Disgust affects TNF-alpha, IL-6 and noradrenalin levels in patients with obsessive-compulsive disorder

Large nesting expression in deer mice remains stable under conditions of visual deprivation despite heightened limbic involvement: Perspectives on compulsive-like behavior

Visual stimuli and limbic activation varyingly influence obsessive-compulsive symptom expression and so impact treatment outcomes. Some symptom phenotypes, for example, covert repugnant thoughts, are likely less sensitive to sensory stimuli compared to symptoms with an extrinsic focus, that is, symptoms related to contamination, safety, and "just-right-perceptions." Toward an improved understanding of the neurocognitive underpinnings of obsessive-compulsive psychobiology, work in naturalistic animal model systems is useful. Here, we explored the impact of visual feedback and limbic processes on 24 normal (NNB) and large (LNB) nesting deer mice, respectively (as far as possible, equally distributed between sexes). Briefly, after behavioral classification into either the NNB or LNB cohorts, mice of each cohort were separated into two groups each and assessed for nesting expression under either standard light conditions or conditions of complete visual deprivation (VD). Nesting outcomes were assessed in terms of size and neatness. After nesting assessment completion, mice were euthanized, and samples of frontal-cortical and hippocampal tissues were collected to determine serotonin and noradrenaline concentrations. Our results show that LNB, as opposed to NNB, represents an inflexible and excessive behavioral phenotype that is not dependent on visually guided action-outcome processing, and that it associates with increased frontal-cortical and hippocampal noradrenaline concentrations, irrespective of lighting condition. Collectively, the current results are informing of the neurocognitive underpinnings of nesting behavior. It also provides a valuable foundation for continued investigations into the noradrenergic mechanisms that may influence the development and promulgation of excessive, rigid, and inflexible behaviors.

Sex-dependent association of DNA methylation of HPA axis-related gene FKBP5 with obsessive-compulsive disorder

AIMS

Although hypothalamic-pituitary-adrenal (HPA) axis dysregulation in obsessive-compulsive disorder (OCD) has been reported, epigenetic changes in HPA axis-related genes have not been well studied in OCD. The present study investigated whether the epigenetic regulation of FK506-binding protein 51 gene (FKBP5) intron 7 is associated with OCD status in each sex. In addition, relationships among the DNA methylation levels of FKBP5 intron 7, OCD status and early-life trauma were explored.

METHODS

A total of 267 patients with OCD and 201 controls aged between 18 and 40 years were recruited. Demographic and clinical assessment, FKBP5 rs1360780 genotyping, and pyrosequencing of FKBP5 intron 7 were conducted. DNA was extracted from peripheral blood leucocytes. First, multivariate analysis of covariance for differential DNA methylation levels between OCD patients and controls was conducted with adjustment for FKBP5 rs1360780 genotype, early-life trauma, depressive symptoms, and age as covariates in each sex. Next, path analysis was conducted to determine the mediation effects of DNA methylation levels of FKBP5 between early-life trauma and OCD status. In addition, sensitivity analyses for medication and lifetime major depression were also performed.

RESULTS

DNA methylation at the FKBP5 intron 7 CpG site was significantly lower in men with OCD, compared to controls (mean difference -1.33%, 95% CI -2.11 to -0.55, p < 0.001). The results remained significant for drug naïve or free subjects (mean difference -1.27%, 95% CI -2.18 to -0.37, p = 0.006, in men) and for subjects without lifetime major depressive disorder (mean difference -1.60%, 95% CI -2.54 to -0.66, p < 0.001, in men). The mediation effect of DNA methylation levels was not significant between early-life trauma and OCD status.

CONCLUSION

These findings suggest that epigenetic factors of HPA axis-related gene FKBP5 may play a role in the pathogenesis of OCD. Further studies are needed to determine how altered DNA methylation of FKBP5 intron 7 and HPA axis function are involved in OCD.

Implication of microbiota gut-brain axis in the manifestation of obsessive-compulsive disorder: Preclinical and clinical evidence

Recent research has highlighted the key role of gut microbiota in the development of psychiatric disorders. The adverse impact of stress, anxiety, and depression has been well documented on the commensal gut microflora. Thus, therapeutic benefits of gut microbiota-based interventions may not be avoided in central nervous system (CNS) disorders. In this review, we outline the current state of knowledge of gut microbiota with respect to obsessive-compulsive disorder (OCD). We discuss how OCD-generated changes corresponding to the key neurotransmitters, hypothalamic-pituitary-adrenal axis, and immunological and inflammatory pathways are connected with the modifications of the microbiota-gut-brain axis. Notably, administration of few probiotics such as Lactobacillus rhamnosus (ATCC 53103), Lactobacillus helveticus R0052, Bifidobacterium longum R0175, Saccharomyces boulardii, and Lactobacillus casei Shirota imparted positive effects in the management of OCD symptoms. Taken together, we suggest that the gut microbiota-directed therapeutics may open new treatment approaches for the management of OCD.

