Obsessive-compulsive disorder and immunocompetence

Obsessive-Compulsive Disorder, PANDAS, and Tourette Syndrome: Immuno-inflammatory Disorders

In the last years, much focus has been given to the possible role of inflammatory and immunologic alterations in the pathophysiology of obsessive-compulsive disorder (OCD) and some related conditions, such as pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS) and Tourette syndrome (TS). Although the matter is intriguing, the available data are still controversial and/or limited. Therefore, the aim of this chapter was at reviewing and commenting on the literature on possible dysfunctions of inflammatory and immune system processes in OCD, PANDAS, and TS.This narrative review was carried out through searching PubMed and Google Scholar for English language papers from January 1985 to December 31, 2021.The data gathered up to now would suggest that the mechanisms involved might be heterogeneous according to the age of the patients and the disorder examined. Indeed, PANDAS seem more related to infections triggering autoimmunity not necessarily following group A beta-hemolytic streptococcal (GABHS) infection, as supposed in the past. Autoimmunity seems also important in TS, if coupled with an individual vulnerability that can be genetic and/or environmental. The data in adult OCD, albeit scattered and sometimes obtained in small samples of patients, would indicate that immune system and inflammatory processes are involved in the pathophysiology of the disorder. However, it is still unclear to conclude whether they are primary or secondary phenomena.In conclusion, taken together, the current findings pave that way towards novel and promising domains to explore the pathophysiology of OCD and related disorders, as well towards the development of innovative therapeutic strategy beyond current pharmacological paradigms.

Paediatric Acute onset Neuropsychiatric Syndrome: Exploratory study finds no evidence of HLA class II association but high rate of autoimmunity in first-degree relatives

AIM

Paediatric acute-onset neuropsychiatric syndrome (PANS) is defined by an acute onset of obsessive-compulsive disorder and/or eating restrictions and at least two other severe neuropsychiatric symptoms. The condition is suspected to have an immune-mediated pathophysiology, but reliable biomarkers have not been identified.

METHODS

We hypothesised that PANS, like narcolepsy, might have a human leucocyte antigen (HLA) association, as found in 95% of children developing narcolepsy after H1N1 immunisation. Low resolution genotyping of the MHC class II antigens HLA-DRB1 and HLA-DQB1 was performed using two different PCR-based methods. In addition, parents were interviewed regarding a detailed family history of autoimmune diseases in first-degree relatives. A total of 18 children, aged 5-14 (mean 8.2) years at onset of PANS met symptom criteria.

RESULTS

No evident association between PANS and the specific HLA alleles examined was observed. In first-degree relatives of 10 of the 18 children, an autoimmune disease had been diagnosed, and three of the 18 children themselves had an autoimmune disease.

CONCLUSION

No HLA allele association such as seen in children with narcolepsy after H1N1 immunisation could be confirmed in this group of children with PANS. However, more than half the group had a first-degree relative with a diagnosed autoimmune disease.

Searching for host immune-microbiome mechanisms in obsessive-compulsive disorder: A narrative literature review and future directions

Obsessive-compulsive disorder (OCD) is disabling and often treatment-refractory. Host immunity and gut microbiota have bidirectional communication with each other and with the brain. Perturbations to this axis have been implicated in neuropsychiatric disorders, but immune-microbiome signaling in OCD is relatively underexplored. We review support for further pursuing such investigations in OCD, including: 1) gut microbiota has been associated with OCD, but causal pathogenic mechanisms remain unclear; 2) early environmental risk factors for OCD overlap with critical periods of immune-microbiome development; 3) OCD is associated with increased risk of immune-mediated disorders and changes in immune parameters, which are separately associated with the microbiome; and 4) gut microbiome manipulations in animal models are associated with changes in immunity and some obsessive-compulsive symptoms. Theoretical pathogenic mechanisms could include microbiota programming of cytokine production, promotion of expansion and trafficking of peripheral immune cells to the CNS, and regulation of microglial function. Immune-microbiome signaling in OCD requires further exploration, and may offer novel insights into pathogenic mechanisms and potential treatment targets for this disabling disorder.

The Glutamate and the Immune Systems: New Targets for the Pharmacological Treatment of OCD

BACKGROUND

In the last decades the pharmacological treatment of obsessivecompulsive disorder (OCD) has been significantly promoted by the effectiveness of selective serotonin (5-HT) reuptake inhibitors (SSRIs) and the subsequent development of the 5-HT hypothesis of OCD. However, since a large majority of patients (between 40% and 60 %) do not respond to SSRIs or strategies based on the modulation of the 5-HT system, it is now essential to search for other possible therapeutic targets.

AIMS

The aim of this paper was to review current literature through a PubMed and Google Scholar search of novel hypotheses and related compounds for the treatment of OCD, with a special focus on the glutammate and the immune systems.

