Hot Topics in Schizophrenia Research - Part I

A special issue of Journal of Clinical Medicine (ISSN 2077-0383). This special issue belongs to the section "Mental Health".

Deadline for manuscript submissions: closed (31 May 2021) | Viewed by 52357

Special Issue Editors

Department of Psychiatry, University Hospital Frankfurt, Frankfurt, Germany
Interests: clinical psychiatry; mental illness; psychopathology; psychotherapeutic processes
Department of Psychiatry, Division of Consultation Psychiatry and Neuroscience, Wroclaw Medical University, 50-367 Wroclaw, Poland.
Interests: neuroscience; psychopathology; memory; neuroimaging; cognitive neuroscience; mental illness
Department of Psychiatry, Pomeranian Medical University in Szczecin, 71-457 Szczecin, Poland
Interests: genetics of addictions; depression; anxiety disorders; attention deficit hyperactivity disorder (ADHD); pharmacogenetics of schizophrenia

Special Issue Information

Dear Colleagues,

Schizophrenia represents neurodevelopmental disorders and is ranked among most substantial causes of disability worldwide. It is characterized by multidimensional psychopathology that includes positive, negative and mood symptoms as well as cognitive impairment. The etiology of schizophrenia is even more complex with the involvement of several genetic and environmental factors. Although heritability rates of schizophrenia exceed 80% in twin studies, rare variants with large effect size estimates can be detected in the minority of patients with schizophrenia. Similarly, several environmental exposures have been associated with schizophrenia risk and include, i.e., early-life infections, obstetric complications, psychosocial stress and substance use. However, none of them is neither necessary nor sufficient for the development of schizophrenia. Antipsychotic drugs are still perceived as the main treatment of schizophrenia. Although they largely improve a severity of positive symptoms, their efficacy with respect to negative symptomatology and cognitive deficits is insufficient. Additionally, adverse metabolic effects of antipsychotics contribute to cardiovascular comorbidity that is highly prevalent in patients with schizophrenia. The aim of this special issue is to provide a forum of review papers and original studies that address hot topics related to the etiology and emerging treatments of schizophrenia-spectrum disorders.

Dr. Andreas Reif
Dr. Blazej Misiak
Dr. Jerzy Samochowiec
Guest Editors

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Keywords

  • Psychosis
  • Severe mental illness
  • Psychiatry
  • Neuropsychopharmacology
  • Antipsychotics

Published Papers (16 papers)

