Antidepressant psychopharmacology: is inflammation a future target?

Understanding and treating postpartum depression: a narrative review

Postpartum depression (PPD) is an increasingly prevalent but still poorly characterized disorder. Causal and modulating factors include hormones fluctuations, such as estrogen, progesterone, and allopregnolone, pathways imbalances, such as oxytocin and kynurenine, chronobiological factors, and brain imaging alterations. Treatment may differ from the traditional major depression management, while selective serotonin reuptake inhibitors such as sertraline are commonly used and suggested by guidelines, neurosteroids such as brexanolone and the more convenient zuranolone have been recently approved. Newer neurosteroids such as ganaxolone, valaxanolone, and lysaxanolone are currently under development, but also esketamine and psychedelics are promising potential treatments. Other somatic treatments including brain stimulation techniques and light therapy also showed benefit. PPD is therefore increasingly understood as, at least partially, independent from major depressive disorder. Specific and individualized treatments including pharmacological and non-pharmacological therapies are progressively being introduced in the routine clinical practice.

Exploring the dissociative subtype of PTSD: The role of early-life trauma, cortisol, and inflammatory profiles

Post-traumatic stress disorder (PTSD) is a heterogeneous mental health condition, characterized by diverse symptom profiles and biological underpinnings. A dissociative subtype of PTSD has been identified, though the potential risk factors and underlying neurobiology are yet to be understood. The current study comprised Canadian Armed Forces (CAF) members and Veterans with a history of deployment, and with diagnoses of non-dissociative (n = 31) and dissociative subtypes of PTSD (n = 19), in addition to non-deployed healthy controls (n = 14). Participants completed questionnaires assessing clinical symptoms and experiences of trauma, and provided saliva and blood samples for cortisol and inflammatory marker assessments. Individuals with dissociative PTSD displayed elevated PTSD and depression symptom severity, and greater reports of specific forms of childhood trauma compared to individuals with non-dissociative PTSD and controls. Morning cortisol was elevated in both PTSD groups compared to controls, however the PTSD groups did not differ from one another. Evening cortisol concentrations were elevated in both PTSD groups compared to controls, and in the dissociative PTSD subtype compared to the non-dissociative PTSD subtype when controlling for depression symptoms. PTSD diagnostic group moderated the relationship between awakening cortisol levels and PTSD symptom severity, such that the non-dissociative PTSD group displayed a negative correlation between awakening cortisol levels and PTSD symptom severity, while no significant relation was identified in the dissociative PTSD group. C-reactive protein (CRP) levels did not differ across diagnostic groups when accounting for body mass index (BMI). However, CRP positively correlated with depressive symptoms only among individuals with dissociative PTSD. Together, examining PTSD subtypes may help inform more effective and personalized treatment strategies in the future.

Sex-Specific Inflammatory Profiles Affect Neuropsychiatric Issues in COVID-19 Survivors

Post-COVID syndrome has unveiled intricate connections between inflammation, depressive psychopathology, and cognitive impairment. This study investigates these relationships in 101 COVID-19 survivors, focusing on sex-specific variations. Utilizing path modelling techniques, we analyzed the interplay of a one-month 48-biomarker inflammatory panel, with three-months of depressive symptoms and cognitive performance. The findings indicate that cognitive impairment is influenced by both inflammation and depression in the overall cohort. However, prominent sex-specific differences emerged. In females, a lingering imbalance between pro- and anti-inflammatory responses-likely reflecting the long-lasting immune alterations triggered by COVID-19-significantly affects cognitive functioning and shows a marginal, though not statistically significant, association with depressive symptoms. This suggests that a mixed inflammatory profile may contribute to these outcomes. Conversely, in males, inflammation was inversely associated with depression severity, with protective effects from regulatory mediators (IL-2, IL-4, IL-6, IL-15, LIF, TNF-α, β-NGF) against depression. In males, cognitive impairment appeared to be driven mainly by depressive symptoms, with minimal influence from inflammatory markers. These results highlight distinct sex-specific pathways in immune and inflammatory responses post-COVID-19, potentially shaped by endocrine mechanisms. The findings suggest that persistent inflammation may foster long-term neuropsychiatric sequelae, possibly through its effects on the brain, and underscore the need for sex-tailored therapeutic strategies to address the lasting impact of COVID-19.

Specific symptomatology profile associated with treatment resistant depression: A multicentric study from the Group for the Study of Resistant Depression with a focus on sex

BACKGROUND

Clinical predictors of treatment-resistant depression could improve treatment strategies. Depressive symptom profiles at baseline are potential outcome predictors, but little evidence is available, and sex-specific profiles have been scarcely investigated.

METHODS

Baseline symptom scores of 1294 patients with major depressive disorder were assessed by the Montgomery-Åsberg depression rating scale (MADRS) as part of a multicenter study by the "Group for the Studies of Resistant Depression". Treatment outcomes were assessed according to the MADRS after ≥4 weeks of naturalistic treatment. We tested if individual MADRS item scores at baseline were associated with treatment outcome in the whole sample and in sex-stratified subgroups.

