Schizophrenia in patients with atopic disorders with particular emphasis on asthma: a Danish population-based study

Immune Dysfunction in Schizophrenia Spectrum Disorders

Evidence from epidemiological, clinical, and biological research resulted in the immune hypothesis: the hypothesis that immune system dysfunction is involved in the pathophysiology of schizophrenia spectrum disorders (SSD). The promising implication of this hypothesis is the potential to use existing immunomodulatory treatment for innovative interventions for SSD. Here, we provide a selective historical review of important discoveries that have shaped our understanding of immune dysfunction in SSD. We first explain the basic principles of immune dysfunction, after which we travel more than a century back in time. Starting our journey with neurosyphilis-associated psychosis in the nineteenth century, we continue by evaluating the role of infections and autoimmunity in SSD and findings from assessment of immune function using new techniques, such as cytokine levels, microglia density, neuroimaging, and gene expression. Drawing from these findings, we discuss anti-inflammatory interventions for SSD, and we conclude with a look into the future.

Multimorbidity and the Etiology of Schizophrenia

PURPOSE OF REVIEW

A global study of multimorbidity in schizophrenia, especially of the association with physical conditions, might offer much needed etiological insights.

RECENT FINDINGS

Our review suggests that life-style factors and medication related to schizophrenia are only part of the explanation of the increase in risk for cardiovascular, metabolic, pulmonary disorders, and some cancers. Positive associations with autoimmune disorders (with the exception of rheumatoid arthritis) and epilepsy are promising avenues of research but to date have not been fully exploited. The same holds for the negative comorbidity seen for rheumatoid arthritis and some cancers (e.g., prostate). As a whole, our review suggests that most of the explored conditions have a different prevalence in schizophrenia than in the general population. Several hypotheses emerged from this review such as the role of immune and genetic factors, of sex hormones, and of more general variability factors.

Neuropsychiatric disorders in adults with atopic dermatitis: A population-based cohort study

BACKGROUND

Atopic dermatitis (AD) may be associated with an increased burden of neuropsychiatric outcomes such as anxiety and depression, but longitudinal data on the impact of AD severity is lacking, and a comprehensive assessment of neuropsychiatric disease in adults with AD is needed.

OBJECTIVES

Determine risk of incident neuropsychiatric disease among adults with AD by severity.

METHODS

A cohort study using electronic health records data from UK general practices from 1994 to 2015. Adults (≥18 years) with AD were matched on age, practice and index date to patients without AD. AD severity was categorized using treatments and dermatology referrals. Outcomes were incident anxiety, depression, bipolar disorder, schizophrenia, attention-deficit/hyperactivity disorder (ADHD), autism, obsessive-compulsive disorder (OCD), suicidality and completed suicide.

RESULTS

Comparing 625,083 adults with AD to 2,678,888 adults without AD, AD was associated with higher risk of anxiety [HR 1.14 (1.13-1.15)], depression [1.14 (1.13-1.15)] and OCD [1.48 (1.38-1.58)] across all severities. Mild or moderate AD was also associated with higher risk of autism, ADHD, bipolar disorder and suicidality.

CONCLUSIONS

Atopic dermatitis is associated with a higher risk of multiple neuropsychiatric conditions, but these risks differ by specific condition and AD severity. Clinicians should inquire about mental health in patients with AD.

Multimorbidity clusters among people with serious mental illness: a representative primary and secondary data linkage cohort study

BACKGROUND

People with serious mental illness (SMI) experience higher mortality partially attributable to higher long-term condition (LTC) prevalence. However, little is known about multiple LTCs (MLTCs) clustering in this population.

METHODS

People from South London with SMI and two or more existing LTCs aged 18+ at diagnosis were included using linked primary and mental healthcare records, 2012-2020. Latent class analysis (LCA) determined MLTC classes and multinominal logistic regression examined associations between demographic/clinical characteristics and latent class membership.

RESULTS

The sample included 1924 patients (mean (s.d.) age 48.2 (17.3) years). Five latent classes were identified: 'substance related' (24.9%), 'atopic' (24.2%), 'pure affective' (30.4%), 'cardiovascular' (14.1%), and 'complex multimorbidity' (6.4%). Patients had on average 7-9 LTCs in each cluster. Males were at increased odds of MLTCs in all four clusters, compared to the 'pure affective'. Compared to the largest cluster ('pure affective'), the 'substance related' and the 'atopic' clusters were younger [odds ratios (OR) per year increase 0.99 (95% CI 0.98-1.00) and 0.96 (0.95-0.97) respectively], and the 'cardiovascular' and 'complex multimorbidity' clusters were older (ORs 1.09 (1.07-1.10) and 1.16 (1.14-1.18) respectively). The 'substance related' cluster was more likely to be White, the 'cardiovascular' cluster more likely to be Black (compared to White; OR 1.75, 95% CI 1.10-2.79), and both more likely to have schizophrenia, compared to other clusters.

CONCLUSION

The current study identified five latent class MLTC clusters among patients with SMI. An integrated care model for treating MLTCs in this population is recommended to improve multimorbidity care.

Effects of a six-month yoga intervention on the immune-inflammatory pathway in antipsychotic-stabilized schizophrenia patients: A randomized controlled trial

BACKGROUND

Schizophrenia is a complex neuropsychiatric disorder for which several etiopathological theories have been proposed, one of the prominent ones being immune dysfunction. Recent studies on yoga as an add-on therapy have shown improvement in negative symptoms, cognition, and quality of life in schizophrenia patients. However, the biological mechanism/s of action of yoga in schizophrenia are not clear. The current study was aimed at exploring the effects of long-term (6 months) add-on yoga therapy on the immune inflammatory pathway in schizophrenia patients.

METHODS

Sixty schizophrenia patients were randomized to add-on yoga therapy (YT=30) and treatment-as-usual (TAU=30) groups of which 21 patients in YT and 20 in TAU group completed the study. Blood samples and clinical assessments were obtained at baseline and at the end of 6 months. The plasma levels of nine cytokines (IL-2, IL-4, IL-5, IL-10, IL-12(p70), IL-13, GM-CSF, IFN-γ, and TNF-α) were quantified using multiplex suspension array. The clinical assessments included SAPS, SANS, BPRS, PSS, CGI, SOFS and WHOQUOL-BREF.

RESULTS

Patients in the yoga group showed significant reductions in plasma TNF-α (Z = 2.99, p = 0.003) and IL-5 levels (Z = 2.20, p = 0.03) and greater clinical improvements in SAPS, SANS, PSS, and SOFS scores as compared to TAU group. Further, plasma TNF-α levels exhibited a positive correlation with negative symptoms (r_s =0.45, p = 0.02) and socio-occupational functioning (r_s =0.61, p = 0.002) in the YT group.

CONCLUSIONS

The findings of the study suggest that improvements in schizophrenia psychopathology with yoga interventions are associated with immuno-modulatory effects.

Atopic dermatitis and risk of major neuropsychiatric disorders in children: A population-based cohort study

BACKGROUND

Paediatric atopic dermatitis (AD) has been linked to neuropsychiatric comorbidities such as depression, anxiety and attention-deficit/hyperactivity disorder (ADHD). However, longitudinal data are limited, and the effect of AD severity on neuropsychiatric outcomes requires further characterization.

OBJECTIVES

To determine the risk of several major neuropsychiatric conditions in children with AD.

METHODS

We analysed UK health records data in a population-based cohort study. Each patient <18 years old with AD was matched to up to five unaffected patients on age, practice and index date. Treatments served as proxies for AD severity, which was analysed in a time-updated manner. Outcomes were incident anxiety, depression, bipolar disorder, schizophrenia, ADHD, autism, obsessive-compulsive disorder (OCD), suicidal ideation or attempt, and completed suicide.

RESULTS

A total of 409,431 children with AD (93.2% mild, 5.5% moderate, 1.3% severe) were compared to 1,809,029 children without AD. In Cox regression models adjusted for age, sex, socioeconomic status and other atopic comorbidities, no statistically significant relationships were observed between AD and incident anxiety (HR 1.01, 95% CI 0.99-1.03), ADHD (1.02, 0.97-1.06), autism (1.02, 0.98-1.06), bipolar disorder (1.08, 0.85-1.36), suicidal ideation/attempt (0.98, 0.95-1.01) or completed suicide (0.85, 0.64-1.14). Children with AD were less likely to develop depression (0.93, 0.91-0.95) or schizophrenia (0.72, 0.54-0.95) but more likely to develop OCD (1.26, 1.16-1.37). However, there was substantial variation by AD severity and age in both the direction and magnitude of effect for many of the neuropsychiatric conditions examined.

