP was estimated from blood (serum) samples. Self-reported recent depression symptoms were measured using a 4-item assessment. Linear regressions were used to estimate associations between CRP and DBSI-RFs with depression while adjusting for the following covariates: age, sex, body mass index, smoking, drinking, and medical conditions.

RESULTS

Elevated CRP was associated with higher depression symptoms (β = 0.04, false discovery rate-corrected p < .005) and reduced global-RF (β = -0.03, false discovery rate-corrected p < .001). Higher amygdala-RF was associated with elevated depression-an effect resilient to added covariates and CRP (β = 0.02, false discovery rate-corrected p < .05). Interestingly, this association was stronger in individuals with a lifetime history of depression (β = 0.07, p < .005) than in those without (β = 0.03, p < .05). Associations between global-RF or hippocampus-RF with depression were not significant, and no DBSI-RF indices indirectly linked CRP with depression (i.e., mediation effect).

CONCLUSIONS

Peripheral inflammation and DBSI-RF neuroinflammation in the amygdala are independently associated with depression, consistent with animal studies suggesting distinct pathways of peripheral inflammation and neuroinflammation in the pathophysiology of depression and with investigations highlighting the role of the amygdala in stress-induced inflammation and depression.

Collective events and individual affect shape autobiographical memory

How do collective events shape how we remember our lives? We leveraged advances in natural language processing as well as a rich, longitudinal assessment of 1,000 Americans throughout 2020 to examine how memory is influenced by two prominent factors: surprise and emotion. Autobiographical memory for 2020 displayed a unique signature: There was a substantial bump in March, aligning with pandemic onset and lockdowns, consistent across three memory collections 1 y apart. We further investigated how emotion, using both immediate and retrieved measures, predicted the amount and content of autobiographical memory: Negative affect increased recall across all measures, whereas its more clinical indices, depression and posttraumatic stress disorder, selectively increased nonepisodic recall. Finally, in a separate cohort, we found pandemic news to be better remembered, surprising, and negative, while lockdowns compressed remembered time. Our work connects laboratory findings to the real world and delineates the effects of acute versus clinical signatures of negative emotion on memory.

A cross-lagged prospective network analysis of depression and anxiety and cognitive functioning components in midlife community adult women

BACKGROUND

Scar theory proposes that heightened depression and anxiety precede and predict worse cognitive functioning outcomes, whereas the vulnerability theory posits the opposite pathway. However, most investigations on this topic have been cross-sectional, precluding causal inferences. Thus, we used cross-lagged prospective network analyses to facilitate causal inferences in understanding the relations between psychopathology and cognitive functioning components.

METHODS

Racially-diverse midlife women (n = 1816) participated in the Study of Women's Health Across the Nation at two time-points, spanning one year apart. Five psychopathology (anxiety severity, depressed mood, somatic symptoms, positive affect, interpersonal problems) and four cognitive functioning nodes (working memory (WM), processing speed (PS), facial recognition (FCR), and verbal memory (VRM)) were assessed. All analyses adjusted for age, menopausal status, estradiol, and follicle-stimulating hormones.

RESULTS

Contemporaneous networks yielded notable inverse between-node relations (edges) between interpersonal problems and reduced FCR and PS, and between depressed mood and lower FCR, VRM, or PS. Nodes that had the highest likelihood to bridge other constructs were positive affect, anxiety severity, WM, and VRM. Temporal networks produced edges consistent with the scar (v. vulnerability) hypotheses. Higher somatic symptoms were related to reduced PS and WM, and greater depressed mood was correlated with lower future PS and WM. Also, higher anxiety severity coincided with decreased future PS and WM. Greater positive affect was associated with stronger future PS, FCR, and WM. Also, positive affect had the strongest relations with other nodes.

CONCLUSIONS

Findings suggest the importance of targeting symptoms and cognitive functioning simultaneously.