RESULTS

A specific baseline symptom profile was associated with non-response in the whole sample. In particular, apparent and reported sadness, reduced sleep, lassitude, inability to feel, and pessimistic thoughts were the only MADRS items that scored higher at baseline in patients with subsequent lack of response. In the sex-stratified analysis, females showed a similar profile overall, however they showed higher baseline levels of inner tension, inability to feel, and pessimistic thoughts compared to males, and these symptoms were associated with lack of response in females but not in males. Neurovegetative symptoms were poorly predictive. Overall baseline severity related to poor response.

LIMITATIONS

This is a post-hoc analysis. The naturalistic design of the study with a retrospective assessment is potential limitations.

CONCLUSION

A specific baseline symptom profile characterized by higher sadness, reduced sleep and anhedonic features may be indicative of poor treatment outcome. Females showed a distinctive baseline profile associated with poor response.

Effects of kynurenine pathway metabolites on choroid plexus volume, hemodynamic response, and spontaneous neural activity: A new mechanism for disrupted neurovascular communication and impaired cognition in mood disorders

Major Depressive Disorder (MDD) and Bipolar Disorder (BD) involve alterations of immune-inflammatory setpoints that activate the kynurenine pathway (KP), affecting serotoninergic and glutamatergic neurotransmission through indoleamine-2,3-dioxygenase (IDO) activity. This process produces metabolites like Kynurenine (Kyn), 3-Hydroxykynurenine (3-HK), Quinolinic acid (QuinA), and Kynurenic acid (KynA), these last two acting as agonist and antagonist at glutamatergic N-methyl-D-aspartate receptors (NMDARs), respectively. NMDARs, expressed in the choroid plexus (ChP) and arteriolar smooth muscle cells, regulate blood-brain-barrier permeability and cerebral artery dilation, suggesting that KP may influence neurovascular coupling, aligning blood flow with neural energy demand. KP's role in modulating vascular tone supports this hypothesis. Altered fractional amplitude of low-frequency fluctuations (fALFF) and disrupted default mode network (DMN) activity in mood disorders are linked to cognitive deficits possibly through neurovascular uncoupling like in neurological diseases. This makes fALFF and hemodynamic response function (HRF) potential indicators of these changes. We investigated KP associations with ChP volumes, functional-MRI at rest measures like spontaneous neural activity (fALFF) and hemodynamic response function (HRF) parameters within the default mode network (DMN), and cognitive performance in 42 MDD and 36 BD inpatients experiencing a depressive episode. Results revealed that lower QuinA/KynA ratios and higher KynA levels predict larger ChP volumes. Higher KYN and 3-HK levels, along with lower KynA levels, were associated with increased DMN fALFF and shorter time-to-peak (TTP) in HRF, suggesting altered neurovascular coupling. Mediation analyses indicated that KP metabolites influenced cognitive performance through their effects on resting state measures, affecting global cognitive functioning score, verbal fluency, and psychomotor coordination. These findings suggest that KP metabolites modulate brain function and structure via NMDAR-mediated pathways and vascular-based mechanisms, offering insights into the cognitive impairments observed in mood disorders and identifying potential therapeutic targets.

PKR Inhibition Prevents Neuroinflammation and Rescues Depressive-Like Behaviors via BDNF/TrkB Signaling

PKR, a kinase implicated in inflammation, accumulates in the brain, but its role in neuroinflammation-related depression is poorly understood. This study aimed to investigate whether pharmacological PKR inhibition using C16 (PKR inhibitor) could reverse LPS-induced neuroinflammation and depressive-like behaviors. Mice (C57BL/6J, 20-22 g, 6-8 weeks old) were administered LPS intraperitoneally for three days to induce depressive-like behavior and neuroinflammation. Simultaneously, mice were treated with C16 (a pharmacological PKR inhibitor) intraperitoneally for the same duration, followed by behavioral assessments. After euthanasia, brain-hippocampus tissues were collected for biochemical analysis. To validate these in vivo findings, BV2 and HT22 cells were cultured and subjected to pharmacological and biochemical analysis. LPS treatment significantly increased hippocampal neuroinflammation (GFAP/IBA-1 p < 0.001), cytokine production (IL-1β, IL-6, TNF-α, p < 0.05), PKR phosphorylation (p < 0.05), and inflammatory signaling (NLRP3/ASC, p < 0.001). Concomitantly, LPS exposure induced depressive-like symptoms (p < 0.001), impaired synaptic function (Synasin-1/SNAP25, p < 0.05), spine numbers (p < 0.001), and downregulated brain-derived neurotrophic factor (BDNF) /TrkB signaling (p < 0.001). Importantly, these effects were attenuated by C16, a PKR inhibitor. C16 also reduced LPS-induced ER stress markers in the hippocampus (p < 0.05). Interestingly, K252a, a BDNF/TrkB inhibitor, reversed the protective effects of C16, increasing both neuroinflammation (p < 0.001) and depressive symptoms (p < 0.001) in LPS-treated mice. Notably, in vitro studies using BV2 and HT22 cells corroborated these findings. In conclusion, these findings suggest that PKR is critical in mediating LPS-induced neuroinflammation and depressive-like behaviors, potentially through interactions with BDNF/TrkB signaling.

