The Association Between Adverse Childhood Experiences and Inflammation in Patients with Major Depressive Disorder: A Systematic Review

Multimodal brain-derived subtypes of Major depressive disorder differentiate patients for anergic symptoms, immune-inflammatory markers, history of childhood trauma and treatment-resistance

An estimated 30 % of Major Depressive Disorder (MDD) patients exhibit resistance to conventional antidepressant treatments. Identifying reliable biomarkers of treatment-resistant depression (TRD) represents a major goal of precision psychiatry, which is hampered by the clinical and biological heterogeneity. To uncover biologically-driven subtypes of MDD, we applied an unsupervised data-driven framework to stratify 102 MDD patients on their neuroimaging signature, including extracted measures of cortical thickness, grey matter volumes, and white matter fractional anisotropy. Our novel analytical pipeline integrated different machine learning algorithms to harmonize data, perform data dimensionality reduction, and provide a stability-based relative clustering validation. The obtained clusters were characterized for immune-inflammatory peripheral biomarkers, TRD, history of childhood trauma and depressive symptoms. Our results indicated two different clusters of patients, differentiable with 67 % of accuracy: one cluster (n = 59) was associated with a higher proportion of TRD, and higher scores of energy-related depressive symptoms, history of childhood abuse and emotional neglect; this cluster showed a widespread reduction in cortical thickness (d = 0.43-1.80) and volumes (d = 0.45-1.05), along with fractional anisotropy in the fronto-occipital fasciculus, stria terminalis, and corpus callosum (d = 0.46-0.52); the second cluster (n = 43) was associated with cognitive and affective depressive symptoms, thicker cortices and wider volumes. Multivariate analyses revealed distinct brain-inflammation relationships between the two clusters, with increase in pro-inflammatory markers being associated with decreased cortical thickness and volumes. Our stratification of MDD patients based on structural neuroimaging identified clinically-relevant subgroups of MDD with specific symptomatic and immune-inflammatory profiles, which can contribute to the development of tailored personalized interventions for MDD.

Association between adverse childhood experiences and type 2 diabetes mellitus in later life: A case-control study

Adverse childhood experiences (ACEs) are potentially traumatic events that occur before 18 years of age. Studies emphasize the importance of childhood adversity as a risk factor for developing non-communicable diseases, including type-2 diabetes mellitus (T2DM) in adulthood. This case-control study involved 137 patients with T2DM and 134 non-diabetic adults of both genders (mean age 46.9 and 45.7 years, respectively). In addition to collecting socio-demographic, behavioral, and anthropological data, a 10-item ACE scale was utilized to gather information regarding childhood adversities, while perceived stress was assessed using the perceived stress scale-4. Fasting and 2-hour post glucose load blood sugar levels, HbA1c, and fasting lipid profiles were measured. Both univariable and multivariable binary logistic regression analyses were performed to investigate whether ACE is a potential risk factor for T2DM, with a significance level of 0.05. Around two-thirds of T2DM patients reported having ACE scores of 4 or higher, with the mean ACE score significantly higher in the case group than in the control group (3.96 vs. 3.34; p<0.0001). The logistic regression analysis found that T2DM was linked to female gender, hypertension, dyslipidemia, family history of DM, higher perceived stress, and a higher ACE score of 4 and above. After adjusting for confounding factors, individuals with an ACE score of 4 or higher had a significantly greater risk of developing T2DM (OR: 2.24; 95% CI 1.238-4.061). The study revealed a significant association between higher ACE scores and an increased risk of developing T2DM. As a recommendation, further investigation into the epigenetic mechanisms underlying this relationship is warranted.

Social determinants of inflammatory markers linking depression and type 2 diabetes among women: A scoping review

OBJECTIVE

Inflammation is implicated in the pathophysiology of depression and type 2 diabetes (T2D) and is linked to social determinants of health (SDoH) associated with socioeconomic disadvantage. The objective of this review is to identify and map the range of SDoHs associated with inflammation in depression, T2D, or their co-occurrence among women.

METHODS

PubMed, CINAHL, PsychINFO, and Web of Science were searched March-July 2023 to identify studies where 1) an SDoH was a predictor or independent variable, 2) depression or T2D was a clinical focus, 3) inflammatory markers were collected, and 4) analysis was specific to women. We used the National Institute on Minority Health and Health Disparities research framework to guide searching SDoHs, organize findings, and identify gaps.

RESULTS

Of the 1135 studies retrieved, 46 met criteria. Within the reviewed studies, the most used inflammatory measures were C-reactive protein, interleukin-6, and tumor necrosis factor-α, and the most studied SDoHs were early life stress and socioeconomic status. Individual and interpersonal-level variables comprised the bulk of SDoHs in the included studies, while few to no studies examined built environment (n = 6) or health system level (n = 0) factors. Disadvantageous SDoHs were associated with higher levels of inflammation across the included studies.

CONCLUSION

The scope and intersection of depression and T2D represent a syndemic that contributes to and results from socioeconomic inequities and disproportionately affects women. Simultaneous inclusion of social and inflammatory measures, particularly understudied SDoHs, is needed to clarify potent targets aimed at advancing health and equity.

