Bipolar disorders and schizophrenia: discrete disorders?

Background

With similarities in heritability, neurobiology and symptomatology, the question has been raised whether schizophrenia and bipolar disorder are truly distinctive disorders or belong to a continuum. This narrative review summarizes common and distinctive findings from genetics, neuroimaging, cognition and clinical course that may help to solve this ethiopathogenetic puzzle.

Methods

The authors conducted a literature search for papers listed in PubMed and Google Scholar, using the search terms "schizophrenia" and "bipolar disorder" combined with different terms such as "genes", "neuroimaging studies", "phenomenology differences", "cognition", "epidemiology". Articles were considered for inclusion if they were written in English or Spanish, published as full articles, if they compared subjects with schizophrenia and bipolar disorder, or subjects with either disorder with healthy controls, addressing differences between groups.

Results

Several findings support the hypothesis that schizophrenia and bipolar disorder are discrete disorders, yet some overlapping of findings exists. The evidence for heritability of both SZ and BD is obvious, as well as the environmental impact on individual manifestations of both disorders. Neuroimaging studies support subtle differences between disorders, it appears to be rather a pattern of irregularities than an unequivocally unique finding distinguishing schizophrenia from bipolar disorder. The cognitive profile displays differences between disorders in certain domains, such as premorbid intellectual functioning and executive functions. Finally, the timing and trajectory of cognitive impairment in both disorders also differs.

Conclusion

The question whether SZ and BD belong to a continuum or are separate disorders remains a challenge for further research. Currently, our research tools may be not precise enough to carve out distinctive, unique and undisputable differences between SZ and BD, but current evidence favors separate disorders. Given that differences are subtle, a way to overcome diagnostic uncertainties in the future could be the application of artificial intelligence based on BigData.

Limitations

Despite the detailed search, this article is not a full and complete review of all available studies on the topic. The search and selection of papers was also limited to articles in English and Spanish. Selection of papers and conclusions may be biased by the personal view and clinical experience of the authors.

Neurodevelopmental Disruptions in Children of Preeclamptic Mothers: Pathophysiological Mechanisms and Consequences

Preeclampsia (PE) is a multisystem disorder characterized by elevated blood pressure in the mother, typically occurring after 20 weeks of gestation and posing risks to both maternal and fetal health. PE causes placental changes that can affect the fetus, particularly neurodevelopment. Its key pathophysiological mechanisms encompass hypoxia, vascular and angiogenic dysregulation, inflammation, neuronal and glial alterations, and disruptions in neuronal signaling. Animal models indicate that PE is correlated with neurodevelopmental alterations and cognitive dysfunctions in offspring and in humans, an association between PE and conditions such as cerebral palsy, autism spectrum disorder, attention deficit hyperactivity disorder, and sexual dimorphism has been observed. Considering the relevance for mothers and children, we conducted a narrative literature review to describe the relationships between the pathophysiological mechanisms behind neurodevelopmental alterations in the offspring of PE mothers, along with their potential consequences. Furthermore, we emphasize aspects pertinent to the prevention/treatment of PE in pregnant mothers and alterations observed in their offspring. The present narrative review offers a current, complete, and exhaustive analysis of (i) the pathophysiological mechanisms that can affect neurodevelopment in the children of PE mothers, (ii) the relationship between PE and neurological alterations in offspring, and (iii) the prevention/treatment of PE.

The prevalence and risk of developing major depression among individuals with subthreshold depression in the general population

BACKGROUND

Subthreshold depression could be a significant precursor to and a risk factor for major depression. However, reliable estimates of the prevalence and its contribution to developing major depression under different terminologies depicting subthreshold depression have to be established.

METHODS

By searching PubMed and Web of Science using predefined inclusion criteria, we included 1 129 969 individuals from 113 studies conducted. The prevalence estimates were calculated using the random effect model. The incidence risk ratio (IRR) was estimated by measuring the ratio of individuals with subthreshold depression who developed major depression compared to that of non-depressed individuals from 19 studies (88, 882 individuals).

RESULTS

No significant difference in the prevalence among the different terminologies depicting subthreshold depression (Q = 1.96, p = 0.5801) was found. By pooling the prevalence estimates of subthreshold depression in 113 studies, we obtained a summary prevalence of 11.02% [95% confidence interval (CI) 9.78-12.33%]. The youth group had the highest prevalence (14.17%, 95% CI 8.82-20.55%), followed by the elderly group (12.95%, 95% CI 11.41-14.58%) and the adult group (8.92%, 95% CI 7.51-10.45%). Further analysis of 19 studies' incidence rates showed individuals with subthreshold depression had an increased risk of developing major depression (IRR = 2.95, 95% CI 2.33-3.73), and the term minor depression showed the highest IRR compared with other terms (IRR = 3.97, 95% CI 3.17-4.96).