CONCLUSIONS

The was no substantial impact of AD on the overall risk of many neuropsychiatric conditions in children, but disease severity and age may be important modifying factors. Additional research is needed to further dissect the complex relationship between paediatric AD and neuropsychiatric comorbidities.

Evidence of innate immune dysfunction in first-episode psychosis patients with accompanying mood disorder

Background

Inflammation and increases in inflammatory cytokines are common findings in psychiatric disorders such as schizophrenia (SCZ), bipolar disorder (BD), and major depressive disorder (MDD). Meta-analyses of studies that measured circulating cytokines have provided evidence of innate inflammation across all three disorders, with some overlap of inflammatory cytokines such as IL-6 and TNF-α. However, differences across disorders were also identified, including increased IL-4 in BD that suggest different immune mechanisms may be involved depending on the type of disorder present.

Methods

We sought to identify if the presence or absence of an affective disorder in first-episode psychotic (FEP) patients was associated with variations in cytokine production after stimulation of peripheral blood mononuclear cells (PBMC). 98 participants were recruited and grouped into healthy controls (n = 45) and first-episode psychosis patients (n = 53). Psychosis patients were further grouped by presence (AFF; n = 22) or lack (NON; n = 31) of an affective disorder. We cultured isolated PBMC from all participants for 48 h at 37 °C under four separate conditions; (1) culture media alone for baseline, or the following three stimulatory conditions: (2) 25 ng/mL lipopolysaccharide (LPS), (3) 10 ng/mL phytohemagglutinin (PHA), and (4) 125 ng/ml α-CD3 plus 250 ng/ml α-CD28. Supernatants collected at 48 h were analyzed using multiplex Luminex assay to identify differences in cytokine and chemokine production. Results from these assays were then correlated to patient clinical assessments for positive and negative symptoms common to psychotic disorders.

Results

We found that PBMC from affective FEP patients produced higher concentrations of cytokines associated with both innate and adaptive immunity after stimulation than non-affective FEP patients and healthy controls. More specifically, the AFF PBMC produced increased tumor necrosis fctor (TNF)-α, interleukin (IL)-1β, IL-6, and others associated with innate inflammation. PBMC from AFF also produced increased IL-4, IL-17, interferon (IFN)γ, and other cytokines associated with adaptive immune activation, depending on stimulation. Additionally, inflammatory cytokines that differed at rest and after LPS stimulation correlated with Scale for the Assessment of Negative Symptoms (SANS) scores.

Conclusions

Our findings suggest that immune dysfunction in affective psychosis may differ from that of primary psychotic disorders, and inflammation may be associated with increased negative symptoms. These findings could be helpful in determining clinical diagnosis after first psychotic episode.

Back to the Future: The Role of Infections in Psychopathology. Focus on OCD

OBJECTIVE

Recently, there has been a resurgence of interest in the relationship between infections and psychopathology, given the increasing data on the neurotropism and neurological/psychiatric morbidity of the SARS-COV2 virus, responsible for the current worldwide pandemic. Although the majority of observations were those obtained in mood and schizophrenic disorders, a few data are also available on the presence of bacterial or viral infections in patients suffering from obsessive-compulsive disorder (OCD). Therefore, given the limited information, the present paper aimed at reviewing the most updated evidence of infections in neuropsychiatric disorders and their possible mechanisms of actions, with a narrow focus on microbes in OCD.

METHOD

This paper is a narrative review. The databases of PubMed, Scopus, Embase, PsycINFO and Google Scholar were accessed to research and collect English language papers published between 1 January 1980 and 31 December 2021. The data on PANDAS/PANS and those observed during severe brain infections were excluded.

RESULTS

Several pathogens have been associated with an increased risk to develop a broad spectrum of neuropsychiatric conditions, such as schizophrenia, mood disorders, autism, attention-deficit/hyperactivity disorder, anorexia nervosa, and post-traumatic stress disorder. Some evidence supported a possible role of infections also in the pathophysiology of OCD. Infections from Herpes simplex virus 1, Borna disease virus, Group A-Beta Hemolytic Streptococcus, Borrelia spp., and Toxoplasma gondii were actually found in patients with OCD. Although different mechanisms have been hypothesized, all would converge to trigger functional/structural alterations of specific circuits or immune processes, with cascade dysfunctions of several other systems.

CONCLUSIONS

Based on the current evidence, a possible contribution of different types of microbes has been proposed for different neuropsychiatric disorders including OCD. However, the currently available literature is meager and heterogeneous in terms of sample characteristics and methods used. Therefore, further studies are needed to better understand the impact of infectious agents in neuropsychiatric disorders. Our opinion is that deeper insights in this field might contribute to a better definition of biological underpinnings of specific clinical pictures, as well as to promote psychiatric precision medicine, with treatments based on altered pathological pathways of single patients. This might be particularly relevant in OCD, a disorder with a high proportion of patients who are resistant or do not respond to conventional therapeutic strategies.

Diagnostic progression to schizophrenia in 35,255 patients with obsessive-compulsive disorder: a longitudinal follow-up study

Evidence suggests a continuity between obsessive-compulsive disorder (OCD) and schizophrenia. However, the factors that may predict diagnostic progression from OCD to schizophrenia remain unclear. A total of 35,255 adolescents and adults with OCD (ICD-9-CM code: 300.3) were enrolled between 2001 and 2010 and followed up at the end of 2011 for the identification of de novo schizophrenia (ICD-9-CM code: 295). The Kaplan-Meier method was used to estimate incidence rates, and the Cox regression was used to determine the significance of candidate predictors. At the end of the 11-year follow-up period, the crude cumulative progression rate from OCD to schizophrenia was 6%, and the estimated progression rate totaled 7.80%. Male sex (hazard ratio: 1.23), obesity (1.77), autism spectrum disorder (1.69), bipolar disorder (1.69), posttraumatic stress disorder (1.65), cluster A personality disorder (2.50), and a family history of schizophrenia (2.57) also were related to an elevated likelihood of subsequent progression to schizophrenia in patients with OCD. Further study is necessary to elucidate the exact pathomechanisms underlying diagnostic progression to schizophrenia in patients with OCD.

Novel disease associations with schizophrenia genetic risk revealed in ~400,000 UK Biobank participants

Schizophrenia is a serious mental disorder with considerable somatic and psychiatric morbidity. It is unclear whether comorbid health conditions predominantly arise due to shared genetic risk or consequent to having schizophrenia. To explore the contribution of genetic risk for schizophrenia, we analysed the effect of schizophrenia polygenic risk scores (PRS) on a broad range of health problems in 406 929 individuals with no schizophrenia diagnosis from the UK Biobank. Diagnoses were derived from linked health data including primary care, hospital inpatient records, and registers with information on cancer and deaths. Schizophrenia PRS were generated and tested for associations with general health conditions, 16 ICD10 main chapters, and 603 diseases using linear and logistic regressions. Higher schizophrenia PRS was significantly associated with poorer overall health ratings, more hospital inpatient diagnoses, and more unique illnesses. It was also significantly positively associated with 4 ICD10 chapters: mental disorders; respiratory diseases; digestive diseases; and pregnancy, childbirth and the puerperium, but negatively associated with musculoskeletal disorders. Thirty-one specific phenotypes were significantly associated with schizophrenia PRS, and the 19 novel findings include several musculoskeletal diseases, respiratory diseases, digestive diseases, varicose veins, pituitary hyperfunction, and other peripheral nerve disorders. These findings extend knowledge of the pleiotropic effect of genetic risk for schizophrenia and offer insight into how some conditions often comorbid with schizophrenia arise. Additional studies incorporating the genetic basis of hormone regulation and involvement of immune mechanisms in the pathophysiology of schizophrenia may further elucidate the biological mechanisms underlying schizophrenia and its comorbid conditions.

Effects of prenatal nutrient supplementation and early life exposures on neurodevelopment at age 10: a randomised controlled trial - the COPSYCH study protocol

INTRODUCTION

Nutrient deficiency and immune and inflammatory disturbances in early life may compromise neurodevelopment and be implicated in the aetiology of psychiatric disorders. However, current evidence is limited by its predominantly observational nature. COpenhagen Prospective Study on Neuro-PSYCHiatric Development (COPSYCH) is a research alliance between Copenhagen Prospective Studies on Asthma in Childhood (COPSAC) and Center for Clinical Intervention and Neuropsychiatric Schizophrenia Research with the overall aim to investigate effects of prenatal and early life exposures on neurodevelopment at 10 years. COPSYCH will investigate the impact of prenatal n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA) and high-dose vitamin D supplementation on neurodevelopment reflected by brain development, neurocognition and psychopathology. Moreover, the neurodevelopmental impact of early life exposures such as infections, low grade inflammation and the gut microbiome will be scrutinised.