Circulating inflammatory markers predict depressive symptomatology in COVID-19 survivors

Growing evidence suggests the neurobiological mechanism upholding post-COVID-19 depression mainly relates to immune response and subsequent unresolved low-grade inflammation. Herein we exploit a broad panel of cytokines serum levels measured in COVID-19 survivors at one- and three-month since infection to predict post-COVID-19 depression. 87 COVID survivors were screened for depressive symptomatology at one- and three-month after discharge through the Beck Depression Inventory (BDI-13) and the Zung Self-Rating Depression Scale (ZSDS) at San Raffaele Hospital. Blood samples were collected at both timepoints and analyzed through Luminex. We entered one-month 42 inflammatory compounds into two separate penalized logistic regression models to evaluate their reliability in identifying COVID-19 survivors suffering from clinical depression at the two timepoints, applied within a machine learning routine. Delta values of analytes lowering between timepoints were entered in a third model predicting presence long-term depression. 5000 bootstraps were computed to determine significance of predictors. The cross-sectional model reached a balance accuracy (BA) of 76 % and a sensitivity of 70 %. Post-COVID-19 depression was predicted by high levels of CCL17, CCL22. On the other hand, CXCL10, CCL2, CCL3, CCL8, CXCL5, CCL15, CCL23, CXCL13, and GM-CSF showed protective effects. The longitudinal model obtained good performance as well (BA = 74 % and sensitivity = 68 %), revealing CXCL16 and CCL25 as additional drivers of clinical depression. Moreover, dynamic changes of analytes over time accurately predicted long-term depression (BA = 76 % and sensitivity = 75 %). Our findings unveil a putative immune profile upholding post-COVID-19 depression, thus reinforcing the need to deepen molecular mechanisms to appropriately target depression.

Abnormal choroid plexus, hippocampus, and lateral ventricles volumes as markers of treatment-resistant major depressive disorder

AIM

One-third of patients with major depressive disorder (MDD) do not achieve full remission and have high relapse rates even after treatment, leading to increased medical costs and reduced quality of life and health status. The possible specificity of treatment-resistant depression (TRD) neurobiology is still under investigation, with risk factors such as higher inflammatory markers being identified. Given recent findings on the role of choroid plexus (ChP) in neuroinflammation and hippocampus in treatment response, the aim of the present study was to evaluate inflammatory- and trophic-related differences in these regions along with ventricular volumes among patients with treatment-sensitive depression (TSD), TRD, and healthy controls (HCs).

METHODS

ChP, hippocampal, and ventricular volumes were assessed in 197 patients with MDD and 58 age- and sex-matched HCs. Volumes were estimated using FreeSurfer 7.2. Treatment resistance status was defined as failure to respond to at least two separate antidepressant treatments. Region of interest volumes were then compared among groups.

RESULTS

We found higher ChP volumes in patients with TRD compared with patients with TSD and HCs. Our results also showed lower hippocampal volumes and higher lateral ventricular volumes in TRD compared with both patients without TRD and HCs.

CONCLUSIONS

These findings corroborate the link between TRD and neuroinflammation, as ChP volume could be considered a putative marker of central immune activity. The lack of significant differences in all of the region of interest volumes between patients with TSD and HCs may highlight the specificity of these features to TRD, possibly providing new insights into the specific neurobiological underpinnings of this condition.

Exploring the use of immunomethylomics in the characterization of depressed patients: A proof-of-concept study

Alterations in DNA methylation and inflammation could represent valid biomarkers for the stratification of patients with major depressive disorder (MDD). This study explored the use of DNA-methylation based immunological cell-type profiles in the context of MDD and symptom severity over time. In 119 individuals with MDD, DNA-methylation was assessed on whole blood using the Illumina Infinium MethylationEPIC 850 k BeadChip. Quality control and data processing, as well as cell type estimation was conducted using the RnBeads package. The cell type composition was estimated using epigenome-wide DNA methylation signatures, applying the Houseman method, considering six cell types (neutrophils, natural killer cells (NK), B cells, CD4+ T cells, CD8+ T cells and monocytes). Two cytokines (IL-6 and IL-1β) and hsCRP were quantified in serum. We performed a hierarchical cluster analysis on the six estimated cell-types and tested the differences between these clusters in relation to the two cytokines and hsCRP, depression severity at baseline, and after 6 weeks of treatment (celecoxib/placebo + vortioxetine). We performed a second cluster analysis with cell-types and cytokines combined. ANCOVA was used to test for differences across clusters. We applied the Bonferroni correction. After quality control, we included 113 participants. Two clusters were identified, cluster 1 was high in CD4+ cells and NK, cluster 2 was high in CD8+ T-cells and B-cells, with similar fractions of neutrophils and monocytes. The clusters were not associated with either of the two cytokines and hsCRP, or depression severity at baseline, but cluster 1 showed higher depression severity after 6 weeks, corrected for baseline (p = 0.0060). The second cluster analysis found similar results: cluster 1 was low in CD8+ T-cells, B-cells, and IL-1β. Cluster 2 was low in CD4+ cells and natural killer cells. Neutrophils, monocytes, IL-6 and hsCRP were not different between the clusters. Participants in cluster 1 showed higher depression severity at baseline than cluster 2 (p = 0.034), but no difference in depression severity after 6 weeks. DNA-methylation based cell-type profiles may be valuable in the immunological characterization and stratification of patients with MDD. Future models should consider the inclusion of more cell-types and cytokines for better a prediction of treatment outcomes.