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Research

Jump to: Review

14 pages, 270 KiB  
Article
Acceptance and Commitment Therapy versus Social Support for Smoking Cessation for People with Schizophrenia: A Randomised Controlled Trial
by Yim-Wah Mak, Alice-Yuen Loke and Doris Y. P. Leung
J. Clin. Med. 2021, 10(19), 4304; https://0-doi-org.brum.beds.ac.uk/10.3390/jcm10194304 - 22 Sep 2021
Cited by 7 | Viewed by 2321
Abstract
Smoking is prevalent among people with schizophrenia. It has been found that Acceptance and commitment therapy (ACT) is effective for treating psychotic symptoms and addictive behaviours, but the therapy has not been modified to help individuals with schizophrenia to quit smoking. A randomised [...] Read more.
Smoking is prevalent among people with schizophrenia. It has been found that Acceptance and commitment therapy (ACT) is effective for treating psychotic symptoms and addictive behaviours, but the therapy has not been modified to help individuals with schizophrenia to quit smoking. A randomised controlled trial was conducted with the objective of comparing a 10-week, individual, face-to-face ACT programme (n = 65) to a social support programme on smoking cessation, experiential avoidance, and emotion-regulation strategies among people with schizophrenia who smoke (n = 65). The primary outcome was self-reported smoking abstinence for 7 days at 6 months after the start of the intervention. Secondary outcomes were self-reported and biochemically validated quit rates post-intervention. The Avoidance and Inflexibility Scale (AIS), Acceptance and Action Questionnaire II (AAQII), and Emotion Regulation Questionnaire (ERQ) were employed. The self-reported quit rates in the ACT group were higher than in the social support group, although no significant differences were found (6 months: 12.3% vs. 7.7%, p = 0.56, 12 months: 10.8% vs. 7.7%, p = 0.76). We found significantly greater improvements in smoking-specific and ACT-specific experiential avoidance and less reliance on emotion regulation strategies in the ACT group at some time points. Overall, ACT is better than social support at enhancing experiential avoidance and reducing reliance on emotion regulation strategies in adults with schizophrenia who smoke. However, ACT did not produce a much better result than social support in helping them to completely quit smoking. Full article
(This article belongs to the Special Issue Hot Topics in Schizophrenia Research - Part I)
16 pages, 1249 KiB  
Article
Relationship of Corpus Callosum Integrity with Working Memory, Planning, and Speed of Processing in Patients with First-Episode and Chronic Schizophrenia
by Ernest Tyburski, Piotr Podwalski, Katarzyna Waszczuk, Katarzyna Rek-Owodziń, Monika Mak, Piotr Plichta, Maksymilian Bielecki, Krzysztof Rudkowski, Michał Szelepajło, Jolanta Kucharska-Mazur, Wojciech Andrusewicz, Błażej Misiak, Magdalena Kerestey, Adrianna Bober, Krzysztof Wietrzyński, Anna Michalczyk, Magdalena Więdłocha, Piotr Marcinowicz, Jerzy Samochowiec and Leszek Sagan
J. Clin. Med. 2021, 10(14), 3158; https://0-doi-org.brum.beds.ac.uk/10.3390/jcm10143158 - 17 Jul 2021
Cited by 5 | Viewed by 2071
Abstract
There is a paucity of reports examining the relationship between the integrity of the corpus callosum (CC) and different aspects of cognitive functioning in patients with first-episode (FES) and chronic schizophrenia (CS) simultaneously; furthermore, what results exist are inconclusive. We used diffusion tensor [...] Read more.
There is a paucity of reports examining the relationship between the integrity of the corpus callosum (CC) and different aspects of cognitive functioning in patients with first-episode (FES) and chronic schizophrenia (CS) simultaneously; furthermore, what results exist are inconclusive. We used diffusion tensor imaging tractography to investigate differences in integrity in five regions of the CC between FES, CS, and healthy controls (HC). Additionally, we analyzed correlations between these regions’ integrity and working memory, planning, and speed of processing. Eighteen patients with FES, 55 patients with CS, and 30 HC took part in the study. We assessed cognitive functions with four tasks from Measurement and Treatment Research to Improve Cognition in Schizophrenia. Patients with CS showed lower fractional anisotropy (FA) in Region 5 (statistical trend) and higher mean diffusivity (MD) in Regions 4 and 5 than HC, and patients with FES had higher MD in Region 3 (statistical trend) than HC. Both clinical groups performed worse on working memory and speed of processing tasks than HC, and patients with CS scored worse than HC on independent planning, and worse than FES and HC on dependent planning. Moreover, in patients with CS, MD in Region 3 was correlated with verbal working memory. Our results suggest that patients with FES and CS are characterized by impaired integrity of the middle and posterior CC, respectively. We confirmed that both clinical groups have cognitive impairments. Moreover, the integrity of the middle CC may influence planning in patients with CS. Full article