Exploring the role of neuronal-enriched extracellular vesicle miR-93 and interoception in major depressive disorder

Major depressive disorder (MDD) is associated with interoceptive processing dysfunctions, but the molecular mechanisms underlying this dysfunction are poorly understood. This study combined brain Neuronal-Enriched Extracellular Vesicle (NEEV) technology and serum markers of inflammation and metabolism with Functional Magnetic Resonance Imaging (fMRI) to identify the contribution of gene regulatory pathways, in particular micro-RNA (miR) 93, to interoceptive dysfunction in MDD. Individuals with MDD (n = 44) and healthy comparisons (HC; n = 35) provided blood samples and completed an interoceptive attention task during fMRI. EVs were separated from plasma using a precipitation method. NEEVs were enriched by magnetic streptavidin bead immunocapture utilizing a neural adhesion marker (CD171) biotinylated antibody. NEEV specificities were confirmed by ow cytometry, western blot, particle size analyzer, and transmission electron microscopy. NEEV small RNAs were purified and sequenced. Results showed that: (1) MDD exhibited lower NEEV miR-93 expression than HC; (2) within MDD but not HC, those individuals with the lowest NEEV miR-93 expression had the highest serum concentrations of interleukin (IL)-1 receptor antagonist, IL-6, tumor necrosis factor, and leptin; and (3) within HC but not MDD, those participants with the highest miR-93 expression showed the strongest bilateral dorsal mid-insula activation. Since miR-93 is regulated by stress and affects epigenetic modulation by chromatin reorganization, these results suggest that healthy individuals but not MDD participants show an adaptive epigenetic regulation of insular function during interoceptive processing. Future investigations will need to delineate how specific internal and external environmental conditions contribute to miR-93 expression in MDD and what molecular mechanisms alter brain responsivity to body-relevant signals.

Xanthine-induced deficits in hippocampal behavior and abnormal expression of hemoglobin genes

The prevalence of mental disorders such as depression and anxiety is high and often comorbid with other diseases. Chronic stress is a common risk factor for these disorders, but the mechanisms behind their development are not yet fully understood. Metabolomics has revealed a close association between purine and pyrimidine metabolism and depression and anxiety, with increased levels of serum xanthine observed in both humans and mice. Xanthine is known as purine metabolism, and this compound shows several biological activities, but the impact of xanthine on our brain function is still unclear. The hippocampus, which plays a crucial role in memory and learning, is also implicated in the pathophysiology of depression and anxiety. Here, we investigated the effects of xanthine intraperitoneal administration on spatial memory and anxiety-like behavior in mice. The findings indicated that xanthine administration induced a deficit of hippocampus-dependent spatial memory and a tendency to anxiety-like behavior in mice. RNA-seq analysis showed that xanthine administration upregulated hemoglobin (Hb) genes involved in oxygen transport in the hippocampus. The upregulated Hb genes occurred in the neuronal cells, and in vitro experiments revealed that both Hba-a1 derived from mice and HBA2 derived from humans were upregulated by xanthine treatment. These observations suggest that the xanthine-induced Hb in the hippocampus could be related to spatial memory deficit and anxiety. This study sheds light on the direct effects of xanthine on the brain and its potential role in the development of depression and anxiety symptoms caused by chronic stress.

Memory impairments in rodent depression models: A link with depression theories

More than 80% of depressed patients struggle with learning new tasks, remembering positive events, or concentrating on a single topic. These neurocognitive deficits accompanying depression may be linked to functional and structural changes in the prefrontal cortex and hippocampus. However, their mechanisms are not yet completely understood. We conducted a narrative review of articles regarding animal studies to assess the state of knowledge. First, we argue the contribution of changes in neurotransmitters and hormone levels in the pathomechanism of cognitive dysfunction in animal depression models. Then, we used numerous neuroinflammation studies to explore its possible implication in cognitive decline. Encouragingly, we also observed a positive correlation between increased oxidative stress and a depressive-like state with concomitant memory deficits. Finally, we discuss the undeniable role of neurotrophin deficits in developing cognitive decline in animal models of depression. This review reveals the complexity of depression-related memory impairments and highlights the potential clinical importance of gathered findings for developing more reliable animal models and designing novel antidepressants with procognitive properties.