Socioemotional deficit and HPA axis time response in high compulsive rats selected by schedule-induced polydipsia

Compulsivity is a failure to stop an ongoing behavior that has become inappropriate to the situation and is recognized as a transdiagnostic trait present in different neuropsychiatric disorders. The implication of motivation and emotion, as well as the stress response in compulsive population has not been fully understood. We assessed the motivation to reward and cues, the emotional response in different contexts and the hypothalamic-pituitary-adrenal (HPA) axis response in rats selected by a preclinical model of compulsive behavior. Firstly, high (HD) or low (LD) drinkers were selected according to their drinking behavior on schedule-induced polydipsia (SIP). Then, we assessed motivation by the propensity to attribute incentive salience to rewards on Pavlovian Conditioned Approach (PavCA) and motivation to gain reward on Progressive Ratio Schedule of Reinforcement (PRSR). Emotion was measured by Social Dominance on the Tube Test (SDTT) and emotional memory on Passive Avoidance (PA). Plasma corticosterone (CORT) levels in response to SIP were assessed. HD rats showed a socioemotional deficit by fewer victories on the SDTT, and an increased latency to enter the dark compartment on the PA. No differences were found between groups regarding to motivational assessment. Moreover, HD rats revealed a blunted time response in the increase of CORT levels at 45 min after SIP compared to LD rats. The findings show that the compulsive phenotype of HD rats exhibit less social dominance, more resistance to extinction and a differential CORT time response to SIP. These findings may contribute to highlight the relevance of assessing socioemotional behaviors and stress response for a better characterization of the vulnerability to compulsive spectrum disorders.

The Nrf2 pathway in psychiatric disorders: pathophysiological role and potential targeting

Introduction: All psychiatric disorders exhibit excitotoxicity, mitochondrial dysfunction, inflammation, oxidative stress, and neural damage as their common characteristic. The endogenous nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway is implicated in the defense mechanism against oxidative stress and has a significant role in psychiatric disorders.Areas covered: We explore the role of Nrf2 pathway and its modulators in psychiatric disorders. The literature was searched utilizing various databases such as Embase, Medline, Web of Science, Pub-Med, and Google Scholar from 2010 to 2020. The search included research articles, clinical reports, systematic reviews, and meta-analyses.Expert opinion: Environmental factors and genetic predisposition can be a trigger for the development of psychiatric disorders. Nrf2 downregulates certain inflammatory pathways and upregulates various antioxidant enzymes to maintain a balance. However, its intricate balance with NF-Kβ (Nuclear factor kappa light chain enhancer of activated B cells) and its crosstalk with the transcription factor Nrf2 is critical in severe oxidative stress. Several Nrf2 modulators are now in clinical trials and can help reduce oxidative stress and neuroinflammation. There are immense potential opportunities for these modulators to become a novel therapeutic option.

Low hair cortisol concentrations in obsessive compulsive disorder: A cross-sectional study

Recent findings have highlighted the association between changes in the activity of the HPA axis, primarily its end-hormone, cortisol and OCD. However, to date, cortisol levels of OCD patients have been assessed mainly in body fluids, such as serum, saliva or urine, frequently leading to ambiguous results because of their inherent lack of stability. The aim of this study was to investigate time-integrated levels of stress exposure in 32 OCD patients and 32 sex and age-matched healthy controls by measuring endogenous cortisol in hair segments reflecting the last 3 months preceding hair collection. Psychometric parameters, including BDI, FQ, STAI, PSS and ECQ-R, were obtained in all participants; Y-BOCS was performed in the OCD patients. The OCD patients exhibited significantly higher scores in all psychometric instruments administered and lower hair cortisol concentrations than the healthy controls (p = 0.001, r = 0.41). No significant correlations were found between the HCC and the Y-BOCS total scores. After having sorted OCD patients into subtypes, according to the nature of their symptomatology, the "washers/cleaners" category showed the lowest HCC (compared to the "checking/harming", "ordering/symmetry" and "sexual/religious obsessions" categories). The novel finding of chronic low cortisol secretion in OCD patients could be attributed to a possible down-regulation of the HPA axis, as an adaptive response to chronic stress exposure. Given that the OCD subtypes reflect the great heterogeneity in the OCD spectrum, studies with larger samples should extend the investigation of HCC in patients with distinctive symptomatology, so as to develop a basis for better neuroendocrine profiling and understanding of the pathophysiology of OCD. Further work is needed in exploring HPA axis' activity over the natural course and treatments of the disorder.