Understanding immune system dysfunction and its context in mood disorders: psychoneuroimmunoendocrinology and clinical interventions

Mood disorders include a set of psychiatric manifestations of increasing prevalence in our society, being mainly represented by major depressive disorder (MDD) and bipolar disorder (BD). The etiopathogenesis of mood disorders is extremely complex, with a wide spectrum of biological, psychological, and sociocultural factors being responsible for their appearance and development. In this sense, immune system dysfunction represents a key mechanism in the onset and pathophysiology of mood disorders, worsening mainly the central nervous system (neuroinflammation) and the periphery of the body (systemic inflammation). However, these alterations cannot be understood separately, but as part of a complex picture in which different factors and systems interact with each other. Psychoneuroimmunoendocrinology (PNIE) is the area responsible for studying the relationship between these elements and the impact of mind-body integration, placing the immune system as part of a whole. Thus, the dysfunction of the immune system is capable of influencing and activating different mechanisms that promote disruption of the psyche, damage to the nervous system, alterations to the endocrine and metabolic systems, and disruption of the microbiota and intestinal ecosystem, as well as of other organs and, in turn, all these mechanisms are responsible for inducing and enhancing the immune dysfunction. Similarly, the clinical approach to these patients is usually multidisciplinary, and the therapeutic arsenal includes different pharmacological (for example, antidepressants, antipsychotics, and lithium) and non-pharmacological (i.e., psychotherapy, lifestyle, and electroconvulsive therapy) treatments. These interventions also modulate the immune system and other elements of the PNIE in these patients, which may be interesting to understand the therapeutic success or failure of these approaches. In this sense, this review aims to delve into the relationship between immune dysfunction and mood disorders and their integration in the complex context of PNIE. Likewise, an attempt will be made to explore the effects on the immune system of different strategies available in the clinical approach to these patients, in order to identify the mechanisms described and their possible uses as biomarkers.

The revival of psilocybin between scientific excitement, evidence of efficacy, and real-world challenges

The revival of psilocybin in psychopharmacological research heralds a potential paradigm shift for treating mood and anxiety disorders, and other psychiatric conditions beyond the psychotic spectrum. This critical review evaluates current evidence on psilocybin's efficacy, juxtaposing potential benefits with the practical aspects of psychedelic-assisted psychotherapy (PAP) and the methodological constraints of existing research.An electronic literature search was conducted using PubMed/MEDLINE, selecting studies published up to December 2023 that explored the clinical use of psilocybin in mood and anxiety disorders, obsessive-compulsive disorder, post-traumatic stress disorder, and substance use disorder. Despite promising preliminary results suggesting psilocybin's efficacy in alleviating depression and anxiety, as well as obsessions, compulsions, and addictive behaviors, significant evidence gaps persist. These include evaluating the efficacy of psilocybin compared to standard antidepressants or anxiolytic molecules and identifying patient subpopulations that might benefit most from PAP. Concerns about psilocybin's safety, long-term efficacy, and optimal dosage remain unclear due to previous trials' limitations. Real-world implementation faces challenges, including infrastructural requirements, personnel training, and unresolved legal and ethical issues. This paper argues for further research to substantiate the evidence base, emphasizing the need for larger studies that overcome current methodological limitations and explore psilocybin's full therapeutic potential. While psilocybin holds promise for psychiatry, its successful translation from research to clinical practice demands more robust evidence on efficacy, safety, and methodological rigor. In addition, other factors, such as cultural stigma and legal/ethical issues, need to be successfully addressed to facilitate psilocybin's implementation in healthcare systems.

The emergence of antidepressant drugs targeting GABAA receptors: A concise review

Depression is among the most common psychiatric illnesses, which imposes a major socioeconomic burden on patients, caregivers, and the public health system. Treatment with classical antidepressants (e.g. tricyclic antidepressants and selective serotonine reuptake inhibitors), which primarily affect monoaminergic systems has several limitations, such as delayed onset of action and moderate efficacy in a relatively large proportion of depressed patients. Furthermore, depression is highly heterogeneus, and its different subtypes, including post-partum depression, involve distinct neurobiology, warranting a differential approach to pharmacotherapy. Given these shortcomings, the need for novel antidepressants that are superior in efficacy and faster in onset of action is fully justified. The development and market introduction of rapid-acting antidepressants has accelerated in recent years. Some of these new antidepressants act through the GABAergic system. In this review, we discuss the discovery, efficacy, and limitations of treatment with classic antidepressants. We provide a detailed discussion of GABAergic neurotransmission, with a special focus on GABAA receptors, and possible explanations for the mood-enhancing effects of GABAergic medications (in particular neurosteroids acting at GABAA receptors), and, ultimately, we present the most promising molecules belonging to this family which are currently used in clinical practice or are in late phases of clinical development.