Type of cycle, temperament and childhood trauma are associated with lithium response in patients with bipolar disorders

BACKGROUND

Lithium stands as the gold standard in treating bipolar disorders (BD). Despite numerous clinical factors being associated with a favorable response to lithium, comprehensive studies examining the collective influence of clinical variables alongside psychopathological dimensions are lacking. Our study aims to enhance comprehension of lithium response in individuals with BD by integrating clinical variables with psychopathological traits and early adverse events.

METHODS

We assessed 201 patients with BD for clinical characteristics, childhood trauma, temperament traits, impulsivity, and aggression. Lithium response was evaluated using the gold standard Alda scale, and predictors of lithium response were estimated through a multivariate model.

RESULTS

On the total sample, 61 (30.3%) patients were lithium responders according to the Alda scale. Comparatively, lithium responders, in contrast to non-responders, demonstrated a higher prevalence of the mania-depression-interval (MDI) cycle, a more frequent diagnosis of BD type I, and reported an earlier age of onset. They also exhibited less lifetime substance abuse, emotional, physical, and sexual abuse, while scoring higher on hyperthymic and irritable temperament scales. In multivariate analyses, only the MDI cycle (OR,3.47; 95%CI,1.61-7.50) hyperthymic (OR,1.20; 95%CI,1.02-1.41) and irritable temperament (OR,1.28; 95%CI,1.08-1.52) persisted as significant predictors of a positive response to lithium treatment, while emotional (OR,0.87; 95%CI,0.76-0.98) and physical abuse (OR,0.83; 95%CI,0.70-0.98) were predictors of non-response.

CONCLUSIONS

In evaluating lithium response in BD, our study highlights the importance of considering clinical variables alongside temperament and childhood adversities. The assessment of hyperthymic and irritable temperament, emotional and physical abuse together with the type of cycle is of particular importance. Furthermore, our findings underscore the significance of systematically assessing the type of cycle in patients with BD through the use of life charts.

Adverse childhood experience and depression: the role of gut microbiota

Depression is the most common psychiatric disorder that burdens modern society heavily. Numerous studies have shown that adverse childhood experiences can increase susceptibility to depression, and depression with adverse childhood experiences has specific clinical-biological features. However, the specific neurobiological mechanisms are not yet precise. Recent studies suggest that the gut microbiota can influence brain function and behavior associated with depression through the "microbe-gut-brain axis" and that the composition and function of the gut microbiota are influenced by early stress. These studies offer a possibility that gut microbiota mediates the relationship between adverse childhood experiences and depression. However, few studies directly link adverse childhood experiences, gut microbiota, and depression. This article reviews recent studies on the relationship among adverse childhood experiences, gut microbiota, and depression, intending to provide insights for new research.

Struggling Can Also Show on the Inside: Current Knowledge of the Impact of Childhood Maltreatment on Biomarkers in Mood Disorders

The link between childhood maltreatment and mood disorders is complex and involves multiple bio-psycho-social factors that affect multiple molecular pathways. The present narrative review aims to clarify the current understanding of the impact of childhood maltreatment on biomarkers in patients with mood disorders and their first-degree relatives. Neurotransmitters, such as serotonin, dopamine, norepinephrine, and hormones (eg the stress hormone cortisol), play a crucial role in regulating mood and emotion. Childhood maltreatment can alter and affect the levels and functioning of these neurotransmitters in the brain; further, childhood maltreatment can lead to structural and connectivity changes in the brain, hence contributing to the development of mood disorders and moderating illness presentation and modifying response to treatments. Childhood maltreatment information, therefore, appears mandatory in treatment planning and is a critical factor in therapeutic algorithms. Further research is needed to fully understand these pathways and develop new treatment modalities for individuals with mood disorders who have experienced childhood maltreatment and effective preventive interventions for individuals at risk of developing mood disorders.

Genetics, epigenetics, and neurobiology of childhood-onset depression: an umbrella review

Depression is a serious and persistent psychiatric disorder that commonly first manifests during childhood. Depression that starts in childhood is increasing in frequency, likely due both to evolutionary trends and to increased recognition of the disorder. In this umbrella review, we systematically searched the extant literature for genetic, epigenetic, and neurobiological factors that contribute to a childhood onset of depression. We searched PubMed, EMBASE, OVID/PsychInfo, and Google Scholar with the following inclusion criteria: (1) systematic review or meta-analysis from a peer-reviewed journal; (2) inclusion of a measure assessing early age of onset of depression; and (3) assessment of neurobiological, genetic, environmental, and epigenetic predictors of early onset depression. Findings from 89 systematic reviews of moderate to high quality suggest that childhood-onset depressive disorders have neurobiological, genetic, environmental, and epigenetic roots consistent with a diathesis-stress theory of depression. This review identified key putative markers that may be targeted for personalized clinical decision-making and provide important insights concerning candidate mechanisms that might underpin the early onset of depression.

A developmental framework for understanding the influence of sex and gender on health: Pediatric pain as an exemplar

Sex differences are a robust finding in many areas of adult health, including cardiovascular disease, psychiatric disorders, and chronic pain. However, many sex differences are not consistently observed until after the onset of puberty. This has led to the hypothesis that hormones are primary contributors to sex differences in health outcomes, largely ignoring the relative contributions of early developmental influences, emerging psychosocial factors, gender, and the interaction between these variables. In this paper, we argue that a comprehensive understanding of sex and gender contributions to health outcomes should start as early as conception and take an iterative biopsychosocial-developmental perspective that considers intersecting social positions. We present a conceptual framework, informed by a review of the literature in basic, clinical, and social science that captures how critical developmental stages for both sex and gender can affect children's health and longer-term outcomes. The literature on pediatric chronic pain is used as a worked example of how the framework can be applied to understanding different chronic conditions.