DISCUSSION

The literature indicates that glutamate, the main excitatory neurotransmitter, might play an important role in the pathophysiology of OCD. In addition, a series of clinical studies also supports the potential efficacy of drugs modulating the glutamate system. The role of the immune system alterations in OCD in both children and adults needs to be more deeply elucidated. In children, a subtype of OCD has been widely described resulting from infections driven by group A streptococcus β-hemolitic and belonging to the so-called "pediatric autoimmune neuropsychiatric disorders associated with streptococcus" (PANDAS). In adults, available findings are meager and controversial, although interesting.

CONCLUSION

The glutamate and the immune systems represent two intriguing topics of research that hold promise for the development of open novel treatment strategies in OCD.

Initial findings of striatum tripartite model in OCD brain samples based on transcriptome analysis

Obsessive-compulsive disorder (OCD) is a psychiatric disorder characterized by obsessions and/or compulsions. Different striatal subregions belonging to the cortico-striato-thalamic circuitry (CSTC) play an important role in the pathophysiology of OCD. The transcriptomes of 3 separate striatal areas (putamen (PT), caudate nucleus (CN) and accumbens nucleus (NAC)) from postmortem brain tissue were compared between 6 OCD and 8 control cases. In addition to network connectivity deregulation, different biological processes are specific to each striatum region according to the tripartite model of the striatum and contribute in various ways to OCD pathophysiology. Specifically, regulation of neurotransmitter levels and presynaptic processes involved in chemical synaptic transmission were shared between NAC and PT. The Gene Ontology terms cellular response to chemical stimulus, response to external stimulus, response to organic substance, regulation of synaptic plasticity, and modulation of synaptic transmission were shared between CN and PT. Most genes harboring common and/or rare variants previously associated with OCD that were differentially expressed or part of a least preserved coexpression module in our study also suggest striatum subregion specificity. At the transcriptional level, our study supports differences in the 3 circuit CSTC model associated with OCD.

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.

Gloster A, Meyer AH, Lieb R. Physical diseases among persons with obsessive compulsive symptoms and disorder: a general population study

PURPOSE

This study aimed at evaluating the comorbidity between DSM-IV obsessive compulsive disorder (OCD) and subthreshold forms and physical diseases in the general population as well as disability associated with comorbidity.

METHODS

We used data from the 1998 German Mental Health Survey, a representative survey of the German population. Mental disorders and physical diseases of 4181 subjects (aged 18-65) were cross-sectionally assessed. Mental disorders were diagnosed using the M-CIDI/DIA-X interview. Physical diseases were assessed through a self-report questionnaire and a standardized medical interview. We created three groups of obsessive-compulsive symptoms: (1) no obsessive compulsive symptoms (n = 3,571); (2) obsessive compulsive symptoms (OCS, n = 371; endorsement of OCS (either obsession or compulsion) without fulfilling any core DSM-IV criteria); (3) subthreshold OCD/OCD (n = 239; fulfilling either some or all of the core DSM-IV criteria).

RESULTS

In comparison to subjects without OCS, subjects with subthreshold OCD/OCD showed higher prevalence rates of migraine headaches (OR 1.7; 95% CI 1.1-2.5) and respiratory diseases (OR 1.7; 95% CI 1.03-2.7); subjects with OCS showed higher prevalence rates of allergies (OR 1.6; 95% CI 1.1-2.8), migraine headaches (OR 1.9; 95% CI 1.4-2.7) and thyroid disorders (OR 1.4; 95% CI 1.01-2.0). Subjects with both OCS and physical disease reported the highest number of days of disability due to physical or psychological problems during the past 30 days compared to subjects with only OCS, only physical disease or neither of them.

CONCLUSIONS

OCD and subthreshold forms are associated with higher comorbidity rates with specific physical diseases and higher disability than subjects without OCS. Possible etiological pathways should be evaluated in future studies and clinicians in primary care should be aware of these associations.

The association between arthritis and psychiatric disorders; results from a longitudinal population-based study

BACKGROUND

To disentangle cross-sectionally and longitudinally the relationship between arthritis and psychiatric disorders, and to examine the relationship between age and incidence of (1) any psychiatric disorder among respondents with and without arthritis and (2) arthritis among respondents with and without any psychiatric disorder.

METHODS

Data are from the Netherlands Mental Health Survey and Incidence Study (NEMESIS), a nationally representative household survey with repeated measurements in 1996, 1997 and 1999. Self-report was used to ascertain arthritis. Psychiatric and substance use disorders were diagnosed with the WHO Composite International Diagnostic Interview.