Inflammatory mediators in major depression and bipolar disorder

Major depressive disorder (MDD) and bipolar disorder (BD) are highly disabling illnesses defined by different psychopathological, neuroimaging, and cognitive profiles. In the last decades, immune dysregulation has received increasing attention as a central factor in the pathophysiology of these disorders. Several aspects of immune dysregulations have been investigated, including, low-grade inflammation cytokines, chemokines, cell populations, gene expression, and markers of both peripheral and central immune activation. Understanding the distinct immune profiles characterizing the two disorders is indeed of crucial importance for differential diagnosis and the implementation of personalized treatment strategies. In this paper, we reviewed the current literature on the dysregulation of the immune response system focusing our attention on studies using inflammatory markers to discriminate between MDD and BD. High heterogeneity characterized the available literature, reflecting the heterogeneity of the disorders. Common alterations in the immune response system include high pro-inflammatory cytokines such as IL-6 and TNF-α. On the contrary, a greater involvement of chemokines and markers associated with innate immunity has been reported in BD together with dynamic changes in T cells with differentiation defects during childhood which normalize in adulthood, whereas classic mediators of immune responses such as IL-4 and IL-10 are present in MDD together with signs of immune-senescence.

Post-COVID Trajectory of Pentraxin 3 Plasma Levels Over 6 Months and Their Association with the Risk of Developing Post-Acute Depression and Anxiety

BACKGROUND AND OBJECTIVES

Clinical manifestations of coronavirus disease 2019 (COVID-19) often persist after acute disease resolution. Underlying molecular mechanisms are unclear. The objective of this original article was to longitudinally measure plasma levels of markers of the innate immune response to investigate whether they associate with and predict post-COVID symptomatology.

METHODS

Adult patients with previous severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection during the first pandemic wave who underwent the 6-month multidisciplinary follow-up were included. Plasma levels of pentraxin 3 (PTX3), the complement components C3a and C5a, and chitinase-3 like-protein-1 (CHI3L1) were measured at hospital admission during acute disease (baseline) and at 1 and 6 months after hospital discharge. Associations with post-COVID-19 sequelae at 6 months were investigated using descriptive statistic and multiple regression models.

RESULTS

Ninety-four COVID-19 patients were included. Baseline PTX3, C5a, C3a, and CHI3L1 did not predict post-COVID-19 sequelae. The extent of the reduction of PTX3 over time (delta PTX3) was associated with lower depressive and anxiety symptoms at 6 months (both p < 0.05). When entering sex, age, need for intensive care unit or non-invasive ventilation during hospital stay, psychiatric history, and baseline PTX3 as nuisance covariates into a generalized linear model (GLM), the difference between baseline and 6-month PTX3 levels (delta PTX3) significantly predicted depression (χ2 = 4.66, p = 0.031) and anxiety (χ2 = 4.68, p = 0.031) at 6 months. No differences in PTX3 levels or PTX3 delta were found in patients with or without persistent or new-onset other COVID-19 symptoms or signs at 6 months. Plasma levels of C3a, C5a, and CHI3L1 did not correlate with PTX3 levels at either time point and failed to associate with residual or de novo respiratory or systemic clinical manifestations of the disease at 6 months.

CONCLUSIONS

A lower reduction of plasma PTX3 after acute COVID-19 associates with the presence of depression and anxiety, suggesting an involvement of inflammation in post-COVID-19 psychopathology and a potential role of PTX3 as a biomarker.

Mental health in patients affected by atopic dermatitis: which effects of treatment with dupilumab?

Atopic dermatitis (AD) is an inflammatory skin disease. Patients with AD are prone to develop anxiety and mood disorders. Aim of this study is to investigate if treatment with dupilumab may improve mental health status of patients affected by AD. A total of 66 patients with severe AD were included: 24 subjects were candidate or have just started (one month) treatment with dupilumab, and 42 have been in treatment for one year. 25.8%, 30.3%, and 45.5% of the total sample showed, respectively, clinically significant anxiety, depression, and symptoms of Internet addiction. Patients with anxiety symptoms resulted to have more severe AD, more sleep problems ( P  = 0.028), less quality of life ( P  = 0.001), more severe depressive symptoms ( P  < 0.001), to be more frequently women ( P  = 0.016), to be less frequently treated with dupilumab for one year ( P  = 0.025). Similarly, patients with clinically significant depressive symptoms resulted to have more severe AD, more sleep problems ( P  = 0.003), less quality of life ( P  < 0.001), more severe anxiety symptoms ( P  < 0.001), to be less frequently treated with dupilumab for one year ( P  = 0.008). Patients with AD treated for one year with dupilumab showed a better mental health profile in terms of less severe anxiety and depression with respect to their counterparts.