Correlation Between Systemic Immune-Inflammation Index and Suicide Attempts in Children and Adolescents with First-Episode, Drug-Naïve Major Depressive Disorder During the COVID-19 Pandemic

Objective

This study aims to investigate the association between the systemic immune-inflammatory index (SII) and suicide attempt (SA) in children and adolescents with first-episode, drug-naïve Major Depressive Disorder (MDD) during the COVID-19 pandemic.

Methods

A retrospective study was conducted on 263 MDD patients hospitalized at the Third Hospital of Fuyang City between 2020 and 2022. Patients were categorized into two groups based on the presence of previous SA. The study compared the differences in SII and clinical characteristics between the two groups and used the receiver operating characteristic (ROC) curve to determine the optimal critical value of SII and the area under the curve. Binary logistic regression was used to analyze the independent risk factors for SA.

Results

Compared with the patients without SA history, the patients with a personal history of SA had a higher mean HDRS scores (Z=-2.369, p=0.018), higher mean neutrophil count (Z=-2.870, p=0.004), higher mean platelet count (Z=-2.155, p=0.031), and higher mean SII (Z=-3.170, p=0.002). The optimal critical SII determined by the ROC curve was 548.15 (sensitivity = 63.2%, specificity = 83.1%), and the area under the curve was 0.661. After adjusting for gender, age, BMI, illness duration and HDRS score, the risk of total SA in patients with high SII was 8.296 times higher than in those with low SII (OR = 8.296, 95% CI: 3.803-18.095, P < 0.001), The risk of recent SA was 13.922 times higher in patients with high SII than in those with low SII (OR = 13.922, 95% CI: 5.587-34.693, p < 0.001). However, high SII was not a risk factor for past SA (OR = 0.547, 95% CI: 0.062-4.842, P=0.587).

Conclusion

SII may be an inexpensive, easily accessible strategy that can assist in determining suicide risk in adolescents with MDD.

The effect of adverse childhood experiences on chronic pain and major depression in adulthood: a systematic review and meta-analysis

BACKGROUND

Adverse childhood experiences have been linked to increased multimorbidity, with physical and mental health consequences throughout life. Chronic pain is often associated with mood disorders, such as major depressive disorder (MDD); both have been linked to adverse childhood experiences. It is unclear how the effect of adverse childhood experiences on neural processing impacts on vulnerability to chronic pain, MDD, or both, and whether there are shared mechanisms. We aimed to assess evidence for central neural changes associated with adverse childhood experiences in subjects with chronic pain, MDD, or both using systematic review and meta-analysis.

METHODS

Electronic databases were systematically searched for neuroimaging studies of adverse childhood experiences, with chronic pain, MDD, or both. Two independent reviewers screened title, abstracts, and full text, and assessed quality. After extraction of neuroimaging data, activation likelihood estimate meta-analysis was performed to identify significant brain regions associated with these comorbidities.

RESULTS

Forty-nine of 2414 studies were eligible, of which 43 investigated adverse childhood experiences and MDD and six investigated adverse childhood experiences and chronic pain. None investigated adverse childhood experiences, chronic pain, and MDD together. Functional and structural brain abnormalities were identified in the superior frontal, lingual gyrus, hippocampus, insula, putamen, superior temporal, inferior temporal gyrus, and anterior cerebellum in patients with MDD exposed to adverse childhood experiences. In addition, brain function abnormalities were identified for patients with MDD or chronic pain and exposure to adverse childhood experiences in the cingulate gyrus, inferior parietal lobule, and precuneus in task-based functional MRI studies.

CONCLUSIONS

We found that adverse childhood experiences exposure can result in different functional and structural brain alterations in adults with MDD or chronic pain compared with those without adverse childhood experiences.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO CRD42021233989.

Serum claudin-5 levels among patients with unipolar and bipolar depression in relation to the pro-inflammatory cytokine tumor necrosis factor-alpha levels

Accumulating evidence indicates that inflammation and neurovascular unit (NVU) dysfunction contribute to depression via disrupted blood-brain barrier (BBB) integrity. Claudin-5, an endothelial tight-junction protein expressed in the NVU and contributing to BBB integrity, has been implicated in psychiatric disorders, including major depressive disorder (MDD) and schizophrenia. In an animal model of depressive-like behavior, the pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-α) was found to affect BBB permeability and claudin-5 expression of NVU endothelial cells. To the best of the authors' knowledge, this study is the first to assess the relationship between serum claudin-5 and TNF-α levels, during major depressive episodes (MDEs). Serum levels of claudin-5 and TNF-α of 40 patients diagnosed with current MDE [19 with MDD and 21 with bipolar disorder (BD)] and 28 matched healthy controls (HCs) were analyzed. Claudin-5 and TNF-α serum levels in the MDE group were significantly higher than in the HC one. Discrete analysis according to MDE type indicated significantly increased claudin-5 serum levels in BD but not in MDD patients, compared to HCs, even after controlling for confounders. In the MDE group, a significant positive correlation was found between claudin-5 and TNF-α serum levels. In complementary analysis, serum levels of the pro-inflammatory cytokine interleukin-6 were significantly higher among MDE patients compared to HCs, however, no significant correlation was found with claudin-5 levels. In conclusion, as indicated by preclinical studies, our clinical study suggests a possible specific interaction between the NVU/BBB marker claudin-5 and the inflammatory marker TNF-α in the pathogenesis of depression.