RESULTS

Regarding the cross-sectional results, it was found that the strength of the association of arthritis with mood and anxiety disorders was similar [odds ratio (OR)=1.48, 95% confidence interval (CI)=1.09-1.99 and OR=1.42, 95% CI=1.11-1.81, respectively]. The longitudinal results showed that preexisting arthritis elevated the risk of developing any mood disorder (OR=1.94, 95% CI=1.23-3.07), whereas having any mood or any anxiety disorder did not predict new-onset arthritis. The incidence of any psychiatric disorder was significantly higher among younger persons (<45 years) with arthritis, compared to others in the same age category without arthritis.

CONCLUSIONS

Arthritis is associated with psychiatric disorders. The temporal relationship points to one direction: arthritis predicts new onset of psychiatric disorder (mood disorder) instead of the reverse. Especially younger people (<45 years) with arthritis are at risk of developing a psychiatric disorder. Screening and simultaneous treatment of comorbid mood disorder and arthritis are recommended as part of routine in primary care.

Normalisation of immune cell imbalance after pharmacological treatments of patients suffering from obsessive-compulsive disorder

Recent data have shown the presence of immunological alterations in adult patients suffering from obsessive-compulsive disorder (OCD). The objective of this study was to examine the possible effects of 12 months of treatment with different serotonergic drugs, such as clomipramine and selective serotonin reuptake inhibitors (SSRIs) on peripheral immunological cells of 18 OCD patients. Both the absolute number and percent of CD4+, CD8+, CD3+, CD19+ and CD56+ cells were measured in peripheral blood before and after treatment by means of a Facstar Flow Sorter apparatus. At baseline, all patients showed a significant increase of CD8+ and decrease of CD4+ lymphocytes when compared with a similar group of healthy control subjects; after the treatment, CD8+ and CD4+ cells, respectively, decreased and increased significantly, and the CD4+/CD8+ ratio increased, when compared with baseline values, in parallel with the clinical improvement. These data suggest that the alterations of immune cells reported in patients with OCD at baseline may be reverted by treatment with SRIs and should be considered a state-dependent marker, perhaps related to a condition of stress.

Immunity and acquired alterations in cognition and emotion: lessons from SLE

Classic immunologic teaching describes the brain as an immunologically privileged site. Studies of neuroimmunology have focused for many years almost exclusively on multiple sclerosis, a disease in which inflammatory cells actually infiltrate brain tissue, and the rodent model of this disease, experimental allergic encephalitis. Over the past decade, however, increasingly, brain-reactive antibodies have been demonstrated in the serum of patients with numerous neurological diseases. The contribution these antibodies make to neuronal dysfunction has, in general, not been determined. Here, we describe recent studies showing that serum antibodies to the N-methyl-D-aspartate receptor occur frequently in patients with systemic lupus erythematosus and can cause alterations in cognition and behavior following a breach in the blood-brain barrier.

Assessing the validity of current mouse genetic models of obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is a disorder characterized by unwanted and intrusive thoughts, images, or impulses and/or repetitive behavior. OCD is a major cause of disability; however, the genetic factors and pathophysiological mechanisms underlying this complex, heterogeneous disorder remain largely unknown. During the past decade, a number of putative mouse genetic models of OCD have been developed for the purpose of studying the neural mechanisms underlying this disorder and developing novel treatments. This review presents and evaluates these experimental preparations to date. Models using knockout or transgenic approaches, as well as those examining variation in genetically diverse populations, are evaluated and discussed.

Obsessive compulsive disorder in adults with rheumatic heart disease

OBJECTIVE

There are considerable data on the possible association between streptococcal infection and obsessive compulsive disorder (OCD), particularly the relation between Sydenham's chorea (SC) and OCD. However, neuropsychiatric sequelae related to streptococcal infection are mainly reported in children. In this preliminary study, we examined prevalence of OCD in a group of adult subjects with established rheumatic heart disease (RHD). We hypothesized that the rate of OCD would be higher than the known general population rates.

METHOD

One hundred adult subjects with RHD were evaluated for OCD and other comorbid psychiatric disorders using well-known psychiatric assessment tools. A qualified psychiatrist conducted the assessments. The diagnoses were made according to DSM-IV criteria.

RESULTS

The rate of clinical OCD and subclinical OCD was 10% and 3%, respectively (n = 13), a rate much higher than the 1-3% rate reported in general population. Of the 13 subjects, only three had a history of SC (23%).

CONCLUSIONS

OCD could be a long-term sequel in adults with a history of rheumatic fever in childhood, even in the absence of frank chorea. The findings call for systematic research in this little explored area.