Low-dose interleukin 2 antidepressant potentiation in unipolar and bipolar depression: Safety, efficacy, and immunological biomarkers

Immune-inflammatory mechanisms are promising targets for antidepressant pharmacology. Immune cell abnormalities have been reported in mood disorders showing a partial T cell defect. Following this line of reasoning we defined an antidepressant potentiation treatment with add-on low-dose interleukin 2 (IL-2). IL-2 is a T-cell growth factor which has proven anti-inflammatory efficacy in autoimmune conditions, increasing thymic production of naïve CD4 + T cells, and possibly correcting the partial T cell defect observed in mood disorders. We performed a single-center, randomised, double-blind, placebo-controlled phase II trial evaluating the safety, clinical efficacy and biological responses of low-dose IL-2 in depressed patients with major depressive (MDD) or bipolar disorder (BD). 36 consecutively recruited inpatients at the Mood Disorder Unit were randomised in a 2:1 ratio to receive either aldesleukin (12 MDD and 12 BD) or placebo (6 MDD and 6 BD). Active treatment significantly potentiated antidepressant response to ongoing SSRI/SNRI treatment in both diagnostic groups, and expanded the population of T regulatory, T helper 2, and percentage of Naive CD4+/CD8 + immune cells. Changes in cell frequences were rapidly induced in the first five days of treatment, and predicted the later improvement of depression severity. No serious adverse effect was observed. This is the first randomised control trial (RCT) evidence supporting the hypothesis that treatment to strengthen the T cell system could be a successful way to correct the immuno-inflammatory abnormalities associated with mood disorders, and potentiate antidepressant response.

Higher Seasonal Variation of Systemic Inflammation in Bipolar Disorder

Seasonal rhythms affect the immune system. Evidence supports the involvement of immuno-inflammatory mechanisms in bipolar disorder (BD), with the neutrophil to lymphocyte ratio (NLR), and the systemic immune-inflammatory index (SII; platelets × neutrophils/lymphocytes) consistently reported to be higher in patients with BD than in HC, but seasonal rhythms of innate and adaptive immunity have never been studied. We retrospectively studied NLR and SII in 824 participants divided into three groups: 321 consecutively admitted inpatients affected by a major depressive episode in course of BD, and 255 consecutively admitted inpatients affected by obsessive-compulsive disorder (OCD; positive psychiatric control), and 248 healthy controls (HC). Patients with BD showed markedly higher markers of systemic inflammation in autumn and winter, but not in spring and summer, in respect to both HC and patients with OCD, thus suggesting a specific effect of season on inflammatory markers in BD, independent of a shared hospital setting and drug treatment. Given that systemic inflammation is emerging as a new marker and as target for treatment in depressive disorders, we suggest that seasonal rhythms should be considered for tailoring antidepressant immuno-modulatory treatments in a precision medicine approach.

The Effect of Antidepressant Treatment on Neurocognitive Functions, Redox and Inflammatory Parameters in the Context of COVID-19

Inflammation is an important component of the etiopathology of depression that uses oxidative and nitrosative stress (O&NS) and elevated inflammatory markers. SARS-CoV-2 infection is also associated with abnormal inflammatory processes, which may impair effective treatment of depression in COVID-19 survivors. In the presented study, thirty-three hospitalized patients with major depressive disorder (MDD) were started on antidepressant treatment, and twenty-one were re-evaluated after 4-6 weeks. The control group consisted of thirty healthy volunteers. All participants underwent neuropsychiatric evaluation, biochemical blood and urine analyses. The results of the research demonstrated positive correlations of the Hamilton Depression Rating Scale (HAM-D) scores with serum catalase (CAT) and urinary S-Nitrosothiols levels, and the Beck Depression Inventory (BDI) scores with serum reduced glutathione (GSH) and superoxide dismutase (SOD) levels. Depressed patients with a history of COVID-19 prior to the treatment had higher urinary nitric oxide (NO) levels and lower serum glutathione peroxidase (GPx) levels. In the control group, COVID-19 survivors had higher levels of urinary N-formylkynurenine (NFK). Our results suggest that the antidepressant treatment has a modulating effect on O&NS, reduces depressive symptoms and improves cognitive functions The present study does not indicate that clinical response to antidepressant treatment is associated with COVID-19 history and baseline SARS-CoV-2 antibody levels. Nevertheless, further research in this area is needed to systematize antidepressant treatment in COVID-19 survivors.

Neutrophil to lymphocyte ratio and antidepressant treatment response in patients with major depressive disorder: Effect of sex and hippocampal volume

Several factors may affect response to treatment in Major Depressive Disorder (MDD) including immune/inflammatory alterations and regional brain volumes, particularly in hippocampal regions which have shown to be influenced by inflammatory status. Neutrophil-to-lymphocyte ratio (NLR) is an inflammatory marker found to be elevated in depressed women in large population studies. Here we investigate the effect of NLR on treatment response in MDD patients, and the role of sex and hippocampal volume on influencing this relationship. A sample of 124 MDD depressed inpatients (F = 80) underwent MRI acquisition, admission NLR was calculated by dividing absolute neutrophil by absolute lymphocyte counts and depression severity was assessed at admission and discharge via the Hamilton Depression Rating Scale (HDRS). As a measure of treatment response, delta HDRS was calculated. We found a significant moderation effect of sex on the relationship between NLR and Delta HDRS: a negative relation was found in females and a positive one in males. NLR was found to negatively affect hippocampal volumes in females. Both left and right hippocampal volume positively associated with Delta HDRS. Finally, left hippocampal volume mediated the effect of NLR on Delta HDRS in females. Sex moderated the relation between inflammation and treatment response in line with previous reports linking inflammation to hampered antidepressant effect in females. Further, this effect is partially mediated by hippocampal volume, suggesting that antidepressant response may be hampered by the detrimental effect of inflammation on the brain.