White matter integrity and pro-inflammatory cytokines as predictors of antidepressant response in MDD

Major depressive disorder (MDD) is a multifactorial, serious and heterogeneous mental disorder that can lead to chronic recurrent symptoms, treatment resistance and suicidal behavior. MDD often involves immune dysregulation with high peripheral levels of inflammatory cytokines that might have an influence on the clinical course and treatment response. Moreover, patients with MDD show brain volume changes as well as white matter (WM) alterations that are already existing in the early stage of illness. Mounting evidence suggests that both neuroimaging markers, such as WM integrity and blood markers, such as inflammatory cytokines might serve as predictors of treatment response in MDD. However, the relationship between peripheral inflammation, WM structure and antidepressant response is not yet clearly understood. The aim of the present review is to elucidate the association between inflammation and WM integrity and its impact on the pathophysiology and progression of MDD as well as the role of possible novel biomarkers of treatment response to improve MDD prevention and treatment strategies.

Gender- and age-specific associations of childhood maltreatment with peripheral serum inflammatory cytokines in middle school students

Background

The impact of childhood maltreatment on multiple inflammatory cytokines among middle school students remains to be elucidated. This study aimed to examine the associations of different types of childhood maltreatment with peripheral serum inflammatory cytokines (interleukin-10, interleukin-1β, interleukin-6, interleukin-8, and tumor necrosis factor-α) in middle school students, and to explore the differences in these associations between boys and girls and between late (≥15 and<20 years) and early (≥11 and <15 years) adolescence.

Methods

A total of 1122 students were recruited from a boarding middle school. Each participant was asked to respond to a detailed questionnaire on childhood maltreatment, from whom one blood sample was drawn via venous blood.

Results

In the overall sample there was no association between childhood maltreatment and peripheral serum inflammatory cytokines; (2) emotional abuse was significantly correlated with IL-1β only in girls (B = -0.16; 95% CI, -0.28~-0.03; p = 0.06); (3) in late adolescence, emotional abuse, emotional neglect, and childhood maltreatment had marked link with IL-8 (B = 0.39; 95%CI, 0.16~0.63; p = 0.01; B =0.20; 95% CI, 0.04~0.37; p = 0.08; B = 0.50; 95% CI, 0.18~0.82; p = 0.01, respectively).

Conclusion

These findings also strengthened an inference regarding the effects of childhood maltreatment on inflammation of students in late adolescence.

Increased immunological markers in female adolescents with non-suicidal self-injury

BACKGROUND

Nonsuicidal self-injury (NSSI) is a prevalent health problem among adolescents and commonly associated with psychological stressors such as childhood maltreatment and comorbid psychiatric disorders (e.g., depression). There is evidence that alterations of immunological markers may occur in the context of both environmental stress and psychopathological development.

METHOD

Here, we investigated differences in plasma/serum leukocytes, cortisol, c-reactive protein and interleukin-6 in a large sample of female adolescents with NSSI (n = 155) and healthy controls (HC, n = 42). Further, we assessed correlations between inflammatory markers, depression severity and the severity of childhood maltreatment.

RESULTS

The absolute number of leukocytes and the leukocyte/cortisol ratio (adjusted for body mass index and smoking) were significantly higher in NSSI as compared to HC, whereas interleukin-6 and CRP levels did not differ significantly between groups. Childhood maltreatment scores were significantly correlated with the leukocyte/cortisol ratio and depression severity was significantly correlated with both, absolute leukocyte numbers and the leukocyte/cortisol ratio.

CONCLUSIONS

Our results suggest that an immune activation can be detected in female adolescents with NSSI. Depression and childhood maltreatment, which are commonly reported in NSSI, may potentially underlie immune activation and partially explain group differences.

Plasma complement C3 and C3a are increased in major depressive disorder independent of childhood trauma

BACKGROUND

Dysregulated complement system is linked to pathophysiology of major depressive disorder (MDD). Childhood trauma has been associated with an increased incidence of adult depression via a putative mechanism of immune activation. This study aimed to measure and compare peripheral levels of complement C3, C3a, C1q and C-reactive protein (CRP) in MDD patients and healthy controls and explore the relationship between these molecule levels and childhood trauma history in the participants.

METHODS

The participants were 49 medication-free MDD patients and 45 healthy controls. All participants were asked to finish the Childhood Trauma Questionnaire, followed by blood sampling for measurement of plasma complement C3, C3a, C1q and CRP by means of enzyme-linked immunosorbent assay.

RESULTS

Peripheral plasma concentration of C3 and C3a in medication-free MDD group was significantly higher than that in the healthy controls; whereas the concentration of plasma C1q and CRP in depressed patients was comparable to that in healthy controls. All these inflammatory factors were not associated to childhood trauma experience in patients with MDD.

