Immune dysregulation in psychiatric disorders with and without exposure to childhood maltreatment: A transdiagnostic stratified meta-analysis

INTRODUCTION

Childhood maltreatment (CM), i.e. physical, psychological, or sexual abuse and neglect, affects approximately one third of the general population and is an important risk factor for all major psychiatric disorders. Exposure to CM also has a profound impact on immune function, with both factors independently implicated in the development and prognosis of different mental disorders. This study aims to 1) assess differences in immune markers among adults diagnosed with psychiatric disorders with and without a history of CM and 2) explore the role of CM as a mediating factor in immune abnormalities among psychiatric patients compared to non-psychiatric controls.

METHODS

A PRISMA-compliant systematic search of PubMed, Web of Science and Embase databases was performed until October 24th, 2024 for original studies that assessed immune markers in trauma-stratified adult psychiatric patients (PROSPERO ID CRD42021273059). We modelled random-effects meta-analyses to compare levels of pro-inflammatory (PIM), anti-inflammatory (AIM) and cellular immune markers (CIM) between traumatized (CM + ) and non-traumatized (CM-) individuals, and investigated exposure to CM as a mediating factor in the immune abnormalities among adult psychiatric patients compared to non-psychiatric controls. Secondary analyses were performed for diagnostic subgroups and individual immune markers. Study quality was assessed with the Newcastle Ottawa Scale.

RESULTS

We included data from 53 studies on n = 12,141 patients with mood disorders (MD), schizophrenia spectrum disorders (SSD), substance use disorders (SUD), eating disorders (ED) and anxiety disorders (AD). We uncovered a consistent transdiagnostic impact of CM on blood-based pro-inflammatory molecules (OR = 1.186; 95 % CI 1.030-1.365, p = 0.018) among patients with psychiatric disorders. This effect was not observed in the non-psychiatric controls included in the same studies. We did not find evidence of specific trauma-induced abnormalities in immune composite scores for separate diagnostic subgroups, except for PIM in SUD patients (OR = 2.324, 95 % CI 1.043-5.182, p = 0.039). Interleukin 6 (IL-6) was identified as a significant mediator between CM exposure and a psychiatric diagnosis in adulthood (OR = 1.609; 95 % CI 1.100-2.353, p = 0.014), while increases in C-reactive protein (CRP) and Interleukin 10 (IL-10) did not appear to be trauma-specific.

CONCLUSION

Our findings confirm a transdiagnostic impact of exposure to CM on increased pro-inflammatory molecular and cellular immune levels in psychiatric patients. IL-6 emerged as a crucial mediator, suggesting that CM leads to specific immune alterations predisposing individuals to psychiatric conditions. This meta-analysis highlights the role of trauma-induced immune abnormalities as a potentially crucial mechanism contributing to increased vulnerability towards mental illness later in life.

Immune-neuroendocrine crosstalk in mood and psychotic disorders: A meta-analysis and systematic review

Background

Bidirectional interactions between immune and neuroendocrine mechanisms are involved in mood and psychotic disorders, although individual studies report inconsistent and even contradictory findings on the nature of this crosstalk. Our objective was to perform an up to date systematic review and meta-analysis of the association between hypothalamic-pituitary-adrenal (HPA) axis and immune system functioning in mood and psychotic disorders.

Methods

We searched the Pubmed, Web of Science and Embase databases for studies reporting correlations between one or more HPA- and immune markers (IM) in patients with mood or psychotic disorders. We analyzed unchallenged correlations as well as challenge studies investigating the HPA-immune interaction through dexamethasone (DEX) and/or CRH suppression, HPA-mediated challenge of immune cell proliferation, immune challenges, or psychological stressors. Finally, genetic studies focusing on HPA x immune interrelation were evaluated. For meta-analyzable data, three primary outcome measures were defined for immune functioning, namely the pro-inflammatory index (PII) and anti-inflammatory index (AII) for the molecular IM and a composite cellular immune marker score (CCIM) for the cellular IM. Secondary analyses were performed for the individual molecular and cellular IM. Heterogeneity was evaluated with the I2 statistic. Meta-regression analyses were performed to evaluate the impact of potential covariates (publication year, gender, age, symptom severity) on the primary outcome analyses.