METHODS AND ANALYSIS

COPSYCH is based on the prospective and ongoing COPSAC2010 birth cohort of 700 mother-child pairs. Randomised controlled trials of supplementation with n-3 LCPUFA and/or high-dose vitamin D or placebo in the third trimester were embedded in a factorial 2×2 design (ClinicalTrials.gov: NCT01233297 and NCT00856947). This unique cohort provides deep phenotyping data from 14 previous clinical follow-up visits and exposure assessments since birth. The ongoing 10-year visit is a 2-day visit. Day 1 includes a comprehensive neurocognitive examination, and assessment of psychopathological dimensions, and assessment of categorical psychopathology. Day 2 includes acquisition of brain structural, diffusion and functional sequences using 3 Tesla MRI. Study outcomes are neurocognitive, psychopathological and MRI measures.

ETHICS AND DISSEMINATION

This study has been approved by the Danish National Committee on Health Research Ethics and The Danish Data Protection Agency. The study is conducted in accordance with the guiding principles of the Declaration of Helsinki. Parents gave written informed consent before enrolment.

The association of asthma, atopic dermatitis, and allergic rhinitis with peripartum mental disorders

BACKGROUND

Atopic diseases are characterized by dysregulated inflammatory response, which may incur the onset of peripartum mental disorders, but the impact remains unknown. This study examined whether and to what extent the history of atopic diseases is associated with newly onset peripartum mental disorders.

METHODS

Using population-based registries, we identified all primiparous women who gave birth to live singletons in Denmark during 1978-2016 (n = 937,422). The exposure was hospital contact due to the three major types of atopic diseases-asthma, atopic dermatitis, and allergic rhinitis-before conception. The primary outcome was any hospital contact for mental disorder during pregnancy and 1-year postpartum, which was further classified into affective disorders, neurotic, stress-related and somatoform disorders, and substance abuse. The follow-up started from the date of conception and ended at the date of the first diagnosis of mental disorders, 1-year postpartum, death, emigration, or December 31, 2016, whichever came first. Cox regression was used, adjusted for calendar year, age at childbirth, education, residence, and Charlson comorbidity index.

RESULTS

A total of 24,016 (2.6%) women received diagnosis of at least one of the three atopic diseases before conception (asthma, 1.7%; atopic dermatitis, 0.6%; and allergic rhinitis, 0.8%). Exposure to asthma, atopic dermatitis, or allergic rhinitis was associated with a 37% increased overall risk of peripartum mental disorders (hazard ratio [HR], 1.37; 95% confidence interval [CI], 1.27-1.49). Higher risks were observed among women with more frequent hospital contacts for atopic disease (HR, 1.80; 95% CI, 1.37-2.35; ≥5 times), and with recent hospital contacts for atopic disease (HR, 1.74; 95% CI, 1.48-2.06; within 2 years before conception). Specific associations were observed between asthma and neurotic, stress-related and somatoform disorders (HR, 1.40; 95% CI, 1.21-1.62), and between atopic dermatitis and substance abuse (HR, 1.62; 95% CI, 1.12-2.34).

CONCLUSIONS

History of asthma, atopic dermatitis, and allergic rhinitis before conception was associated with increased risks of peripartum mental disorders. Women who have atopic diseases before pregnancy may benefit from systematic mental health monitoring.

[Neurodevelopmental Disorders, Psychiatric Comorbidities and Associated Pathologies in Patients with Childhood-Onset Schizophrenia and Premorbid Autistic Symptoms.]

INTRODUCTION

Childhood-Onset Schizophrenia (COS) is a rare (1/40000), severe and neurodevelopmental form of schizophrenia beginning before 13 years of age. Little is known about comorbidities and specific COS-related disorders. Thus, the objective of our study was to evaluate them from a psychiatric, neurodevelopmental and somatic perspective.

METHOD

This is an ancillary study of the GenAuDiss protocol. A standardized psychiatric interview (K-SADS-PL DSM5) and a neuropsychological assessment (WISC-V/WAIS-IV) were carried out in outpatients with COS as well as a medical history collection concerning pregnancy, perinatal period, development, biography and medical and psychiatric, personal, and family history.

RESULTS

20 outpatients were included. The mean age of onset of COS was 8.90 years (+/- 2.30). Psychiatric comorbidities (DSM5) were Attention Deficit Hyperactivity Disorder (15/20 patients), Anxiety Disorders (14/20) and Autism Spectrum Disorder (13/20). The average IQ was 70.26 (+/- 18.09). A language delay and a break in school career were noted in 18/20 patients. Finally, the main associated somatic disorder was asthma (15/20 patients).

DISCUSSION

We highlighted in our patients with COS a high frequency of comorbidities including at least one systematic psychiatric disorder. However, although COS is a severe condition impacting the patient, his family and society, its management remains essentially symptomatic. In clinical practice, it is necessary to look for all these comorbidities and to manage them in order to improve the overall quality of care.

Changes in oral corticosteroid use in asthma treatment-A 20-year Danish nationwide drug utilisation study

Oral corticosteroids (OCS) are used in asthma management but can cause serious adverse effects. We aimed to investigate the usage trends in a nationwide asthma cohort in Denmark from 1999 to 2018. Using national registers, we identified young adults (18-45 years) with two or more asthma drug collections within 12 months since the age of 15 years as indicative of active asthma. OCS exposure level was stratified as high use (≥5 mg prednisolone/day/year) and low use (<5 mg/day/year). Lorenz curves were computed to illustrate potential skewness of consumption among the OCS users. We identified 318 950 individuals with a median age of 29 years (IQR 20-38 years) whereof 57% were women. The 1-year prevalence of OCS users was stable at 4.8% (median, IQR 4.7%-4.8%), but with nearly 40% decrease in high-users from 0.54% in 1999 to 0.33% in 2018. The median annual exposure decreased from 500 mg/year (1999) to 250 mg/year (2018). We found a substantial skewness in the distribution of OCS usage with 10% of users accounting for almost 50% of all OCS use. The prevalence of OCS users among young adults with active asthma has been relatively stable from 1999 to 2018, but with a decreasing prevalence of high-users and annual consumption.

Childhood atopic dermatitis as a precursor for developing attention deficit/hyperactivity disorder

Atopic dermatitis (AD) is a skin disease characterized by chronic inflammatory condition that shows hallmark presentations in terms of sleep disturbances, pruritus, and psychological stress, and an association with increased attention deficit/hyperactivity disorder (ADHD) risk. A number of studies have suggested for the co-occurrence of the two diseased conditions. In terms of global prevalence, AD and ADHD almost exhibit a parallel increment according to epidemiological data. In addition, recent reports indicate AD to show a temporal association with later onset of ADHD. Although several studies suggest for the potential link between AD and ADHD, currently there is no definitive answer to this regard. Furthermore, epidemiological evidence of co-occurrence does not ascertain a pathophysiological link between the two conditions. The pathophysiological basis behind the association of AD and ADHD also remain poorly elucidated. The objective of this review is to present an extensive account of AD and associated comorbidities with a special attention toward ADHD as well as to elaborate on the mechanisms underlying their association. The review can provide healthcare providers with the recent updates on AD-ADHD association and help them while dealing with such patients. In general, AD and ADHD show a positive association in majority of the cross-sectional studies. However, large longitudinal studies are required to draw any conclusion on the temporal nature of such association.

Atopic dermatitis and psychosocial comorbidities

Atopic dermatitis (AD) is a chronic inflammatory disease that may be associated with a number of comorbidities including psychosocial disorders, which are the primary focus of this article. The data presented is based on a literature search in PubMed and subsequent screening of relevant review articles and guidelines. There is a greater prevalence of depression, anxiety, sleep disorders and suicidal ideation among individuals with AD. The disease negatively impacts patients' quality of life. Children with AD have been shown to more commonly exhibit signs of attention-deficit/hyperactivity disorder. Only little data exists on the association of AD with schizophrenia, eating disorders or obsessive-compulsive disorder. There is a great need for research in the field of AD-related comorbidities, especially with respect to the question as to whether and how novel treatment options may potentially affect these comorbidities.

The other side of atopic dermatitis: An evaluation of psychosocial comorbidities

Atopic dermatitis is a chronic skin disease that commonly affects patients. In addition to its effects on the skin, it has also been associated with other physical, psychosocial, and economic burdens along with numerous debilitating comorbidities. More recently, research has focused on the psychosocial and mental health aspect of atopic dermatitis, which has remained controversial. We reviewed the current literature and have discussed the association of atopic dermatitis with suicide, attention-deficit/hyperactivity disorder, and schizophrenia.