CONCLUSION

Our data suggest that complement C3 and C3a may be implicated in the pathophysiology of MDD, although traumatic childhood experiences were not associated with the circulating levels of complement C3, C3a, C1q and CRP.

Childhood trauma and LPS-stimulated inflammation in adulthood: Results from the Netherlands Study of Depression and Anxiety

BACKGROUND

Childhood trauma (CT) is robustly associated with psychiatric disorders including major depressive and anxiety disorders across the life span. The innate immune system may play a role in the relation between CT and stress-related psychopathology. However, whether CT influences the innate production capacity of cytokine levels following ex vivo stimulation by lipopolysaccharide (LPS), is currently unknown.

METHODS

Using data from the Netherlands Study of Depression and Anxiety (NESDA, n=1237), we examined whether CT (emotional neglect, emotional, physical, and sexual abuse before the age of 16), assessed by the Childhood Trauma Interview, was associated with levels in supernatants of interferon (IFN)γ, interleukin-2 (IL-2), IL-4, IL-6, IL-8, IL-10, IL-18, monocyte chemotactic protein-1 (MCP-1), macrophage inflammatory protein (MIP)-1α, MIP-1β, matrix metalloproteinase-2 (MMP-2), TNFα and TNFβ after ex vivo stimulation with LPS. Cytokines were analysed individually and cumulatively (overall inflammation index and number of cytokines in high-risk quartile (HRQ)) using linear regression analyses.

RESULTS

After adjustment for demographic, lifestyle, and health-related covariates, total CT severity was associated with the overall inflammation index (β = 0.085, P_FDR = 0.011), the number of cytokines in HRQ (β = 0.063, P_FDR = 0.036), and individual markers of IL-2 (β = 0.067, P_FDR = 0.036), IL-6 (β = 0.091 P_FDR = 0.011), IL-8 (β = 0.085 P_FDR = 0.011), IL-10 (β = 0.094 P_FDR = 0.011), MCP-1 (β = 0.081 P_FDR = 0.011), MIP-1α (β = 0.061 P_FDR = 0.047), MIP1-β (β = 0.077 P_FDR = 0.016), MMP-2 (β = 0.070 P_FDR = 0.027), and TNFβ (β = 0.078 P_FDR = 0.016). Associations were strongest for individuals with severe CT, reporting multiple types or higher frequencies of trauma. Half of the findings persisted after adjustment for psychiatric status. The findings were consistent across different CT types.

CONCLUSION

Childhood Trauma is associated with increased LPS-stimulated cytokine levels, with evidence for a dose-response relationship. Our results highlight a dysregulated innate immune system capacity in adults with CT, which could contribute to an increased vulnerability for psychopathology and somatic disorders across the lifespan.

Salivary immune markers are not associated with self-reported childhood maltreatment or psychopathology in adults

BACKGROUND

Psychological stress has repeatedly been found to be associated with pro-inflammatory markers in blood, and neuro-inflammation may play a role in the development of psychopathology after early life stress. Salivary immune testing is a novel method to non-invasively assess immune functioning. We examined a large range of salivary immune markers in relation to self-reported childhood maltreatment and psychopathology in an adult sample.

METHODS

Participants (N = 118, 51% female, mean age = 46.6 yrs, range 22-64) were drawn from a cross-sectional three-generation study, and supplied 2 ml of saliva via passive drool. They reported on childhood maltreatment experiences and on psychopathological symptoms in the last 6 months. Hair cortisol was additionally assessed in a subsample (n = 68). Levels of IL1ß, IL6, IL8, IFNγ, TNFα, tIgE, sIgA, FLCƛ, and FLCƙ were assessed.

RESULTS

Linear mixed model analyses showed that several salivary immune markers were associated with age (sIgA and IgE), BMI (sIgA, IL1ß, and IL6), sex (FLCs and IgE), and bad health (IL6, IL8, TNFα). No associations with (anti-inflammatory) medication use or oral health problems were found. Notably, no associations between the immune markers and self-reported childhood maltreatment, psychopathology, or hair cortisol were found.

CONCLUSIONS

Salivary immune measures were found to be sensitive to individual differences in age, sex, health and BMI. However. in the current sample there was no indication of inflammation in relation to chronic psychological stress. Larger studies, including participants with higher stress levels, are needed to further examine associations between salivary immune markers and psychological stress.

Early Life Adversity and Neuropsychiatric Disease: Differential Outcomes and Translational Relevance of Rodent Models

It is now well-established that early life adversity (ELA) predisposes individuals to develop several neuropsychiatric conditions, including anxiety disorders, and major depressive disorder. However, ELA is a very broad term, encompassing multiple types of negative childhood experiences, including physical, sexual and emotional abuse, physical and emotional neglect, as well as trauma associated with chronic illness, family separation, natural disasters, accidents, and witnessing a violent crime. Emerging literature suggests that in humans, different types of adverse experiences are more or less likely to produce susceptibilities to certain conditions that involve affective dysfunction. To investigate the driving mechanisms underlying the connection between experience and subsequent disease, neuroscientists have developed several rodent models of ELA, including pain exposure, maternal deprivation, and limited resources. These studies have also shown that different types of ELA paradigms produce different but somewhat overlapping behavioral phenotypes. In this review, we first investigate the types of ELA that may be driving different neuropsychiatric outcomes and brain changes in humans. We next evaluate whether rodent models of ELA can provide translationally relevant information regarding links between specific types of experience and changes in neural circuits underlying dysfunction.