Results

93 studies (n = 8226) were included, of which 50 (n = 5649) contained meta-analyzable data. The majority of the included studies (k = 72) investigated major depressive disorder (MDD) patients, nineteen schizophrenia spectrum disorders (SSD) and six bipolar disorder (BD). Under physiological conditions, a poor association was found between cortisol and the PII only in the unmedicated subsample of MDD (k = 8; n = 425; r = .205; z = 2.151; p = .031) and the medicated subsample of SSD (k = 4; n = 152; r = .0.237; z = 2.314; p = .021). No significant correlation was found in MDD between the AII and cortisol (k = 3; n = 1243; r = .005; z = .188; p = .851). Similar results were found for the association between immune cell numbers and cortisol in both MDD (k = 10; n = 773; r = -.005; z = -.113; p = .894) and SSD (k = 4; n = 99; r = .167; z = 1.356; p = .175). A total of 42 studies discussed post-challenge associations between immune alterations and HPA disturbances, of which 12 (n = 389; all MDD) contained meta-analyzable data and 37 entered the systematic review (n = 1783). No post-DEX correlations were found between cortisol and PII (k = 3; n = 105; r = .074; z = .355; p = .722) or CCIM (k = 5; n = 259; r = -.153; z = -1.294; p = .196). However, a significant association was found between post-DEX cortisol/ACTH and PII produced by stimulated blood cells in vitro (k = 3; n = 61; r = .508; z = 4.042; p < .001) as well as for cortisol and CCIM score in MDD after in vitro mitogen stimulation (k = 4; n = 90; r = -.309; z = -2498; p = .012). Following a psychological stressor (k = 6; n = 121), cortisol responses tended to be blunted in all included pathologies, while immune activation was comparable to healthy controls. Genetic studies (k = 7; n = 464) demonstrate altered gene expression of glucocorticoid receptors (GR) in peripheral immune cells in MDD. Heterogeneity over studies tended to be moderate to high.

Discussion

The main limitations are the heterogeneity of outcome measures (both HPA and IM) and small sample sizes of the included studies. We conclude that, in physiological conditions, associations between HPA-axis and molecular or cellular IM are absent or poor in both MDD and SSD and psychotropic medication may influence this crosstalk differently in both patient groups. Studies using challenge paradigms in MDD populations did reveal differences in the HPA-immune crosstalk. The normally expected decrease in lymphocytes after DEX distribution tended to be less pronounced in MDD, especially in glucocorticoid-insensitive non-suppressors. It is recommended that future studies should be properly powered and assess HPA functioning using multiple cortisol assessments. Challenge studies are probably more useful than baseline biomarker studies and cellular IM are more informative than molecular IM. It is recommended to broadly assess leucocyte function and, when possible, perform subgroup analyses based on HPA- and/or immune function.

Unveiling Transitions in Disease States: Study of Depressive and Anxiety Symptom Networks over Time

Background

Major depressive disorder (MDD) and anxiety disorders (AD) have high degrees of comorbidity and show great overlap in symptoms. The analysis of covarying depressive- and anxiety symptoms in longitudinal, sparse data panels has received limited attention. Dynamic time warping (DTW) analysis may help to provide new insights into symptom network properties based on diagnostic- and disease-state stability criteria.

Materials and Methods

In the Netherlands Study of Depression and Anxiety depressive-, anxiety-, and worry symptoms were assessed four or five times over the course of 9 years using self-report questionnaires. The sample included 1,649 participants at baseline, comprising controls (n = 360), AD patients (n = 158), MDD patients (n = 265), and comorbid AD-MDD patients (n = 866). With DTW, 1,649 distance matrices were calculated, which yielded symptom networks and enabling comparison of network densities among subgroups.

Results

The mean age of the sample was 41.5 years (standard deviations, 13.2), of whom 66.4% were female. The largest distance was between worry symptoms and physiological arousal symptoms, implicating the most dissimilar dynamics over time. The network density in the groups, from lowest to highest, followed the order: controls, AD, MDD, and comorbid AD-MDD. The comorbid group showed strongly connected mood and cognitive symptoms, which contrasted with the more strongly connected somatic and arousal symptoms in the AD and MDD groups. Groups that showed more transitions in disease states over follow-up, regardless of the diagnoses, had the highest network density compared to more stable states of health or disease (beta for quadratic term = -0.095; P  < 0.001).

Conclusions

Symptom networks over time can be visualized by applying DTW methods on sparse panel data. Network density was highest in patients with comorbid anxiety and depressive disorders and those with more instability in disease states, suggesting that a stronger internal connectivity may facilitate "critical transitions" within the complex systems framework.