Multi-level assessment of obsessive-compulsive disorder (OCD) reveals relations between neural and neurochemical levels

BACKGROUND

While considerable progress has been made in exploring the psychological, the neural, and the neurochemical dimensions of OCD separately, their interplay is still an open question, especially their changes during psychotherapy.

METHODS

Seventeen patients were assessed at these three levels by psychological questionnaires, fMRI, and venipuncture before and after inpatient psychotherapy. Seventeen controls were scanned at comparable time intervals. First, pre/post treatment changes were investigated for all three levels separately: symptom severity, whole-brain and regional activity, and the concentrations of cortisol, serotonin, dopamine, brain-derived neurotrophic factor (BDNF), and immunological parameters (IL-6, IL-10, TNFα). Second, stepwise linear modeling was used to find relations between the variables of the levels.

RESULTS

The obsessive-compulsive, depressive, and overall symptom severity was significantly reduced after psychotherapy. At the neural level, the activity in the anterior cingulate cortex (ACC), in frontal regions, in the precuneus, and in the putamen had significantly decreased. No significant changes were found on the neurochemical level. When connecting the levels, a highly significant model was found that explains the decrease in neural activity of the putamen by increases of the concentrations of cortisol, IL-6, and dopamine.

CONCLUSION

Multivariate approaches offer insight on the influences that the different levels of the psychiatric disorder OCD have on each other. More research and adapted models are needed.

The Psychopharmacology of Obsessive-Compulsive Disorder: A Preclinical Roadmap

This review evaluates current knowledge about obsessive-compulsive disorder (OCD), with the goal of providing a roadmap for future directions in research on the psychopharmacology of the disorder. It first addresses issues in the description and diagnosis of OCD, including the structure, measurement, and appropriate description of the disorder and issues of differential diagnosis. Current pharmacotherapies for OCD are then reviewed, including monotherapy with serotonin reuptake inhibitors and augmentation with antipsychotic medication and with psychologic treatment. Neuromodulatory therapies for OCD are also described, including psychosurgery, deep brain stimulation, and noninvasive brain stimulation. Psychotherapies for OCD are then reviewed, focusing on behavior therapy, including exposure and response prevention and cognitive therapy, and the efficacy of these interventions is discussed, touching on issues such as the timing of sessions, the adjunctive role of pharmacotherapy, and the underlying mechanisms. Next, current research on the neurobiology of OCD is examined, including work probing the role of various neurotransmitters and other endogenous processes and etiology as clues to the neurobiological fault that may underlie OCD. A new perspective on preclinical research is advanced, using the Research Domain Criteria to propose an adaptationist viewpoint that regards OCD as the dysfunction of a normal motivational system. A systems-design approach introduces the security motivation system (SMS) theory of OCD as a framework for research. Finally, a new perspective on psychopharmacological research for OCD is advanced, exploring three approaches: boosting infrastructure facilities of the brain, facilitating psychotherapeutic relearning, and targeting specific pathways of the SMS network to fix deficient SMS shut-down processes. SIGNIFICANCE STATEMENT: A significant proportion of patients with obsessive-compulsive disorder (OCD) do not achieve remission with current treatments, indicating the need for innovations in psychopharmacology for the disorder. OCD may be conceptualized as the dysfunction of a normal, special motivation system that evolved to manage the prospect of potential danger. This perspective, together with a wide-ranging review of the literature, suggests novel directions for psychopharmacological research, including boosting support systems of the brain, facilitating relearning that occurs in psychotherapy, and targeting specific pathways in the brain that provide deficient stopping processes in OCD.