The Patient's Perspective on the Effects of Intranasal Esketamine in Treatment-Resistant Depression

The effectiveness of the esketamine nasal spray (ESK-NS) for treatment-resistant depression (TRD) has been confirmed by real-world studies. Available evidence derived from clinician-rated assessments might differ from patients' perceptions about the helpfulness of treatments. We aimed to verify the effect of ESK-NS from patients' view in 25 TRD patients (56% males, 55.1 ± 10.9 years) treated with ESK-NS (mean dose: 78.4 ± 11.43 mg) for three months and evaluated at different time-points through clinician-rated and self-administered scales, assessing changes in depression, anhedonia, sleep, cognition, suicidality, and anxiety. We observed an overall early improvement that lasted over time (endpoint total score reduction in Montgomery-Åsberg Depression Rating Scale, p < 0.001, Beck Depression Inventory, p = 0.003). Patients reported a significant self-rated decrease in anhedonia at two months (Snaith-Hamilton Pleasure Scale, p = 0.04) and in suicide ideation at endpoint (BDI subitem 9, p = 0.039) vs. earlier improvements detected by clinicians (one-month reduction in MADRS subitem 8, p = 0.005, and subitem 10, p = 0.007). These findings confirm the effectiveness of a three-month treatment with ESK-NS in TRD patients, highlighting an overall overlapping response from patients' and clinicians' perspectives, although with some differential effects on specific symptoms at given time-points. Including patients' viewpoints in routine assessments could inform clinical practice, ensuring a better characterization of clinical phenotypes to deliver personalized interventions.

The 2023 Impact of Inflammatory Bowel Disease in Canada: Mental Health and Inflammatory Bowel Disease

Psychiatric disorders are 1.5 to 2 times more prevalent in persons with inflammatory bowel disease (IBD) than in the general population, with pooled prevalence estimates of 21% for clinical anxiety and 15% for depression. Rates are even higher when considering mental health symptoms, as nearly one-third of persons with IBD experience elevated anxiety symptoms and one-quarter experience depression symptoms. Rates of these symptoms were much higher during periods of disease activity, more common in women than men, and more common in Crohn's disease than ulcerative colitis. There is robust evidence of the detrimental effects of comorbid depression and anxiety on the subsequent course of IBD based on longitudinal studies tracking outcomes over time. However, psychiatric disorders and IBD have bidirectional effects, with each affecting risk of the other. Elevated mental health concerns have been consistently associated with greater healthcare utilization and costs related to IBD. There is some signal that low resilience in adolescence could be a risk factor for developing IBD and that enhancing resilience may improve mental health and intestinal disease outcomes in IBD. Psychological therapies used to treat anxiety and depression occurring in the context of IBD have been shown to significantly improve the quality of life for persons with IBD and reduce anxiety and depression. There is less evidence in regard to the impact of psychotropic medications on mental health or disease outcomes in persons with IBD. There is consensus, however, that mental health must be addressed as part of comprehensive IBD care for children and adults.

Anhedonia and Depressive Disorders

Anhedonia is a core symptom of depression and of several psychiatric disorders. Anhedonia has however expanded from its original definition to encompass a spectrum of reward processing deficits that received much interest in the last decades. It is a relevant risk factor for possible suicidal behaviors, and that it may operate as an independent risk factor for suicidality apart from the episode severity. Anhedonia has also been linked to inflammation with a possible reciprocal deleterious effect on depression. Its neurophysiological bases mainly include alterations in striatal and prefrontal areas, with dopamine being the most involved neurotransmitter. Anhedonia is thought to have a significant genetic component and polygenic risk scores are a possible tool for predicting an individual's risk for developing anhedonia. Traditional antidepressants, such as selective serotonin reuptake inhibitors, showed a limited benefit on anhedonia, also considering their potential pro-anhedonic effect in some subjects. Other treatments may be more effective in treating anhedonia, such as agomelatine, vortioxetine, ketamine and transcranial magnetic stimulation. Psychotherapy is also widely supported, with cognitive-behavioral therapy and behavioral activation both showing benefit. In conclusion, a large body of evidence suggests that anhedonia is, at least partially, independent from depression, therefore it needs careful assessment and targeted treatment.