Immunology of obsessive-compulsive disorder

Childhood OCD often develops into a chronic illness that lasts decades. Proof that some type of immunotherapy (such as antibiotic prophylaxis) could significantly reduce recurrence or exacerbation of symptoms of OC or tics would suggest a supportive role for immune triggers in the onset or worsening of these conditions and provide additional tools for improving outcome. The validity of PANDAS will continue to be questioned, however,because demonstrating a clear causation will be difficult on a background ofa common childhood illness. Along with the previously mentioned immuno-therapy study, validation of the PANDAS phenotype (broadly interpreted)would be advanced from new and continued research in the following areas: (1) prospective studies to identify infectious triggers in the onset and exacerbations of OCD spectrum disorders, (2) biological measures for immune and genetic susceptibility, and (3) large scale epidemiological studies demonstrating the relationship between infection and OCD spectrum disorders. The assimilation of these study results should allow for elucidation of the immune system's role in the onset and maintenance of OCD.

Psychoneuroimmunodermatology of atopic dermatitis: from empiric data to the evolutionary hypothesis

Atopic dermatitis is a pruritic skin disease affecting predominantly young people. There is evidence that psychologic stress constitutes an increased risk for atopy and influences the disease's clinical course. This risk is believed mediated by the effects of stress on neuroimmunoregulation, which in turn modulates the hypersensitivity response and involves immunoglobulin E-mediated inflammation, helper T-cell 2 predominance, and eosinophilia. This article examines theoretic perspectives and other behavioral dimensions, such as maternal caring behavior, infant response to stress, temperament, and the so-called "hygiene hypothesis." The Darwinian framework and the mental scenario are examined. These processes may be akin to the generation of antibodies by the immune system.

Obsessive-compulsive disorder following brain injury: a review

OBJECTIVE

This article reviews obsessive-compulsive disorder (OCD) following acquired brain injury. OCD type symptomatology without any other cognitive, behavioral, or emotional problems following a brain injury appears to be rare. However, the first onset of obsessions and compulsions following a brain injury has been described, but cognitive impairments can potentially color the presentation.

METHOD

This article reviews obsessive-compulsive disorder (OCD) after brain injury, including traumatic brain injury, cerebrovascular accidents, brain tumors and brain infections. Overlapping symtomatology between OCD and brain injury is discussed.

RESULTS

Findings regarding the neuro-imaging of OCD after brain injury are reviewed and integrated with neuropsychological data from studies with idiopathic OCD.

CONCLUSION

There appears to be some convergance between findings from studies of the neuropsychology of idiopathic OCD and neuro-imaging of OCD following brain injury.

Mental health concerns of HIV-infected gay and bisexual men seeking mental health services: an observational study

Addressing mental health concerns of HIV-positive individuals is an important component of providing quality HIV care. Mental health intake information from patients with HIV can be an important source of data to complement existing research on HIV and mental health because the intake information contains concerns that are both from the perspective of the patients and are significant enough to bring them into treatment. The current study describes the mental health intake information of HIV-positive men who have sex with men (MSM) at an urban community health clinic over a 1-year period. This information included presenting problems, current symptoms from a symptom checklist, ratings of impairments in functioning, and client histories (e.g., substance abuse, emotional, physical, and sexual abuse, previous treatment). It also included clinicians' Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) diagnoses of the participants, and recommended treatments. Depression was the most prevalent presenting problem (58.1% of clients), followed by anxiety (38.2%). Consistently, depression (96.3%) and low energy (78.2%) were the most frequently endorsed symptoms on a symptom checklist, followed by anxiety (69.2%). HIV-specific problems also played a large role both directly, as a presenting problem, and indirectly as they related to such concerns as relationship issues. Axis I diagnoses included adjustment disorders (50.0%), major depressive disorder (21.4%), and dysthymia (a less severe but more chronic depression) (8.9%). This review highlights the mental health issues that HIV-positive MSM feel are significant enough to require treatment. Because mental health is a key component of overall quality of life, HIV providers who work with MSM can use these data to increase awareness of the types of mental concerns that are most distressing to this population.

Sociality, stress, and the corpus striatum of the green anolis lizard

The green anolis lizard, Anolis carolinensis, is a uniquely convenient species with great potential for providing insights about the causes and consequences of social behavior from an evolutionary perspective. In this species, social interactions are mediated by visual displays in which specific units of behavior are combined in various ways to communicate several more-or-less specific messages. Two related research programs that utilize this species converge in provocative ways to provide insight into this phenomenon. The first program is centered on the basal ganglia, now known to be crucial to the expression of aggressive territoriality in this species, and the second research program examines the way the physiological stress response is involved in aggression and its subsequent adaptive outcomes. Both the neural and the neuroendocrine systems affect the progress of social interactions as well as the subsequent social dominance relationships when combatants subsequently live together. Further, because body color depends almost exclusively on the stress response, skin color provides a unique in situ bioassay of otherwise inaccessible information about the animal's internal state. The fullest understanding of the physiological ethology of this model species will depend on an interdisciplinary approach that considers both proximate (physiological) and ultimate (evolutionary) causes of displays. Questions thus arising include how the nervous system controls and assembles the specific units of behavior-motor patterns and autonomic reflexes-into displays that are adaptive in specific contexts.