Cortisol, DHEA and DHEA-S during exposure therapy in patients with obsessive-compulsive disorder - secretion patterns and prediction of treatment response

The cortisol response in patients with obsessive-compulsive disorder (OCD) during exposure with response prevention (ERP), a stressful but very effective psychotherapeutic treatment, has shown contradictory findings in three prior studies with low sample sizes. In a larger cohort of 51 patients with OCD we repeatedly measured subjective units of distress (SUD) and the adrenocortical stress hormones cortisol, dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEA-S) in saliva during the very first session of ERP and on the day before. Expectedly, SUD were increased on the ERP day before the session and further rose during ERP, but salivary cortisol and DHEA were statistically indistinguishable from the comparison condition. Interestingly, DHEA-S was significantly elevated throughout the ERP versus the comparison day, but did not further increase in acute response to ERP. According to an explorative analysis in a subsample, hormone levels on the comparison or the ERP day did not predict anti-OCD treatment response one month later. These results corroborate our prior findings of cortisol non-response despite considerable subjective stress in ERP. The role of DHEA-S in anticipatory anxiety and the effects of augmentative cortisol therapy in ERP need further study.

Relationship between obsessive compulsive disorder and cortisol: Systematic review and meta-analysis

Altered stress response and consequent elevated levels of circulating glucocorticoids have been found in neuropsychiatric disorders such as depression or anxiety disorders and proposed to also play a role in the pathophysiology of obsessive-compulsive disorder (OCD). Despite the observation that stressful events may precede the disease onset or even exacerbate its symptoms, studies in this field do not always report consistent results regarding the cortisol profile of OCD patients. As such, a systematic review and meta-analysis was developed to clarify this issue. This systematic review and meta-analysis was elaborated according to the PRISMA method. The analytical procedures were implemented using Metafor package in R software. Nineteen studies were included in the systematic review and 18 were included in the meta-analysis. The meta-analytic results demonstrated that OCD patients had significantly higher cortisol levels compared to controls (d = 0.76, SE = 0.146, p < 0.001). For studies using the average of multiple assessments, the standardized coefficient was significantly higher when compared to studies focusing on single measurements. Both the systematic review and meta-analysis suggest that cortisol levels are significantly higher in OCD patients than healthy individuals.

Immune Aberrations in Obsessive-Compulsive Disorder: a Systematic Review and Meta-analysis

Some lines of evidence have indicated that immune dysregulation could play a role in the pathophysiology of obsessive-compulsive disorder (OCD). However, results have been inconsistent across studies. Thus, a systematic review and meta-analysis of studies measuring immune mediators in participants with OCD compared to healthy controls (HC) was conducted. The PubMed/MEDLINE, PsycINFO, and EMBASE electronic databases were systematically searched from inception through June 21, 2018. Sixteen studies met inclusion criteria comprising data from 1001 participants (538 with OCD and 463 were HCs). Levels of TNF-α, IL-6, IL-1β, IL-4, IL-10, and interferon-γ did not significantly differ between participants with OCD and healthy controls. In addition, the ex vivo production of TNF-α and IL-6 by isolated macrophages did not significantly differ between participants with OCD and HCs. Nevertheless, included studies have varied in methodological quality with the enrollment of samples that differed regarding medication status, the proper matching of OCD participants and HCs, age groups, and the presence of psychiatric comorbidities. In conclusion, an association between immune dysregulation and OCD remains unproven. Future studies should consider enrolling larger and more homogeneous samples with OCD.

Individualized Immunological Data for Precise Classification of OCD Patients

Obsessive⁻compulsive disorder (OCD) affects about 2% of the general population, for which several etiological factors were identified. Important among these is immunological dysfunction. This review aims to show how immunology can inform specific etiological factors, and how distinguishing between these etiologies is important from a personalized treatment perspective. We found discrepancies concerning cytokines, raising the hypothesis of specific immunological etiological factors. Antibody studies support the existence of a potential autoimmune etiological factor. Infections may also provoke OCD symptoms, and therefore, could be considered as specific etiological factors with specific immunological impairments. Finally, we underline the importance of distinguishing between different etiological factors since some specific treatments already exist in the context of immunological factors for the improvement of classic treatments.

Immune system and obsessive-compulsive disorder

BACKGROUND

Recently, much attention has been devoted to the possible alterations of the immune system in obsessive-compulsive disorder (OCD). Therefore, the aim of this paper was to review the current literature on the relationships between OCD and immune system.

METHODS

A PubMed and Google Scholar search was performed with specific keywords.