The Acute Effects of Psychoactive Drugs on Emotional Episodic Memory Encoding, Consolidation, and Retrieval

Psychoactive drugs modulate learning and emotional processes in ways that could impact their recreational and medical use. Recent work has revealed how drugs impact different stages of processing emotional episodic memories, specifically encoding (forming memories), consolidation (stabilizing memories), and retrieval (accessing memories). Drugs administered before encoding may preferentially impair (e.g., GABA_A sedatives including alcohol and benzodiazepines, Δ⁹-tetrahydrocannabinol or THC, ketamine), enhance (e.g., dextroamphetamine and dextromethamphetamine), or both impair and enhance (i.e., ±3,4-methylenedioxymethylamphetamine or MDMA) emotionally negative and positive compared to neutral memories. GABA_A sedatives administered immediately post-encoding (during consolidation) can preferentially enhance emotional memories, though this selectivity may decline or even reverse (i.e., preferential enhancement of neutral memories) as the delay between encoding and retrieval increases. Finally, retrieving memories under the effects of THC, dextroamphetamine, MDMA, and perhaps GABA_A sedatives distorts memory, with potentially greater selectively for emotional (especially positive) memories. We review these effects, propose neural mechanisms, discuss methodological considerations for future work, and speculate how drug effects on emotional episodic memory may contribute to drug use and abuse.

Circadian regulation of hippocampal function is disrupted with corticosteroid treatment

Disrupted circadian activity is associated with many neuropsychiatric disorders. A major coordinator of circadian biological systems is adrenal glucocorticoid secretion which exhibits a pronounced preawakening peak that regulates metabolic, immune, and cardiovascular processes, as well as mood and cognitive function. Loss of this circadian rhythm during corticosteroid therapy is often associated with memory impairment. Surprisingly, the mechanisms that underlie this deficit are not understood. In this study, in rats, we report that circadian regulation of the hippocampal transcriptome integrates crucial functional networks that link corticosteroid-inducible gene regulation to synaptic plasticity processes via an intrahippocampal circadian transcriptional clock. Further, these circadian hippocampal functions were significantly impacted by corticosteroid treatment delivered in a 5-d oral dosing treatment protocol. Rhythmic expression of the hippocampal transcriptome, as well as the circadian regulation of synaptic plasticity, was misaligned with the natural light/dark circadian-entraining cues, resulting in memory impairment in hippocampal-dependent behavior. These findings provide mechanistic insights into how the transcriptional clock machinery within the hippocampus is influenced by corticosteroid exposure, leading to adverse effects on critical hippocampal functions, as well as identifying a molecular basis for memory deficits in patients treated with long-acting synthetic corticosteroids.

Dorsolateral prefrontal activation in depressed young adults with and without suicidal ideation during an emotional autobiographical memory task: A fNIRS study

OBJECTIVE

Previous studies have proved that there is a strong association between dorsolateral prefrontal cortex and mood symptoms. This study aimed at using functional near-infrared spectroscopy technology to invest brain activity in dlPFC of depressed individuals with and without suicidal ideation during emotional autobiographical memory test, and to understand their differences in brain cognitive mechanisms. It is helpful to improve our ability to predict and subsequently to prevent suicide.

METHODS

85 young adults participated in the study by a simple random sampling method, with health control (34participants), depression with suicidal ideation (17participants), and depression without suicidal ideation (34participants). The average oxyhemoglobin in dlPFC of subjects during EAMT was collected by a 53-channel fNIRS imaging device.

RESULTS

A marginal significant difference was found between three groups in left dlPFC and right dlPFC. Post hoc analysis revealed that: (1) under negative emotion, depression without suicidal ideation group had higher activation than healthy control group in left dlPFC. (2) under positive emotion, depression with suicidal ideation group had lower activation than healthy control in right dlPFC.

CONCLUSIONS

Results indicated that the depressed individuals with suicidal ideation had some deficits in executive function in right dlPFC, while the depressed adults without suicidal ideation may have mechanism of resource compensatory recruitment in left dlPFC and the dlPFC abnormality involved in the pathophysiology, may localize within left hemisphere. The depressed individuals with and without suicidal ideation had the different mechanisms in dlPFC and fNIRS can be a neuroimaging biomarker characterizing or predicting suicidality in depressed individuals.