Adverse Childhood Experiences Predict the Phenome of Affective Disorders and These Effects Are Mediated by Staging, Neuroimmunotoxic and Growth Factor Profiles

Adverse childhood experiences (ACEs) enhance pro-inflammatory and pro-oxidant responses. In affective disorders, recent precision nomothetic psychiatry studies disclosed new pathway phenotypes, including an ROI—reoccurrence of illness (ROI)—oxidative stress latent construct. The aim of the present study is to delineate a) whether ACEs sensitize the M1 macrophage, the T helper cells (Th)1, Th2, and Th17, the IRS (immune-inflammatory-responses system), the CIRS (compensatory immunoregulatory system), and the neuroimmunotoxic and growth factor (GF) profiles and whether they are associated with ROI and the phenome of affective disorders and b) the molecular pathways underpinning the effects of the ACEs. We collected supernatants of stimulated (5 μg/mL of PHA and 25 μg/mL of LPS) and unstimulated diluted whole blood in 20 healthy controls and 30 depressed patients and measured a panel of 27 cytokines/GF using a Luminex method. ACEs (comprising mental and physical trauma, mental neglect, domestic violence, family history of mental disease, and parent loss) are accompanied by the increased stimulated, but not unstimulated, production of M1, Th1, Th2, Th17, IRS, neuroimmunotoxic, and GF profiles and are strongly correlated with ROI and the phenome. A latent vector extracted from the ROI features (recurrent episodes and suicidal behaviors) and the IRS/neuroimmunotoxic/GF profiles explains 66.8% of the variance in the phenome and completely mediates the effects of ACEs on the phenome. Enrichment analysis showed that the ACE-associated sensitization of immune/GF profiles involves JAK-STAT, nuclear factor-κB, tumor necrosis factor-α, G-protein coupled receptor, PI3K/Akt/RAS/MAPK, and hypoxia signaling. In summary, the ACE-induced sensitization of immune pathways and secondary immune hits predicts the phenome of affective disorders.

Going beyond risk factor: Childhood maltreatment and associated modifiable targets to improve life-long outcomes in mood disorders

Childhood maltreatment increases risk for mood disorders and is associated with earlier onset-and more pernicious disease course following onset-of mood disorders. While the majority of studies to date have been cross-sectional, longitudinal studies are emerging and support the devastating role(s) childhood maltreatment has on development of, and illness course in, mood disorders. This manuscript extends prior reviews to emphasize more recent work, highlighting longitudinal data, and discusses treatment studies that provide clues to mechanisms that mediate disease risk, course, relapse, and treatment response. Evidence suggesting systemic inflammation, alterations in hypothalamic-pituitary-adrenal (HPA) axis function and corticotropin-releasing factor (CRF) neural systems, genetic and other familial factors as mechanisms that mediate risk and onset of, and illness course in, mood disorders following childhood maltreatment is discussed. Risky behaviors following maltreatment, e.g., substance use and unhealthy lifestyles, may further exacerbate alterations in the HPA axis, CRF neural systems, and systematic inflammation to contribute to a more pernicious disease course. More research on sex differences and the impact of maltreatment in vulnerable populations is needed. Future research needs to be aimed at leveraging knowledge on modifiable targets, going beyond childhood maltreatment as a risk factor, to inform prevention and treatment strategies and foster trauma-informed care.

Childhood Maltreatment and Psychiatric Comorbidity in Immune-Mediated Inflammatory Disorders

OBJECTIVE

To determine whether childhood maltreatment is associated with immune-mediated inflammatory disorders (IMIDs; multiple sclerosis [MS], inflammatory bowel disease [IBD], and rheumatoid arthritis [RA]). We further aimed to determine the relationship between maltreatment and psychiatric comorbidity in IMIDs and whether these relationships differed across IMID.

METHODS

Six hundred eighty-one participants (MS, 232; IBD, 216; RA, 130; healthy controls, 103) completed a structured psychiatric interview to identify psychiatric disorders, and the Childhood Trauma Questionnaire to evaluate five types of maltreatment: emotional abuse, physical abuse, sexual abuse, emotional neglect, and physical neglect. We evaluated associations between maltreatment, IMID, and psychiatric comorbidity using multivariable logistic regression models.

RESULTS

The prevalence of having ≥1 maltreatment was similar across IMID but higher than in controls (MS, 63.8%; IBD, 61.6%; RA, 62.3%; healthy controls, 45.6%). Emotional abuse was associated with having an IMID (adjusted odds ratio [aOR] = 2.37; 1.15-4.89). In the sex-specific analysis, this association was only present in women. History of childhood maltreatment was associated with a lifetime diagnosis of a psychiatric disorder in the IMID cohort (OR = 2.24; 1.58-3.16), but this association did not differ across diseases. In those with IMID, total types of maltreatments (aOR = 1.36; 1.17-1.59) and emotional abuse (aOR = 2.64; 1.66-4.21) were associated with psychiatric comorbidity.

CONCLUSIONS

Childhood maltreatment is more common in IMID than in a healthy population and is associated with psychiatric comorbidity. Given the high burden of psychiatric disorders in the IMID population, clinicians should be aware of the contribution of maltreatment and the potential need for trauma-informed care strategies.