(This article belongs to the Special Issue Hot Topics in Schizophrenia Research - Part I)
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11 pages, 257 KiB  
Article
Can Intergroup Contact in Virtual Reality (VR) Reduce Stigmatization Against People with Schizophrenia?
by Daniela Stelzmann, Roland Toth and David Schieferdecker
J. Clin. Med. 2021, 10(13), 2961; https://0-doi-org.brum.beds.ac.uk/10.3390/jcm10132961 - 30 Jun 2021
Cited by 17 | Viewed by 3661
Abstract
People with mental disorders such as schizophrenia do not only suffer from the symptoms of their disorders but also from the stigma attached to it. Although direct intergroup contact is an effective tool to reduce stigmatization, it is rare in real life and [...] Read more.
People with mental disorders such as schizophrenia do not only suffer from the symptoms of their disorders but also from the stigma attached to it. Although direct intergroup contact is an effective tool to reduce stigmatization, it is rare in real life and costly to be established in interventions, and the success of traditional media campaigns is debatable. We propose Virtual Reality (VR) as a low-threshold alternative for establishing contact since it involves less barriers for affected and unaffected persons. In a 2 + 1 experiment (n = 114), we compared the effects of encounters with a person with schizophrenia through a VR video with contact through a regular video and no contact at all on anxiety, empathy, social proximity, and benevolence towards people with schizophrenia. We found that contact via VR reduced stigmatization only for participants who liked the person encountered. Our data suggest that it is crucial how participants evaluate the person that they encounter and that stronger perception of spatial presence during reception plays an important role, too. Therefore, we discussvarious boundary conditions that need to be considered in VR interventions and future research on destigmatization towards mental disorders, especially schizophrenia. Full article
(This article belongs to the Special Issue Hot Topics in Schizophrenia Research - Part I)
10 pages, 913 KiB  
Article
Being Born in Winter–Spring and at Around the Time of an Influenza Pandemic Are Risk Factors for the Development of Schizophrenia: The Apna Study in Navarre, Spain
by Miguel A. Alvarez-Mon, Sara Guillen-Aguinaga, Victor Pereira-Sanchez, Luc Onambele, Moad J. Al-Rahamneh, Antonio Brugos-Larumbe, Francisco Guillen-Grima and Felipe Ortuño
J. Clin. Med. 2021, 10(13), 2859; https://0-doi-org.brum.beds.ac.uk/10.3390/jcm10132859 - 28 Jun 2021
Cited by 5 | Viewed by 2365
Abstract
Background: We analyzed the relationship between the prevalence of schizophrenia and the season of birth and gestation during a period of an influenza pandemic. Methods: Cross-sectional analysis of a prospective population-based cohort of 470,942 adults. We fitted multivariant logistic regression models to determine [...] Read more.
Background: We analyzed the relationship between the prevalence of schizophrenia and the season of birth and gestation during a period of an influenza pandemic. Methods: Cross-sectional analysis of a prospective population-based cohort of 470,942 adults. We fitted multivariant logistic regression models to determine whether the season of birth and birth in an influenza-pandemic year (1957, 1968, 1977) was associated with schizophrenia. Results: 2077 subjects had been diagnosed with schizophrenia. Logistic regression identified a significantly greater prevalence of schizophrenia in men than in women (OR = 1.516, CI 95% = 1.388–1.665); in those born in the winter or spring than in those born in the summer or autumn (OR = 1.112, CI 95% = 1.020–1.212); and in those born in a period of an influenza pandemic (OR = 1.335, CI 95% = 1.199–1.486). The increase in risk was also significant when each influenza pandemic year was analyzed separately. However, neither month of birth nor season of birth, when each of the four were studied individually, were associated with a statistically significant increase in that risk. Conclusions: The winter–spring period and the influenza pandemics are independent risk factors for developing schizophrenia. This study contradicts many previous studies and thus revitalizes a locked debate in understanding the neurodevelopmental hypothesis of this disorder. Full article