CONCLUSIONS

Depression could be a spectrum disorder, with subthreshold depression being a significant precursor to and a risk factor for major depression. Proactive management of subthreshold depression could be effective for managing the increasing prevalence of major depression.

Inclusion body myositis: evolving concepts

PURPOSE OF REVIEW

To discuss recent developments in our understanding of epidemiology, diagnostics, biomarkers, pathology, pathogenesis, outcome measures, and therapeutics in inclusion body myositis (IBM).

RECENT FINDINGS

Recent epidemiology data confirms a relatively higher prevalence in the population aged above 50 years and the reduced life expectancy. Association with cancer and other systemic disorders is better defined. The role of magnetic resonance imaging (MRI) and ultrasound in diagnosis as well as in following disease progression has been elucidated. There are new blood and imaging biomarkers that show tremendous promise for diagnosis and as outcome measures in therapeutic trials. Improved understanding of the pathogenesis of the disease will lead to better therapeutic interventions, but also highlights the importance to have sensitive and responsive outcome measures that accurately quantitate change.

SUMMARY

There are exciting new developments in our understanding of IBM which should lead to improved management and therapeutic options.

Neuro-Behçet Disease, Neuro-Sweet Disease, and Spectrum Disorders

Behçet disease and its related disorder, Sweet disease, are multifactorial disorders whose susceptibility loci have been identified in the genes of various immunological factors aside from human leukocyte antigens. The neurological involvement of these diseases, including encephalitis, myelitis, and meningitis, referred to as neuro-Behçet disease (NBD) and neuro-Sweet disease (NSD) respectively, is sometimes difficult to diagnose, especially when the characteristic mucocutaneous symptoms do not precede neurological symptoms or when characteristics of both diseases are present in a single patient. NBD and NSD constitute a spectrum of diseases that are differentiated according to the combination of risk factors, including the genetic background. Encephalitis, myelitis, and meningitis similar to NBD or NSD can be diagnosed as spectrum disorders, even if the characteristic mucocutaneous symptoms fail to be detected. Understanding these conditions as a disease spectrum may help elucidate the disease pathogenesis and assist in the development of therapeutic agents.

Ionic Channels as Potential Targets for the Treatment of Autism Spectrum Disorder: A Review

Autism spectrum disorder (ASD) is a neurological condition that directly affects brain functions and can culminate in delayed intellectual development, problems in verbal communication, difficulties in social interaction, and stereotyped behaviors. Its etiology reveals a genetic basis that can be strongly influenced by socio-environmental factors. Ion channels controlled by ligand voltage-activated calcium, sodium, and potassium channels may play important roles in modulating sensory and cognitive responses, and their dysfunctions may be closely associated with neurodevelopmental disorders such as ASD. This is due to ionic flow, which is of paramount importance to maintaining physiological conditions in the central nervous system and triggers action potentials, gene expression, and cell signaling. However, since ASD is a multifactorial disease, treatment is directed only to secondary symptoms. Therefore, this research aims to gather evidence concerning the principal pathophysiological mechanisms involving ion channels in order to recognize their importance as therapeutic targets for the treatment of central and secondary ASD symptoms.

Diagnosis of Auditory Neuropathy Spectrum Disorder in the Neonatal Intensive Care Unit Population

OBJECTIVE

To determine the incidence of auditory neuropathy spectrum disorder (ANSD) and its risk factors among the neonatal intensive care unit (NICU) population from 2009 to 2018 in the Pediatric Health Information System database.

STUDY DESIGN

Retrospective national database review.

SETTING

Population-based study.

METHODS

The Pediatric Health Information System database was queried to identify patients ≤18 years old with NICU admission and ANSD diagnosis. Patient demographics, jaundice diagnosis, use of mechanical ventilation, extracorporeal membrane oxygenation, furosemide, and/or aminoglycosides were extracted. Multivariable linear regression was used to assess trends in incidence. Chi-square analysis was used to assess differences between patients with and without ANSD. Logistic regression was used to assess factors associated with ANSD.

RESULTS

From 2009 to 2018, there was an increase in (1) NICU admissions from 14,079 to 24,851 (P < .001), (2) total ANSD diagnoses from 92 to 1847 (P = .001), and (3) annual total number of patients with ANSD and NICU admission increased from 4 to 16 (P = .005). There was strong correlation between the increases in total number of NICU admissions and total ANSD diagnoses over time (R = 0.76). The average ANSD incidence was 0.052% with no statistically significant change over 10 years. When compared with all NICU admissions, children with ANSD had a higher association with use of furosemide (P < .001) and ventilator (P < .001).