A link among schizophrenia, diabetes, and asthma: Role of Ca2+/cAMP signaling

Asthma has been associated with an increased risk for developing schizophrenia. In addition, schizophrenia has been associated with an increased risk for developing type 2 diabetes mellitus, resulting in an elevated cardiovascular risk and in a limited life expectancy. It is well discussed that dysregulations related to Ca2+ signaling could link these diseases, in addition to cAMP signaling pathways. Thus, revealing this interplay among schizophrenia, diabetes, and asthma may provide novel insights into the pathogenesis of these diseases. Publications involving Ca2+ and cAMP signaling pathways, schizophrenia, diabetes, and asthma (alone or combined) were collected by searching PubMed and EMBASE. Both Ca2+ and cAMP signaling pathways (Ca2+/cAMP signaling) control the release of neurotransmitters and hormones, in addition to airway smooth muscle contractility, then dysregulations of these cellular processes may be involved in these diseases. Taking into consideration, the experience of our group in this field, this narrative review debated the involvement of Ca2+/cAMP signaling in this link among schizophrenia, diabetes, and asthma, including its pharmacological implications.

Effects of parental mental illness on children's physical health: systematic review and meta-analysis

BACKGROUND

Children of parents with mental disorder face multiple challenges.

AIMS

To summarise evidence about parental mental disorder and child physical health.

METHOD

We searched seven databases for cohort or case-control studies quantifying associations between parental mental disorders (substance use, psychotic, mood, anxiety, obsessive-compulsive, post-traumatic stress and eating) and offspring physical health. Studies were excluded if: they reported perinatal outcomes only (<28 days) or outcomes after age 18; they measured outcome prior to exposure; or the sample was drawn from diseased children. A meta-analysis was conducted. The protocol was registered on the PROSPERO database (CRD42017072620).

RESULTS

Searches revealed 15 945 non-duplicated studies. Forty-one studies met our inclusion criteria: ten investigated accidents/injuries; eight asthma; three other atopic diseases; ten overweight/obesity; ten studied other illnesses (eight from low-and middle-income countries (LMICs)). Half of the studies investigated maternal perinatal mental health, 17% investigated paternal mental disorder and 87% examined maternal depression. Meta-analysis revealed significantly higher rates of injuries (OR = 1.15, 95% CI 1.04-1.26), asthma (OR = 1.26, 95% CI 1.12-1.41) and outcomes recorded in LMICs (malnutrition: OR = 2.55, 95% CI 1.74-3.73; diarrhoea: OR = 2.16, 95% CI 1.65-2.84). Evidence was inconclusive for obesity and other atopic disorders.

CONCLUSIONS

Children of parents with mental disorder have health disadvantages; however, the evidence base is limited to risks for offspring following postnatal depression in mothers and there is little focus on fathers in the literature. Understanding the physical health risks of these vulnerable children is vital to improving lives. Future work should focus on discovering mechanisms linking physical and mental health across generations.

DECLARATION OF INTEREST

None.

Role of Infection, Autoimmunity, Atopic Disorders, and the Immune System in Schizophrenia: Evidence from Epidemiological and Genetic Studies

An immunologic component to schizophrenia has been increasingly recognized, where infections and chronic inflammatory diseases as atopic disorders and autoimmune diseases could be involved in the pathogenesis of schizophrenia. Psychotic symptoms can be directly triggered by infections reaching the CNS, or be secondary to systemic inflammation indirectly affecting the brain through immune components, such as brain-reactive antibodies and cytokines. Large-scale epidemiological studies have consistently displayed that infections, autoimmune diseases, and atopic disorders are associated with increased risk of schizophrenia and that schizophrenia is associated with increased levels of immune markers at diagnosis. However, since there is also an increased risk of immune-related diseases after the diagnosis with schizophrenia and in family members of individuals with schizophrenia, parts of the association could also be due to heritable factors. Shared genetic factor might account for some of this increased prevalence of immune-related diseases among individuals with schizophrenia, and indeed the most pronounced genetic association with schizophrenia lies within the HLA region, which is one of the most important regions for the immune system. However, genetic studies have shown that the common genetic variants associated with schizophrenia do not seem to increase the susceptibility for acquiring infections. Nonetheless, shared genes with the susceptibility for acquiring infections not captured by the polygenic risk score for schizophrenia could still influence the association.

Atopy Increases Risk of Psychotic Experiences: A Large Population-Based Study

Introduction: Building upon the comorbidity between atopy and schizophrenia, we conducted a large cross-sectional, observational population-based study to examine if such associations also exist between atopic disorders (eczema, allergic rhinitis, and asthma) and nonclinical psychotic experiences. Methods: We examined psychotic experiences in a Dutch population sample through an online survey (≥14 years of age). Participants filled out the Questionnaire for Psychotic Experiences, together with questions screening for atopic disorders (eczema, allergic rhinitis, and asthma). Prevalence rates were calculated; binary logistic regression was used to determine odds ratios (ORs) (age, gender, and years of education as covariates). Results: We included 6,479 participants. Individuals diagnosed with one or more atopic disorders had an increased risk of psychotic experiences as compared with controls (OR = 1.26). Analysis of individual symptoms revealed an OR of 1.27 for hallucinations, whereas delusions only showed a trend. With each additional atopic disorder, the risk of psychotic experiences increased. This was also observed for hallucinations alone but not for delusions alone. Atopy was associated with hallucinations across all modalities (OR ranging from 1.19 to 1.40). These results did not appear to be driven specifically by any one of the atopic disorders. Conclusion: In the largest population sample of adolescents and adults to date, we found that atopic disorders (asthma, eczema, and allergic rhinitis) increase the risk of psychotic experiences, in a dose-response fashion. These results provide further support for the role of immunological components in the predisposition for psychosis and can serve as a base for further research.

Association between prior somatic disease and 5-year relapse risk among 11,856 incident patients with schizophrenia

BACKGROUND

Somatic diseases have been associated with an increased risk for subsequent schizophrenia; however, it is unknown whether prior somatic diseases negatively affect early treatment outcomes after a first-time schizophrenia diagnosis.

METHODS

We included all individuals born in Denmark after January 1^st, 1977 and first-time diagnosed with schizophrenia between January 1^st, 1996 and December 31^st, 2015. We identified all life-time somatic hospital contacts and all prescriptions within the year before the first-time schizophrenia diagnosis and followed patients for up to five years regarding risk for schizophrenia (re)-hospitalization (relapse). We performed Cox regression analyses calculating hazard rate ratios (HRR) including 95%-confidence intervals (CI) and adjusted for relevant confounders.

RESULTS

We followed a total of 11,856 patients with a first-time schizophrenia diagnosis (58.7% male, mean age 23.1 (SD = 4.7) years) for 39,033 person-years, whereof 5506 (46.4%) had relapse with schizophrenia re-hospitalization during 5-year of follow-up. Somatic hospital contacts ever before (95.4%; HRR = 1.30; 95%-CI = 1.07-1.59), and specifically during the year before schizophrenia diagnosis (42.5%; HRR = 1.36; 95%-CI = 1.11-1.66) were associated with an increased risk of schizophrenia relapse as were a greater number of prior somatic hospital contacts (p < 0.001). Individuals with up to four different prescriptions for somatic medications showed a trend towards a slightly lower risk of relapse.

CONCLUSION

Somatic diseases and health seeking patterns might have an impact on the course of schizophrenia, where severe somatic comorbidity, specifically during the year before first-time schizophrenia diagnosis, seem to negatively affect early treatment course, whereas previous somatic medication use may indicate a better compliance and help-seeking behavior.

Childhood and Parental Asthma, Future Risk of Bipolar Disorder and Schizophrenia Spectrum Disorders: A Population-Based Cohort Study

BACKGROUND

Mounting evidence implicates early life and prenatal immune disturbances in the etiology of severe mental illnesses. Asthma is a common illness associated with chronic aberrant immune responses. We aimed to determine if asthma in childhood and parents is associated with bipolar and schizophrenia spectrum disorders.

METHODS

A cohort study including all children born in Sweden 1973-1995 (N > 2 million) assessing associations between childhood hospitalization for asthma, parental asthma during and pre-pregnancy, and subsequent bipolar and schizophrenia spectrum disorders.

RESULTS

Children with hospitalizations for asthma between 11 and 15 years had increased rates of bipolar (adjusted hazard ratio [aHR] = 1.73, 95% confidence interval [CI] = 1.21-2.47) and schizophrenia spectrum disorders (aHR = 1.62, 95% CI = 1.08-2.42). However, there was no association with asthma before aged 11. These results were supported by an analysis of siblings discordant for asthma. We found an association between both maternal and paternal asthma and bipolar disorder (aHR = 1.60, 95% CI = 1.27-2.02, and aHR = 1.44, 95% CI = 1.08-1.93, respectively), but not between parental asthma and schizophrenia spectrum disorders.