RESULTS

In the childhood, much emphasis has been given to the relationship between group A Streptococcus (GAS) infection and the development of a group of clinical syndromes characterized by neuropsychiatric symptoms known as "pediatric autoimmune neuropsychiatric disorders associated with streptococcus" (PANDAS). However, more recently, PANDAS has been reconsidered and evolved towards pediatric acute-onset neuropsychiatric syndrome (PANS) and/or Childhood Acute Neuropsychiatric Syndrome (CANS) all characterized by the presence of typical of OCD symptoms and tics. In adult OCD patients, different immunological parameters have been described to differ from those of healthy control subjects, although a few numbers of studies were carred out and most of them performed in small samples.

CONCLUSIONS

Although the exact relationships between OCD and immune processes are still unclear, available literature supports their role in the pathophysiology of OCD, while providing a fascinating hint for possible immunotherapeutic treatments in OCD.

Inflammatory dysregulation of monocytes in pediatric patients with obsessive-compulsive disorder

BACKGROUND

Although the exact etiology of obsessive-compulsive disorder (OCD) is unknown, there is growing evidence of a role for immune dysregulation in the pathophysiology of the disease, especially in the innate immune system including the microglia. To test this hypothesis, we studied inflammatory markers in monocytes from pediatric patients with OCD and from healthy controls.

METHODS

We determined the percentages of total monocytes, CD16+ monocytes, and classical (CD14^highCD16-), intermediate (CD14^highCD16^low), and non-classical (CD14^lowCD16^high) monocyte subsets in 102 patients with early-onset OCD and in 47 healthy controls. Moreover, proinflammatory cytokine production (GM-CSF, IL-1β, IL-6, IL-8, and TNF-α) was measured by multiplex Luminex analysis in isolated monocyte cultures, in basal conditions, after exposure to lipopolysaccharide (LPS) to stimulate immune response or after exposure to LPS and the immunosuppressant dexamethasone.

RESULTS

OCD patients had significantly higher percentages of total monocytes and CD16+ monocytes than healthy controls, mainly due to an increase in the intermediate subset but also in the non-classical monocytes. Monocytes from OCD patients released higher amounts of GM-CSF, IL-1β, IL-6, IL-8, and TNF-α than healthy controls after exposure to LPS. However, there were no significant differences in basal cytokine production or the sensitivity of monocytes to dexamethasone treatment between both groups. Based on monocyte subset distribution and cytokine production after LPS stimulation, patients receiving psychoactive medications seem to have an intermediate inflammatory profile, that is, lower than non-medicated OCD individuals and higher than healthy controls.

CONCLUSIONS

These results strongly support the involvement of an enhanced proinflammatory innate immune response in the etiopathogenesis of early-onset OCD.

Biological markers for anxiety disorders, OCD and PTSD: A consensus statement. Part II: Neurochemistry, neurophysiology and neurocognition

OBJECTIVE

Biomarkers are defined as anatomical, biochemical or physiological traits that are specific to certain disorders or syndromes. The objective of this paper is to summarise the current knowledge of biomarkers for anxiety disorders, obsessive-compulsive disorder (OCD) and posttraumatic stress disorder (PTSD).

METHODS

Findings in biomarker research were reviewed by a task force of international experts in the field, consisting of members of the World Federation of Societies for Biological Psychiatry Task Force on Biological Markers and of the European College of Neuropsychopharmacology Anxiety Disorders Research Network.

RESULTS

The present article (Part II) summarises findings on potential biomarkers in neurochemistry (neurotransmitters such as serotonin, norepinephrine, dopamine or GABA, neuropeptides such as cholecystokinin, neurokinins, atrial natriuretic peptide, or oxytocin, the HPA axis, neurotrophic factors such as NGF and BDNF, immunology and CO2 hypersensitivity), neurophysiology (EEG, heart rate variability) and neurocognition. The accompanying paper (Part I) focuses on neuroimaging and genetics.

CONCLUSIONS

Although at present, none of the putative biomarkers is sufficient and specific as a diagnostic tool, an abundance of high quality research has accumulated that should improve our understanding of the neurobiological causes of anxiety disorders, OCD and PTSD.