CONCLUSION

Despite a statistically significant increase in NICU admissions and total ANSD diagnosis, the incidence of ANSD in the NICU population has not increased from 2009 to 2018. Furosemide and mechanical ventilator use were associated with increased likelihood of ANSD.

The Impact of a Novel Mimicry Task for Increasing Emotion Recognition in Adults with Autism Spectrum Disorder and Alexithymia: Protocol for a Randomized Controlled Trial

Background

Impaired facial emotion expression recognition (FEER) has typically been considered a correlate of autism spectrum disorder (ASD). Now, the alexithymia hypothesis is suggesting that this emotion processing problem is instead related to alexithymia, which frequently co-occurs with ASD. By combining predictive coding theories of ASD and simulation theories of emotion recognition, it is suggested that facial mimicry may improve the training of FEER in ASD and alexithymia.

Objective

This study aims to evaluate a novel mimicry task to improve FEER in adults with and without ASD and alexithymia. Additionally, this study will aim to determine the contributions of alexithymia and ASD to FEER ability and assess which of these 2 populations benefit from this training task.

Methods

Recruitment will primarily take place through an ASD community group with emphasis put on snowball recruiting. Included will be 64 consenting adults equally divided between participants without an ASD and participants with an ASD. Participants will be screened online using the Kessler Psychological Distress Scale (K-10; cut-off score of 22), Autism Spectrum Quotient (AQ-10), and Toronto Alexithymia Scale (TAS-20) followed by a clinical interview with a provisional psychologist at the Federation University psychology clinic. The clinical interview will include assessment of ability, anxiety, and depression as well as discussion of past ASD diagnosis and confirmatory administration of the Autism Mental Status Exam (AMSE). Following the clinical interview, the participant will complete the Bermond-Vorst Alexithymia Questionnaire (BVAQ) and then undertake a baseline assessment of FEER. Consenting participants will then be assigned using a permuted blocked randomization method into either the control task condition or the mimicry task condition. A brief measure of satisfaction of the task and a debriefing session will conclude the study.

Results

The study has Federation University Human Research Ethics Committee approval and is registered with the Australian New Zealand Clinical Trials. Participant recruitment is predicted to begin in the third quarter of 2021.

Conclusions

This study will be the first to evaluate the use of a novel facial mimicry task condition to increase FEER in adults with ASD and alexithymia. If efficacious, this task could prove useful as a cost-effective adjunct intervention that could be used at home and thus remove barriers to entry. This study will also explore the unique effectiveness of this task in people without an ASD, with an ASD, and with alexithymia.

Trial Registration

Australian New Zealand Clinical Trial Registry ACTRN12619000705189p; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=377455

International Registered Report Identifier (IRRID)

PRR1-10.2196/24543

One-and-a-half syndrome with its spectrum disorders

One-and-a-half syndrome is a syndrome characterized by horizontal movement disorders of the eyeballs, which was first reported and named by Fisher in 1967. It presents a combination of ipsilateral conjugate horizontal gaze palsy (one) and ipsilateral internuclear ophthalmoplegia (INO) (a half). On the basis of the one-and-a-half syndrome, there are a series of related rare syndromes called the one-and-a-half syndrome spectrum disorders. This article reviews rare cases of one-and-a-half syndrome spectrum disorder, describes the clinical and pathological features of different syndromes, and summarizes their nomenclature.

Schizophrenia: family studies and treatment of spectrum disorders

A substantial part of the contribution of genetic studies to the treatment of schizophrenia involves its emphasis on reliable and valid diagnoses. One consequence of this focus is the recognition that schizophrenic illness is broader than the diagnostic entity of schizophrenia itself, and instead consists of a "spectrum" of related disorders. Because some of the symptoms in these disorders differ from each other, they provide an opportunity to determine which ones reflect a common etiology. To the extent that such symptoms are identifiable, they may provide a foundation for treatment and even prevention strategies. In this paper, we focus on a clinical condition - "schizotaxia" - that may reflect the liability for schizophrenia. To characterize the nature and extent of this proposed syndrome, we will review results from family studies in our laboratory, and consider conceptual foundations and criteria for assessment. A more general consideration of treatment strategies for schizophrenia spectrum disorders follows, along with suggestions for future research. Our initial attempts to treat and validate schizotaxia are encouraging, and raise the possibility that early treatment might eventually prevent or attenuate the development of other, more severe disorders in the schizophrenia spectrum, including schizophrenia itself.