CONCLUSIONS

As far as we are aware, this is the first study to find increased risk of bipolar disorder in children of individuals with asthma. Asthma admissions before aged 11 do not appear to be linked to bipolar or schizophrenia spectrum disorders. Taken together, our results do not suggest a straightforward link between asthma and severe mental illness via neurodevelopmental effects of inflammation, but potentially there is shared genetic vulnerability. This finding has implications for understanding the differential pathogenic mechanisms of bipolar and schizophrenia spectrum disorders.

Hand-biting Lesions in a Child — a Challenging Diagnosis

Background: Self-induced skin lesions, especially in young children, can create confusion within pediatricians, dermatologists, or other medical care providers, leading to different diagnoses, unnecessary investigations, and delaying the correct therapeutic psychiatric evaluation.

Case report: We report the case of a 4-year-old boy who was referred to Dermatology after being hospitalized in the Allergy Department for a chronic allergic contact dermatitis. He had been previously diagnosed with chronic hand dermatitis, atopic dermatitis, and psoriasis, and treated with no favorable outcome. Scaly erythematous plaques were noticed on the dorsal aspects of both hands and on the lateral folds of the fingers. The skin lesions were distributed in a non-symmetrical way. A diagnosis of self-injurious behavior was presumed, and psychiatric evaluation was asked. The child was transferred to the Psychiatry Department, and a diagnosis of schizophrenia was concluded.

Major Comorbidities of Atopic Dermatitis: Beyond Allergic Disorders

The consequences of atopic dermatitis reach beyond the skin and past childhood. Patients with atopic dermatitis are at risk of developing allergic comorbidities, but less is known about the associations between atopic dermatitis and non-allergic conditions. Understanding these non-allergic comorbidities has the potential to improve patient outcomes and to help mitigate the cost and burdens associated with these conditions. Atopic dermatitis is associated with cutaneous bacterial infections, more severe forms/courses of cutaneous viral infections, and extra-cutaneous infections. Atopic dermatitis is also associated with several mental health comorbidities particularly attention-deficit hyperactivity disorder, anxiety, and depression. Data are largely inconsistent for specific cancers, but atopic dermatitis appears to protect against malignancy overall; severe long-term atopic dermatitis is associated with adult lymphomas. Atopic dermatitis may also be associated with obesity, cardiovascular disease, and autoimmune disease, particularly alopecia areata and gastrointestinal immune-mediated disorders. Although the causative mechanisms underlying these associations are poorly understood, treating physicians should be aware of associations in seeking to alleviate the burden for patients with atopic dermatitis.

Glucocorticoids and the risk of schizophrenia spectrum disorder in childhood and adolescence - A Danish nationwide study

Glucocorticoids can have psychosis as a potential side effect, but have also been suggested to yield protective effects due to anti-inflammatory properties. Nonetheless, knowledge is sparse on the association between glucocorticoid treatment and development of psychosis, which we aimed to study in this first large-scale longitudinal study. Among all individuals born in Denmark 1995-2003 (n=597,257), we compared individuals who had redeemed ≥1 prescription for glucocorticoids to an active comparator group and a non-exposed group concerning subsequent development of schizophrenia spectrum disorders until 2013. Hazard rate ratios (HRR) were estimated using Cox regression adjusted for calendar year, age, gender, urbanization, somatic diseases, parental educational level and psychiatric history. The risk for a subsequent diagnosis of early-onset schizophrenia spectrum disorder (N=1141) was increased after exposure to both non-systemic (HRR=1.47; 95%-CI=1.25-1.73; N=371) and systemic glucocorticoids (HRR=1.66; 95%-CI=1.13-2.43; N=34), when compared to non-exposed individuals. Similar elevated risks were observed when comparing to the active comparator group, for schizophrenia and acute psychosis, and within an older cohort. The risk of psychosis was elevated the most within the first year after exposure to glucocorticoids (P<0.001) without any indication for a dose-response association. However, in individuals with asthma, exposure to glucocorticoids did not further increase the risk of psychosis. Glucocorticoid exposure was associated with an increased risk for psychotic disorders, which may be explained by an effect of the underlying somatic disease, such as asthma. A potential beneficial effect of glucocorticoids on psychotic symptoms should be investigated in clinical trials.

IL-33/ST2 Pathway and Galectin-3 as a New Analytes in Pathogenesis and Cardiometabolic Risk Evaluation in Psychosis

Schizophrenia and treatment of this disorder are often accompanied with metabolic syndrome and cardiovascular issues. Alterations in the serum level of innate immune mediators, such as interleukin-33 (IL-33) and its receptor IL-33R (ST2) and Galectin-3 (Gal-3) were observed in these conditions. Moreover, these parameters are potential prognostic and therapeutic markers. There is also accumulating evidence that these molecules play a role in neuroinflammation. Therefore, in this study we have investigated the serum level of Gal-3, IL-33 and soluble ST2 (sST2) in different stages of schizophrenia. Gal-3 levels were elevated in remission and lower in schizophrenia exacerbation in comparison with controls. Levels of IL-33 and sST2 are higher in schizophrenia exacerbation in comparison with controls and patients in remission. This initial analysis of new markers of neuroinflammation suggested their involvement in schizophrenia pathophysiology and/or cardiometabolic comorbidity.

Interplay of Brain-Derived Neurotrophic Factor and Cytokines in Schizophrenia

Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family and plays an important role in neuroplasticity, differentiation and survival of neurons, as well as their function. Neuroinflammation has been explored in the pathophysiology of many mental disorders, such as schizophrenia. Cytokines representing different types of immune responses have an impact on neurogenesis and BDNF expression. Cross-regulation of BDNF and cytokines is accomplished through several signalling pathways. Also, typical and atypical antipsychotic drugs variously modulate the expression of BDNF and serum levels of cytokines, which can possibly be used in evaluation of therapy effectiveness. Comorbidity of metabolic syndrome and atopic diseases has been considered in the context of BDNF and cytokines interplay in schizophrenia.

Association of psychosis, affective disorders and diseases affecting the immune system

Purpose of the article: There are indications of altered immune activity in depressed and psychotic patients compared to healthy controls in several studies. To explore the clinical importance of this phenomenon we examined the relation between different disorders affecting the immune system and psychoses and depression, respectively.

MATERIALS AND METHODS

A total of 276 patients consecutively admitted to a psychiatric acute ward were included in the study. Of these 41 patients fulfilled the criteria for ICD-10 F20-29 (psychotic) diagnosis and 157 patients a F30-39 (affective) diagnosis. Information on diseases affecting the immune system in patients themselves and family members of the patients were obtained by a self-report questionnaire.

RESULTS

Comparing the two groups showed a significant correlation between the F20-29 group and eczema (r = -0.116, p = .037). Comparing what patients reported for family members showed a significantly higher frequency of epilepsy (p = .033) in the F20-29 group. Summarizing all immunological diseases for family members showed a significantly higher frequency in the F30-39 group compared to the F20-29 group (χ² = 4, 82, df = 1, p = .028).

CONCLUSIONS

There may be differences between the F20-29 and F30-39 groups and their family members regarding risk for diseases affecting the immune system. This is in line with different activity of the immune system measured in blood for the disorders and may add information regarding etiology and pathology of these psychiatric diseases. Further studies including a greater number of subjects, as well as confirmation of the immunological diseases through blood samples are needed.

Association between TAAR6 polymorphisms and airway responsiveness to inhaled corticosteroids in asthmatic patients

BACKGROUND

Genetic polymorphisms may be responsible for the wide variation in response to inhaled corticosteroids in asthmatic patients. We had previously reported that one polymorphism rs7772821, located on the 3'-UTR of trace amine-associated receptor 6 (TAAR6), is significantly associated with percentile changes in the forced expiratory volume in 1 s (%ΔFEV1) after inhaled corticosteroid treatment in asthmatics using a genome-wide association study. The aim of the present study was to validate the association between 15 single-nucleotide polymorphisms (SNPs) on the TAAR6 and airway responsiveness to inhaled corticosteroids in the asthmatics.

METHODS

The %ΔFEV1 induced by 4 weeks' treatment with inhaled fluticasone propionate (1000 μg daily) was measured in 246 asthmatics. The 15 SNPs of TAAR6 were genotyped using a TaqMan assay. An association analysis between %ΔFEV1 and TAAR6 polymorphisms was carried out using a linear regression model controlling for age, sex, smoking status, presence of atopy, and baseline FEV1 as covariates.

RESULTS

Among the 15 SNPs and seven haplotypes of TAAR6, rs7772821 (T>G) on the 3'-UTR showed the strongest correlation with inhaled corticosteroid-induced %ΔFEV1 (Pcorr=0.002 in the codominant model, Pcorr=0.03 in the dominant model, Pcorr=0.01 in the recessive model). The %ΔFEV1 of the rs7772821T>G minor homozygotes (60.77%) was higher than that of patients harboring either the rs7772821 T/G or T/T genotypes (21.32 and 31.60%, respectively).