Potential Anti-Amnesic Activity of a Novel Multimodal Derivative of Salicylamide, JJGW08, in Mice

Memory impairments constitute a significant problem worldwide, and the COVID-19 pandemic dramatically increased the prevalence of cognitive deficits. Patients with cognitive deficits, specifically memory disturbances, have underlying comorbid conditions such as schizophrenia, anxiety, or depression. Moreover, the available treatment options have unsatisfactory effectiveness. Therefore, there is a need to search for novel procognitive and anti-amnesic drugs with additional pharmacological activity. One of the important therapeutic targets involved in the modulation of learning and memory processes are serotonin receptors, including 5-HT1A, 5-HT6, and 5-HT7, which also play a role in the pathophysiology of depression. Therefore, this study aimed to assess the anti-amnesic and antidepressant-like potential of JJGW08, a novel arylpiperazine alkyl derivative of salicylamide with strong antagonistic properties at 5-HT1A and D2 receptors and weak at 5-HT2A and 5-HT7 receptors in rodents. First, we investigated the compound’s affinity for 5-HT6 receptors using the radioligand assays. Next, we assessed the influence of the compound on long-term emotional and recognition memory. Further, we evaluated whether the compound could protect against MK-801-induced cognitive impairments. Finally, we determined the potential antidepressant-like activity of the tested compound. We found that JJGW08 possessed no affinity for 5-HT6 receptors. Furthermore, JJGW08 protected mice against MK-801-induced recognition and emotional memory deficits but showed no antidepressant-like effects in rodents. Therefore, our preliminary study may suggest that blocking serotonin receptors, especially 5-HT1A and 5-HT7, might be beneficial in treating cognitive impairments, but it requires further investigation.

The Antidepressant-like Activity and Cognitive Enhancing Effects of the Combined Administration of (R)-Ketamine and LY341495 in the CUMS Model of Depression in Mice Are Related to the Modulation of Excitatory Synaptic Transmission and LTP in the PFC

(S)-Ketamine is the first rapid-acting antidepressant drug (RAAD) introduced for the treatment of depression. However, research is still being carried out on the search for further RAADs that will be not only effective but also safe to use. Recent data have indicated that the combined administration of (R)-ketamine and the mGlu2/3 receptor antagonist LY341495 (mixRL) induces rapid and sustained effects in the chronic unpredictable mild stress (CUMS) model of depression in mice, and the use of this drug combination is associated with a low risk of undesirable effects. Considering the possible influence of stress on cortical plasticity and, on the other hand, the role of this plasticity in the mechanism of action of ketamine, we decided to investigate whether mixed RL affects synaptic plasticity in the prefrontal cortex (PFC) in the CUMS model of depression using electrophysiological techniques and explore whether these effects are related to memory impairments. Using behavioral methods, we found that a single administration of mixRL reversed CUMS-induced PFC-dependent memory deficits and alleviated depression-like effects induced by CUMS. In turn, electrophysiological experiments indicated that the amplitude of field potentials as well as paired-pulse responses in CUMS mice were increased, and mixRL was found to reverse these effects. Additionally, the magnitude of long-term potentiation (LTP) was reduced in CUMS mice, and mixRL was shown to restore this parameter. In summary, mixRL appeared to exert its antidepressant effects and cognitive enhancing effects in a mouse model of depression, at least in part, by mechanisms involving modulation of glutamatergic transmission and LTP in the PFC.

Memory and processing speed impairments in first-episode drug-naïve patients with major depressive disorder

BACKGROUND

Cognitive impairment, an intrinsic feature of major depressive disorder (MDD), affects daily and social functioning in depression patients. However, the cognitive impairment profile in MDD remains ambiguous because of the high heterogeneity of previous studies.

METHODS

Four cognitive domains, including memory, processing speed, executive function (EF), and attention, were assessed in 184 first-episode drug-naïve (FEDN) MDD patients and matched 71 healthy controls (HCs). The effects of demographic and depressive factors on cognitive performance were analyzed using various statistical methods, including multi-factor analysis of variance, Mann-Whitney U test, and Spearman's rank correlation. In addition, the impact of depression severity on cognitive function was further assessed using subgroup analyses and partial correlation analyses.

RESULTS

Age and education significantly impacted most cognitive performances, and depression severity appeared to influence processing speed. Moreover, cognitive scores in memory and processing speed, rather than in EF and attention, were significantly different between FEDN MDD patients and HCs after controlling for sex, age, educational attainment, household income, and body mass index.

LIMITATIONS

The number of HCs was relatively small, which may have slightly reduced the study's statistical power.

CONCLUSIONS

Age and educational attainment have confirmative confounding effects greater than those of depression in most cognitive functions. More importantly, memory and processing speed were impaired in MDD after strictly controlling for confounders. These findings provide new information for understanding the pattern of cognitive impairment and offer clues for further exploring the pathogenesis of cognitive abnormalities in MDD.

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.