Plasma cytokine abnormalities in drug-naïve, comorbidity-free obsessive-compulsive disorder

Growing evidence in the last decade suggest significant role of immune alterations in the pathogenesis of obsessive-compulsive disorder (OCD). Cytokines, mediators of inflammation, alter the neurotransmitter concentration and result in a hyposerotonergic and hyperglutamatergic state implicated in pathogenesis of OCD. However, only few studies have examined cytokine abnormalities in OCD with inconsistent results possibly due to confounding effects of medications and comorbid anxiety-depression. We examined 20 comorbidity free, drug free OCD patients and 20 age and sex matched healthy controls. Clinical severity was assessed using Yale Brown Obsessive Compulsive Scale, Hamilton anxiety rating scale, Hamilton depression rating scale and Clinical Global Impression. Levels of different cytokines, Interleukin (IL)-2, IL-4, IL-6, IL-10, Tumor necrosis factor (TNF)-α and Interferon (IFN)-γ were assessed using Cytometric Bead Array. OCD patients had significantly greater plasma levels of IL-2, IL-4, IL-6, IL-10 and TNF-α levels than controls but not IFN-γ. Reanalysis of data with only drug naïve patients (excluding 4 drug free patients) did not alter the results. Presence of these abnormalities in drug-naïve patients suggests the possible role of cytokines in the pathogenesis of OCD. Study findings have potential clinical utility in development of novel therapeutic options targeting cytokine aberrations in OCD.

Neuroinflammatory pathways in anxiety, posttraumatic stress, and obsessive compulsive disorders

As prevalence of anxiety, posttraumatic stress, and obsessive compulsive disorders continue to rise worldwide, increasing focus has been placed on immune mediated theories in understanding the underlying mechanisms of these disorders. Associations between the dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and these disorders have been recognized in the scientific literature, specifically in regard to cortisol levels, as well as changes in pro- and anti-inflammatory cytokines. The present commentary will systematically assess the scientific literature within the past decade in regard to the psychoneuroimmunology of anxiety, posttraumatic stress, and obsessive compulsive disorders. Understanding the mechanisms of these disorders is essential in order to determine efficacious and targeted treatment strategies, which may lead to substantial improvements in overall functioning, as well as significant decreases in societal and economic burden.

Effective behavioural strategies for reducing disgust in contamination-related OCD: A review

Disgust is an understudied but important emotion in various psychological disorders. Over the last decade, increasing evidence suggests that disgust is also present in various subtypes of obsessive-compulsive disorder (OCD), especially in contamination-related OCD (C-OCD). The treatment of choice for C-OCD is exposure with response prevention, originally designed to reduce fear-associated emotions thought to be acquired through Pavlovian conditioning (PC). However, disgust has been proposed to be acquired through evaluative conditioning (EC) and according to the referential model of this form of learning, there are functional differences between PC and EC that need to be considered in the treatment of disgust-related responses. Alternative strategies suggested by EC-based models include counterconditioning (contingent presentation of the CS with a US of opposite valence) and US revaluation (contingent presentation of the US with US of opposite valence). Drawing on the referential model, this paper reviews evidence for the effectiveness of each strategy to identify the most theoretically sound and empirically valid intervention to reduce disgust in C-OCD.

Anti-basal ganglia antibodies in primary obsessive-compulsive disorder: systematic review and meta-analysis

BACKGROUND

Autoimmune-mediated basal ganglia dysfunction is implicated in the pathophysiology of neuropsychiatric disorders commonly manifesting with obsessive-compulsive features (e.g. Sydenham chorea). The relationship between autoimmunity and primary obsessive-compulsive disorder (OCD), however, is less clear.

AIMS

To pool data on serum and cerebrospinal fluid (CSF) anti-basal ganglia antibody (ABGA) positivity in primary OCD (without neurological or autoimmune comorbidity) relative to controls or neuropsychiatric disorders previously associated with increased odds of ABGA positivity.

METHOD

We performed electronic database and hand-searches for studies meeting pre-specified eligibility criteria from which we extracted data using a standardised form. We calculated pooled estimates of ABGA positivity using a random-effects model.

RESULTS

Seven case-control studies totalling 844 participants met the eligibility criteria. Meta-analysis showed that a significantly greater proportion of those with primary OCD were ABGA seropositive compared with various controls (odds ratio (OR) = 4.97, 95% CI 2.88-8.55, P<0.00001). This effect was not associated with heterogeneity or publication bias, and remained significant after stratifying the analysis by age, gender, disease severity, illness duration, immunostaining methodology, study quality, publication type, kind of control group, and sample size. There were no significant differences in ABGA seropositivity for comparisons between primary OCD and Tourette syndrome, attention-deficit hyperactivity disorder or paediatric acute-onset neuropsychiatric syndrome.