CONCLUSION

The TAAR6 rs7772821 polymorphism may be one of the important genetic factors for predicting the response to treatment with inhaled corticosteroids in asthmatics.

Carbonyl Stress and Microinflammation-Related Molecules as Potential Biomarkers in Schizophrenia

This literature review primarily aims to summarize our research, comprising both cross-sectional and longitudinal studies, and discuss the possibility of using microinflammation-related biomarkers as peripheral biomarkers in the diagnosis and monitoring of patients with schizophrenia. To date, several studies have been conducted on peripheral biomarkers to recognize the potential markers for the diagnosis of schizophrenia and to determine the state and effects of therapy in patients with schizophrenia. Research has established a correlation between carbonyl stress, an environmental factor, and the pathophysiology of neuropsychiatric diseases, including schizophrenia. In addition, studies on biomarkers related to these stresses have achieved results that are either replicable or exhibit consistent increases or decreases in patients with schizophrenia. For instance, pentosidine, an advanced glycation end product (AGE), is considerably elevated in patients with schizophrenia; however, low levels of vitamin B6 [a detoxifier of reactive carbonyl compounds (RCOs)] have also been reported in some patients with schizophrenia. Another study on peripheral markers of carbonyl stress in patients with schizophrenia revealed a correlation of higher levels of glyceraldehyde-derived AGEs with higher neurotoxicity and lower levels of soluble receptors capable of diminishing the effects of AGEs. Furthermore, studies on evoked microinflammation-related biomarkers (e.g., soluble tumor necrosis factor receptor 1) have reported relatively consistent results, suggesting the involvement of microinflammation in the pathophysiology of schizophrenia. We believe that our cross-sectional and longitudinal studies as well as various previous inflammation marker studies that could be interpreted from several perspectives, such as mild localized encephalitis and microvascular disturbance, highlighted the importance of early intervention as prevention and distinguished the possible exclusion of inflammations in schizophrenia.

Immunopsychiatry: important facts

Accumulating evidence indicate a role for the immune system particularly inflammation and autoimmunity in the aetiology of major psychiatric disorders such as depression and schizophrenia. In this paper, we discuss some of the key advances in immunopsychiatry in order to highlight to psychiatrists and other health professionals how an increased understanding of this field might enhance our knowledge of illness mechanism and approaches to treatment. We present a brief overview of clinical research that link inflammation and autoimmunity with depression and psychosis, including potential role of inflammation in treatment response, current evidence for the effectiveness of immune-modulating treatment for depression and psychosis, and possible role of inflammation in common physical comorbidities for these disorders such as coronary heart disease and diabetes mellitus. Gaining a better understanding of the role of immune system could be paradigm changing for psychiatry. We need collaborations between clinicians and scientists to deliver high-quality translational research in order to fully realise the clinical potential of this exciting and rapidly expanding field.

Mental Health Services Claims and Adult Onset Asthma in Ontario, Canada

BACKGROUND

Living with asthma is associated with a decrease in quality of life due to reductions in activities of daily living and increased psychological stress, both of which are associated with poor mental health outcomes.

OBJECTIVE

The objective of this study was to quantify the burden of mental disorders on the adult asthma population and compare the risk of mental health services claims (MHSCs) in the 1 year before and 1 year after asthma diagnosis.

METHODS

Ontario residents aged 25 to 65 years with incident physician-diagnosed asthma between April 1, 2005, and March 31, 2012, were included. MHSCs, which consisted of hospitalizations, emergency department (ED), and outpatient physician visits, were identified from universal health administrative data. Poisson regression models with repeated measures were used to estimate the relative risk (RR) of MHSCs for 2 time periods: 1 year after asthma diagnosis compared with the 1 year before and 2 years after compared with 2 years before.

RESULTS

A total of 145,881 adults had incident asthma. In the 1 year after asthma diagnosis, 27% had an MHSC. The risk of ED visits for any mental disorders increased by 13% in the 1 year after asthma diagnosis compared with the 1 year before (adjusted RR [aRR], 1.13; 95% confidence interval [CI], 1.06-1.21). This increased risk of ED visits was not found when comparing 2 years after asthma diagnosis with 2 years before. The risk for outpatient physician visits for substance-related disorders increased by 21% at 1 year (aRR, 1.21; 95% CI, 1.14-1.28) and 37% at 2 years (aRR, 1.37; 95% CI, 1.28-1.46).

CONCLUSIONS

The significant comorbid burden of mental disorders in adults with newly diagnosed asthma highlights the need for primary care physicians to assess mental health needs and provide appropriate care.

Asthma, corticosteroid use and schizophrenia: A nationwide population-based study in Taiwan

OBJECTIVE

Asthma and corticosteroid use have been implicated as possible risk factors for schizophrenia. The retrospective cohort study herein aimed to investigate the association between asthma, corticosteroid use, and schizophrenia.

METHOD

Longitudinal data (2000 to 2007) from adults with asthma (n = 50,046) and without asthma (n = 50,046) were compared on measures of schizophrenia incidence using Taiwan's National Health Insurance Research Database (NHIRD). Incidence of schizophrenia diagnosis (ICD-9 codes 295.XX) between 2000 and 2007 were compared between groups. Competing risk-adjusted Cox regression analyses were conducted, adjusting for sex, age, residence, socioeconomic status, corticosteroid use, outpatient and emergency room visit frequency, Charlson comorbidity index, and total length of hospital stays days for any disorder.

RESULTS

Of the 75,069 subjects, 238 received a diagnosis of schizophrenia. The mean (SD) follow-up interval for all subjects was 5.8 (2.3) years. After adjusting for potential confounding factors, asthma was associated with significantly greater hazard ratio for incident schizophrenia 1.40 (95% CI = 1.05, 1.87). Additional factors associated with greater incidence of schizophrenia were rural residence, lower economic status, and poor general health. Older age (i.e. ≥65 years) was negatively associated with schizophrenia incidence. Corticosteroid use was not associated with increased risk for schizophrenia.

CONCLUSIONS

Asthma was associated with increased risk for schizophrenia. The results herein suggest that a convergent disturbance in the immune-inflammatory system may contribute to the pathoetiology of asthma and schizophrenia.

Childhood interleukin-6, C-reactive protein and atopic disorders as risk factors for hypomanic symptoms in young adulthood: a longitudinal birth cohort study

BACKGROUND

There are no existing longitudinal studies of inflammatory markers and atopic disorders in childhood and risk of hypomanic symptoms in adulthood. This study examined if childhood: (1) serum interleukin-6 (IL-6) and C-reactive protein (CRP); and (2) asthma and/or eczema are associated with features of hypomania in young adulthood.

METHOD

Participants in the Avon Longitudinal Study of Parents and Children, a prospective general population UK birth cohort, had non-fasting blood samples for IL-6 and CRP measurement at the age of 9 years (n = 4645), and parents answered a question about doctor-diagnosed atopic illness before the age of 10 years (n = 7809). These participants completed the Hypomania Checklist at age 22 years (n = 3361).

RESULTS

After adjusting for age, sex, ethnicity, socio-economic status, past psychological and behavioural problems, body mass index and maternal postnatal depression, participants in the top third of IL-6 values at 9 years, compared with the bottom third, had an increased risk of hypomanic symptoms by age 22 years [adjusted odds ratio 1.77, 95% confidence interval (CI) 1.10-2.85, p < 0.001]. Higher IL-6 levels in childhood were associated with adult hypomania features in a dose-response fashion. After further adjustment for depression at the age of 18 years this association remained (adjusted odds ratio 1.70, 95% CI 1.03-2.81, p = 0.038). There was no evidence of an association of hypomanic symptoms with CRP levels, asthma or eczema in childhood.

CONCLUSIONS

Higher levels of systemic inflammatory marker IL-6 in childhood were associated with hypomanic symptoms in young adulthood, suggesting that inflammation may play a role in the pathophysiology of mania. Inflammatory pathways may be suitable targets for the prevention and intervention for bipolar disorder.

Serum C-reactive protein in adolescence and risk of schizophrenia in adulthood: A prospective birth cohort study

OBJECTIVE

Meta-analyses of cross-sectional studies confirm an increase in circulating inflammatory markers during acute psychosis. Longitudinal studies are scarce but are needed to understand whether elevated inflammatory markers are a cause or consequence of illness. We report a longitudinal study of serum C-reactive protein (CRP) in adolescence and subsequent risk of schizophrenia and related psychoses in adulthood in the Northern Finland Birth Cohort 1986.