Redefining peripheral inflammation signature in schizophrenia based on the real-world FACE-SZ cohort

BACKGROUND

Peripheral inflammation is associated with impaired prognosis in schizophrenia (SZ). Highly sensitive C-reactive protein (hs-CRP) is the most used inflammatory biomarker in daily practice. However, no consensual cut-off has been determined to date to discriminate patients with peripheral inflammation from those without.

AIMS

To determine if patients with peripheral inflammation between 1 and 3 mg/L had poorer outcomes compared to those with undetectable CRP (<1 mg/L).

METHOD

Consecutive participants of the FACE-SZ cohort with a hs-CRP < 3 mg/L were included in 10 expert academic centers with a national geographical distribution between 2010 and 2018. Potential sources of inflammation, socio-demographics, illness characteristics, current illness severity, functioning and quality of life and were reported following the FACE-SZ standardized protocol.

RESULTS

580 patients were included, of whom 226 (39%) were identified with low-grade inflammation defined by a hs-CRP between 1 and 3 mg/L. Overweight and lack of dental care were identified as potential sources of inflammation. After adjustment for these factors, patients with inflammation had more severe psychotic, depressive and aggressive symptomatology and impaired functioning compared to the patients with undetectable hs-CRP. No association with tobacco smoking or physical activity level has been found.

CONCLUSIONS

Patients with schizophrenia with hs-CRP level between 1 and 3 mg/L should be considered at risk for inflammation-associated disorders. Lowering weight and increasing dental care may be useful strategies to limit the sources of peripheral inflammation. Hs-CRP > 1 mg/L is a reliable marker to detect peripheral inflammation in patients with schizophrenia.

Preventive strategies for adolescent depression: What are we missing? A focus on biomarkers

Adolescent depression is an important global issue with several unmet needs that still must be addressed and, to date, there are only few effective preventive strategies to reduce the burden of this disorder worldwide. In this mini-review, the evidence and potential ways to improve an early detection will be discussed as well as prompt interventions by focusing on a better understanding of the risks underlying the developing of adolescent depression from both a sociodemographic and a biological perspective.

Linking childhood trauma and cytokine levels in depressed adolescents

BACKGROUND

Evidence supports raised circulating levels of inflammatory mediators, such as interleukin-6 (IL-6) and tumor necrosis factor (TNFα), among clinically depressed adults, although preliminary findings in adolescents are mixed. Independently, meta-analyses identify correlations between childhood trauma and elevated cytokine levels in adulthood. Here, we examine the possible role of individual differences in exposure to childhood trauma in contributing to variability in cytokine levels in depressed adolescents.

METHODS

52 depressed adolescents and 20 healthy adolescents completed measures of childhood trauma and provided blood for the assessment of plasma IL-6 and TNFα. Cross-sectional associations of childhood trauma and cytokine measures were assessed in both depressed and healthy adolescents, along with exploratory analysis of childhood trauma subtypes. Longitudinal relationships between childhood trauma and cytokine measures were also studied in an exploratory fashion within a subset of depressed participants (n = 36).

RESULTS

Higher childhood trauma (particularly emotional abuse) was positively associated with TNFα in depressed adolescents. Childhood trauma was not linked to longitudinal changes in cytokine levels.

DISCUSSION

In depressed adolescents, childhood trauma may relate to higher levels of the proinflammatory cytokine TNFα and contribute to heterogeneity in cytokine elevation among depressed adolescents. Such findings may ultimately help guide more effective individualized treatments for adolescents with depression.

Hypothalamus volume and DNA methylation of stress axis genes in major depressive disorder: A CAN-BIND study report

Dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis is considered one of the mechanisms underlying the development of major depressive disorder (MDD), but the exact nature of this dysfunction is unknown. We investigated the relationship between hypothalamus volume (HV) and blood-derived DNA methylation in MDD. We obtained brain MRI, clinical and molecular data from 181 unmedicated MDD and 90 healthy control (HC) participants. MDD participants received a 16-week standardized antidepressant treatment protocol, as part of the first Canadian Biomarker Integration Network in Depression (CAN-BIND) study. We collected bilateral HV measures via manual segmentation by two independent raters. DNA methylation and RNA sequencing were performed for three key HPA axis-regulating genes coding for the corticotropin-binding protein (CRHBP), glucocorticoid receptor (NR3C1) and FK506 binding protein 5 (FKBP5). We used elastic net regression to perform variable selection and assess predictive ability of methylation variables on HV. Left HV was negatively associated with duration of current episode (ρ = -0.17, p = 0.035). We did not observe significant differences in HV between MDD and HC or any associations between HV and treatment response at weeks 8 or 16, overall depression severity, illness duration or childhood maltreatment. We also did not observe any differentially methylated CpG sites between MDD and HC groups. After assessing functionality by correlating methylation levels with RNA expression of the respective genes, we observed that the number of functionally relevant CpG sites differed between MDD and HC groups in FKBP5 (χ² = 77.25, p < 0.0001) and NR3C1 (χ² = 7.29, p = 0.007). Cross-referencing functionally relevant CpG sites to those that were highly ranked in predicting HV in elastic net modeling identified one site from FKBP5 (cg03591753) and one from NR3C1 (cg20728768) within the MDD group. Stronger associations between DNA methylation, gene expression and HV in MDD suggest a novel putative molecular pathway of stress-related sensitivity in depression. Future studies should consider utilizing the epigenome and ultra-high field MR data which would allow the investigation of HV sub-fields.