RESULTS

of one study testing CSF samples showed that a significantly greater proportion of participants with primary OCD were ABGA CSF-positive compared with healthy controls (OR = 5.60, 95% CI 1.04-30.20, P = 0.045).

CONCLUSIONS

Odds of ABGA seropositivity are increased fivefold in primary OCD compared with controls, but are comparable to those associated with disorders previously associated with ABGA, providing circumstantial evidence of autoimmunity in a subset of those with primary OCD. Further experimental studies are needed to ascertain whether this relationship is causal.

Deep brain stimulation for obsessive-compulsive disorder is associated with cortisol changes

Deep brain stimulation (DBS) is an effective treatment for obsessive-compulsive disorder (OCD), but its mechanism of action is largely unknown. Since DBS may induce rapid symptomatic changes and the pathophysiology of OCD has been linked to the hypothalamic-pituitary-adrenal (HPA) axis, we set out to study whether DBS affects the HPA axis in OCD patients. We compared a stimulation ON and OFF condition with a one-week interval in 16 therapy-refractory OCD patients, treated with DBS for at least one year, targeted at the nucleus accumbens (NAc). We measured changes in 24-h urinary excretion of free cortisol (UFC), adrenaline and noradrenaline and changes in obsessive-compulsive (Y-BOCS), depressive (HAM-D) and anxiety (HAM-A) symptom scores. Median UFC levels increased with 53% in the OFF condition (from 93 to 143nmol/24h, p=0.12). There were no changes in urinary adrenaline or noradrenaline excretion. The increase in Y-BOCS (39%), and HAM-D (78%) scores correlated strongly with increased UFC levels in the OFF condition. Our findings indicate that symptom changes following DBS for OCD patients are associated with changes in UFC levels.

Neuroinflammation and psychiatric illness

Multiple lines of evidence support the pathogenic role of neuroinflammation in psychiatric illness. While systemic autoimmune diseases are well-documented causes of neuropsychiatric disorders, synaptic autoimmune encephalitides with psychotic symptoms often go under-recognized. Parallel to the link between psychiatric symptoms and autoimmunity in autoimmune diseases, neuroimmunological abnormalities occur in classical psychiatric disorders (for example, major depressive, bipolar, schizophrenia, and obsessive-compulsive disorders). Investigations into the pathophysiology of these conditions traditionally stressed dysregulation of the glutamatergic and monoaminergic systems, but the mechanisms causing these neurotransmitter abnormalities remained elusive. We review the link between autoimmunity and neuropsychiatric disorders, and the human and experimental evidence supporting the pathogenic role of neuroinflammation in selected classical psychiatric disorders. Understanding how psychosocial, genetic, immunological and neurotransmitter systems interact can reveal pathogenic clues and help target new preventive and symptomatic therapies.

Non-response of cortisol during stressful exposure therapy in patients with obsessive-compulsive disorder--preliminary results

Exposure with response prevention (ERP) is an established treatment for patients with obsessive-compulsive disorder (OCD) and also an interesting model to characterize neuroendocrine response to psychological stress. However, so far few studies have assessed hypothalamic-pituitary-adrenocortical (HPA) function during ERP and results are inconsistent. In 15 patients with OCD we repeatedly measured salivary cortisol and subjective units of distress (SUD) on two consecutive afternoons. The first day served as a comparison condition; on the second day the very first session of ERP took place. While SUD were significantly increased during ERP versus the comparison day, salivary cortisol was statistically indistinguishable between ERP and comparison conditions before, during and after ERP. Thus, despite considerable psychological stress no increase of cortisol was observed. This response pattern to ERP in OCD patients needs further research.

A cytokine study of adult patients with obsessive-compulsive disorder

OBJECTIVES

We aimed to determine the plasma levels of cytokines in patients with obsessive-compulsive disorder (OCD) as compared with healthy controls and to investigate whether there is any association between their concentrations and OCD clinical and therapeutic features.

METHODS

Forty patients with OCD and 40 healthy controls had their plasmas assessed for a range of cytokines (tumor necrosis factor-α, or TNF-α), chemokines (CCL2, CCL3, CCL11, CCL24, CXCL8, CXCL9, CXCL10), and other mediators (TNF soluble receptors sTNFR1 and sTNFR2 and interleukin-1 receptor antagonist) by enzyme-linked immunosorbent assay. Patients with OCD were further examined with the Mini-International Neuropsychiatric Interview, the Obsessive-Compulsive Inventory-Revised, and the Beck Depression Inventory.