METHOD

Serum high-sensitivity CRP was measured at age 15/16 years in 6362 participants. ICD-10 diagnoses of schizophrenia and related psychoses were obtained from centralised hospital inpatient and outpatient registers up to age 27 years. Logistic regression calculated odds ratios (ORs) for psychotic outcomes associated with baseline CRP levels analysed as both continuous and categorical variables using American Heart Association criteria. Age, sex, body mass index, maternal education, smoking, and alcohol use were included as potential confounders.

RESULTS

By age 27years, 88 cases of non-affective psychosis (1.38%), of which 22 were schizophrenia (0.35%), were identified. Adolescent CRP was associated with subsequent schizophrenia. The adjusted OR for schizophrenia by age 27yearsfor each standard deviation (SD) increase in CRP levels at age 15/16yearswas 1.25 (95% CI, 1.07-1.46), which was consistent with a linear, dose-response relationship (P-value for quadratic term 0.23). Using CRP as a categorical variable, those with high (>3mg/L) compared with low (<1mg/L) CRP levels at baseline were more likely to develop schizophrenia; adjusted OR 4.25 (95% CI, 1.30-13.93). There was some indication that higher CRP was associated with earlier onset of schizophrenia (rs=-0.40; P=0.07).

CONCLUSIONS

A longitudinal association between adolescent CRP levels and adult schizophrenia diagnosis indicates a potentially important role of inflammation in the pathogenesis of the illness, although the findings, based on a small number of cases, need to be interpreted with caution and require replication in other samples.

Influence of Polygenic Risk Scores on the Association Between Infections and Schizophrenia

BACKGROUND

Several studies have suggested an important role of infections in the etiology of schizophrenia; however, shared genetic liability toward infections and schizophrenia could influence the association. We therefore investigated the possible effect of polygenic risk scores (PRSs) for schizophrenia on the association between infections and the risk of schizophrenia.

METHODS

We conducted a nested case-control study on a Danish population-based sample born after 1981 comprising of 1692 cases diagnosed with schizophrenia between 1994 and 2008 and 1724 matched controls. All individuals were linked utilizing nationwide population-based registers with virtually complete registration of all hospital contacts for infections. PRSs were calculated using discovery effect size estimates weights from an independent meta-analysis (34,600 cases and 45,968 control individuals).

RESULTS

A prior hospital contact with infection had occurred in 41% of the individuals with schizophrenia and increased the incidence rate ratio (IRR) of schizophrenia by 1.43 (95% confidence interval [CI] = 1.22-1.67). Adding PRS, which was robustly associated with schizophrenia (by an IRR of 1.46 [95% CI = 1.34-1.60] per standard deviation of the score), did not alter the association with infections and the increased risk of schizophrenia remained (IRR = 1.41; 95% CI = 1.20-1.66). Furthermore, there were no interactions between PRS and infections on the risk of developing schizophrenia (p = .554). Neither did PRS affect the risk of acquiring infections among patients with schizophrenia (odds ratio = 1.00; 95% CI = 0.89-1.12) nor among controls (odds ratio = 1.09; 95% CI: 0.96-1.24).

CONCLUSIONS

PRS and a history of infections have independent effects on the risk for schizophrenia, and the common genetic risk measured by PRS did not account for the association with infection in this sample.

Serum IL-4 and IL-10 Levels Correlate with the Symptoms of the Drug-Naive Adolescents with First Episode, Early Onset Schizophrenia

OBJECTIVE

In this study, it was aimed to understand the underlying possible immunopathogenesis of first episode, early onset schizophrenia (EOS) through profiling the T helper 1 (Th₁) cell cytokines TNF-α, IFN-γ, and IL-2, Th₂ cell cytokines IL-4 and IL-10, Th₁₇ cell cytokine IL-17A, and inflammatory cytokine IL-6.

METHODS

The study included a total of 30 children, admitted to child psychiatry outpatient clinic aged between 10 and 17 years of age, who had not received prior therapy and were diagnosed with psychosis according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) as the patient group, and 26 age- and gender-matched children as the control group. Structured psychiatric interviews (K-SADS-PL and PANSS) were conducted with all participants. The BD Cytokine Bead Array Human Th₁/Th₂/Th₁₇ Cytokine Kit is used for the measurement of serum cytokines, for example, IL-2, IL-4, IL-6, IL-10, IL-17A, TNF-α, and IFN-γ.

RESULTS

There was no significant difference between groups in terms of IL-2, IL-4, IL-6, IL-10, IL-17A, TNF-α, and IFN-γ levels (p > 0.05). However, there was a significant correlation between IL-10 and IL-4 with negative symptoms of EOS (r = -0.65, p = 0.02 and r = 0.67, p = 0.02, respectively).

CONCLUSION

IL4 and IL-10 levels have a relationship with negative symptoms of disease. Therefore, this study might suggest that immunological processes might have a role in the disease pathophysiology.

Network analysis of genes and their association with diseases

A plethora of network-based approaches within the Systems Biology universe have been applied, to date, to investigate the underlying molecular mechanisms of various human diseases. In the present study, we perform a bipartite, topological and clustering graph analysis in order to gain a better understanding of the relationships between human genetic diseases and the relationships between the genes that are implicated in them. For this purpose, disease-disease and gene-gene networks were constructed from combined gene-disease association networks. The latter, were created by collecting and integrating data from three diverse resources, each one with different content covering from rare monogenic disorders to common complex diseases. This data pluralism enabled us to uncover important associations between diseases with unrelated phenotypic manifestations but with common genetic origin. For our analysis, the topological attributes and the functional implications of the individual networks were taken into account and are shortly discussed. We believe that some observations of this study could advance our understanding regarding the etiology of a disease with distinct pathological manifestations, and simultaneously provide the springboard for the development of preventive and therapeutic strategies and its underlying genetic mechanisms.

Is there a role for immune-to-brain communication in schizophrenia?

Schizophrenia is characterised by hallucinations, delusions, depression-like so-called negative symptoms, cognitive dysfunction, impaired neurodevelopment and neurodegeneration. Epidemiological and genetic studies strongly indicate a role of inflammation and immunity in the pathogenesis of symptoms of schizophrenia. Evidence accrued over the last two decades has demonstrated that there are a number of pathways through which systemic inflammation can exert profound influence on the brain leading to changes in mood, cognition and behaviour. The peripheral immune system-to-brain communication pathways have been studied extensively in the context of depression where inflammatory cytokines are thought to play a key role. In this review, we highlight novel evidence suggesting an important role of peripheral immune-to-brain communication pathways in schizophrenia. We discuss recent population-based longitudinal studies that report an association between elevated levels of circulating inflammatory cytokines and subsequent risk of psychosis. We discuss emerging evidence indicating potentially important role of blood-brain barrier endothelial cells in peripheral immune-to-brain communication, which may be also relevant for schizophrenia. Drawing on clinical and preclinical studies, we discuss whether immune-mediated mechanisms could help to explain some of the clinical and pathophysiological features of schizophrenia. We discuss implication of these findings for approaches to diagnosis, treatment and research in future. Finally, pointing towards links with early-life adversity, we consider whether persistent low-grade activation of the innate immune response, as a result of impaired foetal or childhood development, could be a common mechanism underlying the high comorbidity between certain neuropsychiatric and physical illnesses, such as schizophrenia, depression, heart disease and type-two diabetes.

Emerging Comorbidities in Adult Asthma: Risks, Clinical Associations, and Mechanisms

Asthma is a heterogeneous disease with many phenotypes, and age at disease onset is an important factor in separating the phenotypes. Most studies with asthma have been performed in patients being otherwise healthy. However, in real life, comorbid diseases are very common in adult patients. We review here the emerging comorbid conditions to asthma such as obesity, metabolic syndrome, diabetes mellitus type 2 (DM2), and cardiac and psychiatric diseases. Their role as risk factors for incident asthma and whether they affect clinical asthma are evaluated. Obesity, independently or as a part of metabolic syndrome, DM2, and depression are risk factors for incident asthma. In contrast, the effects of comorbidities on clinical asthma are less well-known and mostly studies are lacking. Cross-sectional studies in obese asthmatics suggest that they may have less well controlled asthma and worse lung function. However, no long-term clinical follow-up studies with these comorbidities and asthma were identified. These emerging comorbidities often occur in the same multimorbid adult patient and may have in common metabolic pathways and inflammatory or other alterations such as early life exposures, systemic inflammation, inflammasome, adipokines, hyperglycemia, hyperinsulinemia, lung mechanics, mitochondrial dysfunction, disturbed nitric oxide metabolism, and leukotrienes.

Atopic Diseases and Subsequent Ischemic Stroke Among Patients With Schizophrenia: A Nationwide Longitudinal Study

BACKGROUND

Chronic inflammation plays an important role in schizophrenia and atopic diseases, and studies have suggested that chronic inflammation is associated with an increased risk of stroke. The role of atopic diseases in the development of stroke among patients with schizophrenia is still unknown.