Fight the Fire: Association of Cytokine Genomic Markers and Suicidal Behavior May Pave the Way for Future Therapies

The fight against suicide is highly challenging as it may be one of the most complex and, at the same time, most threatening among all psychiatric phenomena. In spite of its huge impact, and despite advances in neurobiology research, understanding and predicting suicide remains a major challenge for both researchers and clinicians. To be able to identify those patients who are likely to engage in suicidal behaviors and identify suicide risk in a reliable and timely manner, we need more specific, novel biological and genetic markers/indicators to develop better screening and diagnostic methods, and in the next step to utilize these molecules as intervention targets. One such potential novel approach is offered by our increasing understanding of the involvement of neuroinflammation based on multiple observations of increased proinflammatory states underlying various psychiatric disorders, including suicidal behavior. The present paper overviews our existing understanding of the association between suicide and inflammation, including peripheral and central biomarkers, genetic and genomic markers, and our current knowledge of intervention in suicide risk using treatments influencing inflammation; also overviewing the next steps to be taken and obstacles to be overcome before we can utilize cytokines in the treatment of suicidal behavior.

Unhealthy lifestyle impacts on biological systems involved in stress response: hypothalamic-pituitary-adrenal axis, inflammation and autonomous nervous system

An unhealthy lifestyle has a critical role in the pathogenesis and course of several chronic disorders. It has been hypothesized that lifestyle may also impact biological systems involved in stress response. A global index of unhealthy lifestyle was calculated based on the cumulative presence of five self-reported lifestyle habits (smoking, excessive alcohol use, drug use, low physical activity and short sleep) in 2783 participants (18-65 years) from the Netherlands Study of Depression and Anxiety. The functioning of biological stress systems was based on multiple physiological measures of cortisol, inflammatory cytokines and autonomic cardiac activity. The unhealthy lifestyle index was associated with hyperactivity of hypothalamus-pituitary-adrenal axis and increased inflammation, indicating that with increasing unhealthy habits, the level of biological stress increases. No association with the autonomic nervous system activity was observed; however, the use of drugs increased parasympathetic cardiac activity and significantly impacted on ANS. Results were not impacted by a recent episode of depression or anxiety disorder. An unhealthy lifestyle may unfavorably impact on biological systems involved in stress response, which may underlie progression of several psychiatric as well as somatic chronic disorders.

Clinical Utility of Fluid Biomarker in Depressive Disorder

Major depressive disorders are ranked as the single largest contributor to non-fatal health loss and biomarkers could largely improve our routine clinical activity by predicting disease course and guiding treatment. However there is still a dearth of valid biomarkers in the field of psychiatry. The initial assumption that a single biomarker can capture the myriad of complex processes proved to be naive. The purpose of this paper is to critically review the field and to illustrate the possible practical application for routine clinical care. Biomarkers derived from DNA analysis are the ones that have received the most attention. Other potential candidates include circulating transcription products, proteins, and inflammatory markers. DNA polygenic risk scores proved to be useful in other fields of medicine and preliminary results suggest that they could be useful both as risk and diagnostic biomarkers also in depression and for the choice of treatment. A number of other possible fluid biomarkers are currently under investigation for diagnosis, outcome prediction, staging, and stratification of interventions, however research is still needed before they can be used for routine clinical care. When available, clinicians may be able to receive a lab report with detailed information about disease risk, outcome prediction, and specific indications about preferred treatments.

Biology of cyclooxygenase-2: An application in depression therapeutics

Depressive Disorder is a common mood disorder or affective disorder that is dominated by depressed mood. It is characterized by a high incidence and recurrence. The onset of depression is related to genetic, biological and psychosocial factors. However, the pathogenesis is still unclear. In recent years, there has been an increasing amount of research on the inflammatory hypothesis of depression, in which cyclo-oxygen-ase 2 (COX-2), a pro-inflammatory cytokine, is closely associated with depression. A variety of chemical drugs and natural products have been found to exert therapeutic effects by modulating COX-2 levels. This paper summarizes the relationship between COX-2 and depression in terms of neuroinflammation, intestinal flora, neurotransmitters, HPA axis, mitochondrial dysfunction and hippocampal neuronal damage, which can provide a reference for further preventive control, clinical treatment and scientific research on depression.

Post-COVID-19 Depressive Symptoms: Epidemiology, Pathophysiology, and Pharmacological Treatment

The Coronavirus Disease 2019 (COVID-19) pandemic is still spreading worldwide over 2 years since its outbreak. The psychopathological implications in COVID-19 survivors such as depression, anxiety, and cognitive impairments are now recognized as primary symptoms of the "post-acute COVID-19 syndrome." Depressive psychopathology was reported in around 35% of patients at short, medium, and long-term follow-up after the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection. Post-COVID-19 depressive symptoms are known to increase fatigue and affect neurocognitive functioning, sleep, quality of life, and global functioning in COVID-19 survivors. The psychopathological mechanisms underlying post-COVID-19 depressive symptoms are mainly related to the inflammation triggered by the peripheral immune-inflammatory response to the viral infection and to the persistent psychological burden during and after infection. The large number of SARS-CoV-2-infected patients and the high prevalence of post-COVID-19 depressive symptoms may significantly increase the pool of people suffering from depressive disorders. Therefore, it is essential to screen, diagnose, treat, and monitor COVID-19 survivors' psychopathology to counteract the depression disease burden and related years of life lived with disability. This paper reviews the current literature in order to synthesize the available evidence regarding epidemiology, clinical features, neurobiological underpinning, and pharmacological treatment of post-COVID-19 depressive symptoms.