Molecular Biomarkers for Pediatric Depressive Disorders: A Narrative Review

Depressive disorder in childhood and adolescence is a highly prevalent mood disorder that tends to recur throughout life. Untreated mood disorders can adversely impact a patient’s quality of life and cause socioeconomic loss. Thus, an accurate diagnosis and appropriate treatment is crucial. However, until now, diagnoses and treatments were conducted according to clinical symptoms. Objective and biological validation is lacking. This may result in a poor outcome for patients with depressive disorder. Research has been conducted to identify the biomarkers that are related to depressive disorder. Cumulative evidence has revealed that certain immunologic biomarkers including brain-derived neurotrophic factor (BDNF) and cytokines, gastrointestinal biomarkers, hormones, oxidative stress, and certain hypothalamus-pituitary axis biomarkers are associated with depressive disorder. This article reviews the biomarkers related to the diagnosis and treatment of pediatric depressive disorders. To date, clinical biomarker tests are not yet available for diagnosis or for the prediction of treatment prognosis. However, cytokines such as Interleukin-2, interferon-gamma, tumor necrosis factor-alpha, and BDNF have shown significant results in previous studies of pediatric depressive disorder. These biomarkers have the potential to be used for diagnosis, prognostic assessment, and group screening for those at high risk.

Stress-Related Dysfunction of Adult Hippocampal Neurogenesis-An Attempt for Understanding Resilience?

Newborn neurons in the adult hippocampus are regulated by many intrinsic and extrinsic cues. It is well accepted that elevated glucocorticoid levels lead to downregulation of adult neurogenesis, which this review discusses as one reason why psychiatric diseases, such as major depression, develop after long-term stress exposure. In reverse, adult neurogenesis has been suggested to protect against stress-induced major depression, and hence, could serve as a resilience mechanism. In this review, we will summarize current knowledge about the functional relation of adult neurogenesis and stress in health and disease. A special focus will lie on the mechanisms underlying the cascades of events from prolonged high glucocorticoid concentrations to reduced numbers of newborn neurons. In addition to neurotransmitter and neurotrophic factor dysregulation, these mechanisms include immunomodulatory pathways, as well as microbiota changes influencing the gut-brain axis. Finally, we discuss recent findings delineating the role of adult neurogenesis in stress resilience.

Biological correlates of early life stressful events in major depressive disorder

Major depressive disorder (MDD) is the most common psychiatric disorder and responds for important psychosocial consequences. Stressful life events, especially early life stress (ELS), contribute to an increased probability to develop MDD, leading in particular to severe and chronic manifestation and unfavorable treatment outcome. The association between ELS and MDD seems to have biological bases, consisting in dysregulations occurring at different levels. The aim of this narrative review is to propose an overview of the literature ranging from genetic, epigenetic, expression and protein to neuroimaging correlates underlying this relationship. A search on Pubmed of studies assessing biological correlates of ELS in MDD development, focusing on human studies conducted in both peripheral and brain tissues, was performed. Evidence indicated that the hypothalamic-pituitary-adrenal (HPA) axis and the serotonergic, dopaminergic, neurotrophin and oxytocin systems might play a role in the mediation between ELS and MDD. The most consistent results were found for genetic and epigenetic studies and indicated a joint involvement of the systems mentioned. Expression studies are less numerous and point to an involvement of stress-related systems. Concerning protein studies, the main mediators are markers related to the inflammatory and immune systems. Neuroimaging studies aiming at evaluating brain alterations connecting ELS and MDD in relation to biomarkers indicated the hippocampus, the amygdala and the frontal cortex as important anatomical mediators. These findings can build the bases for future research and clinical interventions; indeed, the clarification of biological mechanisms mediating the relationship between ELS and MDD can lead to new and individualized preventive and therapeutic possibilities.

Childhood Adversities and Salivary Cortisol Responses to the Trier Social Stress Test: A Systematic Review of Studies Using the Children Trauma Questionnaire (CTQ)

Alteration in cortisol response to acute social stressors has been hypothesized to mediate childhood adversities (CA) and increased morbidity in adulthood. However, the evidence supporting an association between CA and cortisol response to social stressors is inconclusive. The present review addressed this issue by reviewing the literature on CA and cortisol response to acute social stressors, with a focus on studies with adolescents or adults, using the Childhood Trauma Questionnaire (CTQ) to assess CA, and examining salivary cortisol response to the Trier Social Stress Test (TSST). Systematic searches of relevant articles in PsycINFO, PubMed, Web of Science and ScienceDirect in February and March 2020 identified 12 articles including 1196 participants with mean ages ranging from 15.3 to 52.3 yrs. across studies. CTQ scores were significantly associated with cortisol response in 2 studies. In addition, the physical abuse and emotional neglect subscales were associated with cortisol response respectively in 2 separate studies. The lack of association between CA and cortisol response calls for more longitudinal studies, and the use of formal records of maltreatment or informant reports in future research to complement information collected by retrospective measures. In addition, increased attention to biological mechanisms other than that associated with the regulation of cortisol in explaining the connection between CA and psychiatry morbidity is warranted.