METHODS

A total of 63,913 patients with schizophrenia without a stroke history between 2002 and 2008 and 63,913 age- and sex-matched controls were included and followed up to the end of 2011. Patients with schizophrenia and the reference group were divided into subgroups based on the presence or absence of atopic diseases. Individuals who developed stroke during follow-up were identified.

RESULTS

Patients with schizophrenia had an increased risk of developing ischemic stroke (no atopic disease: hazard ratio [HR] = 2.18, 95% confidence interval [CI] = 1.88-2.53; with atopic disease: HR = 3.11, 95% CI = 2.63-3.69) compared with the reference group without atopic diseases. Among patients with schizophrenia, the presence of atopic diseases increased the risk of developing ischemic stroke (HR = 1.44, 95% CI = 1.24-1.66), with a cumulative relationship between greater numbers of atopic comorbidities and a greater risk of ischemic stroke (one atopic disease: HR = 1.39, 95% CI = 1.19-1.63; two atopic comorbidities: HR = 1.48, 95% CI = 1.10-2.00; at least 3 atopic comorbidities: HR = 2.81, 95% CI = 1.55-5.12).

CONCLUSIONS

The combined presence of schizophrenia and atopic diseases is associated with an increased risk of ischemic stroke in later life compared with individuals without these conditions.

Increase systemic levels of IL-23 as a possible constitutive marker in schizophrenia

Inflammation appears to play significant role in schizophrenia. IL-23 is key molecule in mediating IL-17 dependent inflammatory response. Therefore, we analyzed the serum concentrations of IL-23 levels in patients with first episode psychosis (78 subjects), in patients with acute exacerbation of schizophrenia who were already treated with antipsychotics (47 subjects) and healthy controls (35 subjects). Diagnoses were established using International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10). Psychopathology was evaluated using the Positive and Negative Syndrome Scale (PANSS) and serum levels of IL-23 were measured using sensitive enzyme-linked immunosorbent assay (ELISA). Serum levels of IL-23 were higher in patients with first psychotic episode and in patients with schizophrenia in relapse than in healthy subjects (p=0.000) and no difference was established between these two groups of patients before therapy. Also, after 4 weeks of antipsychotic therapy levels of IL-23 remains elevated in both groups of patients with no differences between two groups. It appears that increased level of IL-23 in psychotic patients independently of antipsychotic therapy can be a constitutive marker in this disorder.

Somatic diseases and conditions before the first diagnosis of schizophrenia: a nationwide population-based cohort study in more than 900 000 individuals

OBJECTIVE

Schizophrenia is associated with excess physical comorbidity. Yet, to our knowledge, large studies are lacking on the associations with somatic diseases before the onset of schizophrenia. The authors conducted a nationwide study of the full spectrum of treated somatic diseases before the first diagnosis of schizophrenia.

METHOD

Nationwide sample of the Danish population consisting of singletons (n = 954351) born 1977-1993 and followed from birth to 2009, during which period 4371 developed schizophrenia. Somatic diagnoses at all general hospital contacts (admitted or outpatient care at a somatic hospital) from 1977 to 2009 were used as exposures. The incidence rate ratio (IRR) of schizophrenia was calculated using Poisson regression adjusted for confounders.

RESULTS

Among the 4371 persons who developed schizophrenia from 1992 to 2009, a total of 4180 (95.6%) persons had a previous somatic hospital contact. A history of any somatic hospital contact was associated with an elevated risk of schizophrenia (IRR = 2.04, 95% CI = 1.77-2.37). A wide range of somatic diseases and conditions were associated with an increased risk of schizophrenia, including epilepsy (IRR = 2.26, 95% CI = 1.93-2.62), nutritional or metabolic disorders (IRR = 1.57, 95% CI = 1.39-1.77), circulatory system diseases (IRR = 1.63, 95% CI= 1.38-1.92), and brain injury (IRR = 1.58, 95% CI = 1.45-1.72).

CONCLUSIONS

A wide range of potential etiological factors could have contributed to the observed associations, including genetic or physiological overlaps between conditions, and interacting immunological, behavioral, and neurodevelopmental factors.

The Role of Infections and Autoimmune Diseases for Schizophrenia and Depression: Findings from Large-Scale Epidemiological Studies

An immunologic component to schizophrenia and depression has been increasingly recognized, which has led to extensive research into the associations with infections and autoimmune diseases. Large-scale nationwide epidemiological studies have displayed an increased prevalence of both autoimmune diseases and infections among persons with schizophrenia and depression. Autoimmune diseases, and especially the number of infections requiring hospitalization, increase the risk of schizophrenia and depression in a dose–response relationship. Infections are a common exposure and a broad spectrum of infections are associated with schizophrenia and depression. Particularly the autoimmune diseases with a potential presence of brain-reactive antibodies were associated with psychiatric disorders. However, the associations seem to be bidirectional, since the risk of autoimmune diseases and infections is also increased after diagnosis with schizophrenia and depression. The risk of autoimmune diseases was particularly increased in individuals with prior hospital contacts for infections.

It has been suggested that inflammation and autoimmunity could be involved in the etiology and pathogenesis of some patients with symptoms of schizophrenia and depression. The psychiatric symptoms can be directly triggered by immune components, such as brain-reactive antibodies and cytokines, or infections reaching the central nervous system (CNS), or be secondary to systemic inflammation indirectly affecting the brain. However, the associations could also be caused by shared genetic factors, other environmental factors, or common etiological components. Nonetheless, autoimmune diseases and infections should be considered by clinicians in the treatment of individuals with psychiatric symptoms, since treatment would probably improve the psychiatric symptoms, quality of life, and the survival of the individuals.

A predisposition for allergies predicts subsequent hypertension, dyslipidemia, and diabetes mellitus among patients with schizophrenia or bipolar disorder: a nationwide longitudinal study

BACKGROUND

Previous studies have shown that both severe mental disorders (schizophrenia and bipolar disorder) and atopic diseases were associated with an increased risk of metabolic syndrome. However, the role of atopy/the predisposition for allergies in the development of metabolic syndrome is still unknown among those with severe mental disorders.

METHODS

Using the Taiwan National Health Insurance Research Database, 5826 patients with schizophrenia or bipolar disorder (1908 with a predisposition for allergies and 3918 without) were enrolled between 1998 and 2008. Those who developed hypertension, dyslipidemia, and/or diabetes mellitus were identified during the follow-up to the end of 2011.

RESULTS

A predisposition for allergies increased the risk of developing hypertension (HR: 1.67), dyslipidemia (HR: 1.82), and diabetes mellitus (HR: 1.37) in later life among those with severe mental disorders. A dose-dependent relationship was noted between having more atopic comorbidities and a greater likelihood of hypertension (1 atopic disease: HR: 1.60; ≧ 2 atopic comorbidities: HR: 1.87), dyslipidemia (HR: 1.73; HR: 2.12), and diabetes mellitus (HR: 1.26; HR: 1.69).

CONCLUSION

A predisposition for allergies was an independent risk factor for hypertension, dyslipidemia, and diabetes mellitus among patients with schizophrenia or bipolar disorder. Further studies would be required to elucidate the underlying pathophysiology among atopy, schizophrenia, bipolar disorder, and metabolic syndrome.

Maternal prenatal infection, early susceptibility to illness and adult psychotic experiences: a birth cohort study

BACKGROUND

Existing evidence has established that maternal infection during pregnancy and illness during early life are associated with later schizophrenia. No research has examined how the combination of these prenatal and postnatal exposures is linked to an increased risk to later schizophrenia and psychotic disorders.

METHODS

Participants from the Mater University Study of Pregnancy (MUSP), an Australian based, pre-birth cohort study were examined for lifetime DSM-IV positive psychotic experiences at 21 years by a semi-structured interview. Structural equation modelling was used to derive a general factor of psychotic experiences at age 21. Next, we undertook a number of separate analyses to investigate how prenatal infections and infant illness susceptibility are related to positive psychotic experiences in early adulthood, allowing for tests of moderation and mediation between the two risk factors.

RESULTS

After adjustment for important confounders, infant illness susceptibility was found to play a mediating role in the association between prenatal vaginal infection and later psychotic experiences. Whereby, infant illness susceptibility showed a direct association with psychotic experiences, while prenatal vaginal infection indirectly predicted psychotic experiences via infant illness susceptibility.

CONCLUSION

Our findings suggest that illness susceptibility in early infancy may be central to the relationship between prenatal vaginal infection and later psychotic experiences. Further research is needed to establish the mechanisms that link these prenatal and postnatal exposures with psychotic illness in later life.