RESULTS

Compared with healthy controls, patients with OCD exhibited significantly increased plasma levels of CCL3, CXCL8, sTNFR1, and sTNFR2. Among patients with OCD, there was a positive correlation between relative antidepressant dose and sTNFr2 levels. Furthermore, although the levels of sTNFR1 correlated positively with the severity of washing symptoms, CCL24 levels correlated negatively with the severity of hoarding.

CONCLUSIONS

The levels of certain immune markers are increased in adult patients with OCD and seem to vary according to predominant symptoms dimensions. Other studies are required to establish whether our findings truly reflect immunologic dysfunction in OCD or are the result of other hidden confounding factors.

Systematic review of proinflammatory cytokines in obsessive-compulsive disorder

Several studies have examined levels of proinflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6. This meta-analysis was conducted to examine the association between obsessive-compulsive disorder (OCD) and plasma serum levels of proinflammatory cytokines. Twelve studies met inclusion criteria. The meta-analysis demonstrated a significant reduction in IL-1β levels in OCD. No significant difference in plasma levels of IL-6 or TNF-α was demonstrated. Stratified subgroup analysis revealed possible moderating effects of age and medication use on IL-6 levels. Studies including children on psychotropic medication had lower plasma IL-6 levels. Stratified subgroup analysis revealed a moderating effect of comorbid depression on TNF-α levels. Elevated TNF-α levels were reported in studies that included individuals with comorbid depression. Future studies examining immune function in OCD should adjust for potential confounding due to medication use and comorbid depression. Further studies assessing cerebrospinal fluid cytokine levels in OCD are also needed.

Disgust: the disease-avoidance emotion and its dysfunctions

This review analyses the accumulating evidence from psychological, psychophysiological, neurobiological and cognitive studies suggesting that the disease-avoidance emotion of disgust is a predominant emotion experienced in a number of psychopathologies. Current evidence suggests that disgust is significantly related to small animal phobias (particularly spider phobia), blood-injection-injury phobia and obsessive-compulsive disorder contamination fears, and these are all disorders that have primary disgust elicitors as a significant component of their psychopathology. Disgust propensity and sensitivity are also significantly associated with measures of a number of other psychopathologies, including eating disorders, sexual dysfunctions, hypochondriasis, height phobia, claustrophobia, separation anxiety, agoraphobia and symptoms of schizophrenia--even though many of these psychopathologies do not share the disease-avoidance functionality that characterizes disgust. There is accumulating evidence that disgust does represent an important vulnerability factor for many of these psychopathologies, but when disgust-relevant psychopathologies do meet the criteria required for clinical diagnosis, they are characterized by significant levels of both disgust and fear/anxiety. Finally, it has been argued that disgust may also facilitate anxiety and distress across a broad range of psychopathologies through its involvement in more complex human emotions such as shame and guilt, and through its effect as a negative affect emotion generating threat-interpretation biases.

Electroconvulsive therapy has acute immunological and neuroendocrine effects in patients with major depressive disorder

BACKGROUND

Major depressive disorder is associated with alterations in the neuroendocrine as well as immune system. Few studies examined the impact of electroconvulsive therapy (ECT) on these systems in patients with major depressive disorder (MDD).

METHODS

In this explorative study 12 patients suffering from medication-resistant MDD or MDD with psychotic features were studied during the first, the fifth and eleventh session of ECT. Blood samples were taken immediately prior to the electrostimulus and 5, 15 and 30 min after the electrostimulus to assess various lipopolysaccharide (LPS) stimulated or T-cell mitogen induced cytokines, immune cell numbers, Natural Killer cell activity, cortisol and ACTH.

RESULTS

Acute ECT increased the LPS-stimulated production of the cytokines IL-6 and TNF-α by peripheral monocytes but not the production of the anti-inflammatory cytokine IL-10. Acute ECT decreased T cell mitogen-induced levels of IFN-γ but IL-10 and IL-4 levels were left unaffected while NK cell activity increased momentarily but significantly. Cortisol and ACTH rose significantly after electrostimulus. Repeated ECT had no significant effect on any of the parameters.

LIMITATIONS

The study had a small group size. Also the patient group was heterogeneous as it consisted of patients with therapy-resistant depression with or without psychotic features.

CONCLUSIONS

Results suggest that acute ECT is associated with transient immunological and neuro-endocrine changes, while repeated ECT does not have an additive effect on the immune and neuroendocrine functions.