(This article belongs to the Special Issue Hot Topics in Schizophrenia Research - Part I)
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17 pages, 1472 KiB  
Article
White Matter Integrity of the Corpus Callosum and Psychopathological Dimensions in Deficit and Non-Deficit Schizophrenia Patients
by Piotr Podwalski, Ernest Tyburski, Krzysztof Szczygieł, Katarzyna Waszczuk, Katarzyna Rek-Owodziń, Monika Mak, Piotr Plichta, Maksymilian Bielecki, Krzysztof Rudkowski, Jolanta Kucharska-Mazur, Wojciech Andrusewicz, Błażej Misiak, Agata Szulc, Anna Michalczyk, Sylwia Michałowska, Leszek Sagan and Jerzy Samochowiec
J. Clin. Med. 2021, 10(11), 2225; https://0-doi-org.brum.beds.ac.uk/10.3390/jcm10112225 - 21 May 2021
Cited by 11 | Viewed by 2184
Abstract
Deficit syndrome (DS) is a subtype of schizophrenia characterized by primary persistent negative symptoms. The corpus callosum (CC) appears to be related to psychopathology in schizophrenia. This study assessed white matter integrity in the CC using diffusion tensor imaging (DTI) in deficit and [...] Read more.
Deficit syndrome (DS) is a subtype of schizophrenia characterized by primary persistent negative symptoms. The corpus callosum (CC) appears to be related to psychopathology in schizophrenia. This study assessed white matter integrity in the CC using diffusion tensor imaging (DTI) in deficit and non-deficit schizophrenia (NDS) patients. We also investigated the psychopathological dimensions of schizophrenia and their relationship to CC integrity. Fifteen DS patients, 40 NDS patients, and 30 healthy controls (HC) underwent psychiatric evaluation and neuroimaging. We divided the CC into five regions and assessed their fractional anisotropy (FA) and mean diffusivity (MD). Psychopathology was assessed with the Positive and Negative Syndrome Scale. DS patients had lower FA than NDS patients and HC, and higher MD in Region 5 of the CC than did HC. NDS patients had higher MD in Region 4 of the CC. The patient groups differed in terms of negative symptoms. After differentiating clinical groups and HC, no significant correlations were observed between DTI measures and psychopathological symptoms. Our results suggest that DS and NDS are characterized by minor impairments of the posterior CC. We confirmed that DS patients have greater negative psychopathology than NDS patients. Our results are preliminary, and further studies are needed. Full article
(This article belongs to the Special Issue Hot Topics in Schizophrenia Research - Part I)
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8 pages, 262 KiB  
Article
Paliperidone Palmitate Every Three Months (PP3M) 2-Year Treatment Compliance, Effectiveness and Satisfaction Compared with Paliperidone Palmitate-Monthly (PP1M) in People with Severe Schizophrenia
by Juan J. Fernández-Miranda, Silvia Díaz-Fernández, Domenico De Berardis and Francisco López-Muñoz
J. Clin. Med. 2021, 10(7), 1408; https://0-doi-org.brum.beds.ac.uk/10.3390/jcm10071408 - 01 Apr 2021
Cited by 18 | Viewed by 2392
Abstract
Paliperidone palmitate every three months (PP3M) is expected to facilitate patient’s treatment compliance and satisfaction. The objective here was to compare PP3M treatment compliance and satisfaction, effectiveness and tolerability, with paliperidone palmitate-monthly (PP1M) in patients with severe schizophrenia. A 24-month prospective, open-label study [...] Read more.
Paliperidone palmitate every three months (PP3M) is expected to facilitate patient’s treatment compliance and satisfaction. The objective here was to compare PP3M treatment compliance and satisfaction, effectiveness and tolerability, with paliperidone palmitate-monthly (PP1M) in patients with severe schizophrenia. A 24-month prospective, open-label study of patients with severe schizophrenia treated with PP3M after at least 2 years of stabilization with PP1M (n = 84) was carried out. Treatment satisfaction was assessed with the Treatment Satisfaction Questionnaire for Medication (TSQM) and with a Visual Analogue Scale (VAS). Effectiveness was measured with psychiatric hospital admissions and the Clinical Global Impression-Severity (CGI-S) scale. Tolerability assessments included laboratory tests, weight and adverse effects. Reasons for treatment discontinuation were recorded. CGI-S significantly improved after 24 months. Three patients changed back to PP1M due to adverse effects, and four were hospitalized. There were neither abandoning nor significant changes in weight or biological parameters, and lower incidence of side effects, with PP3M treatment. TSQM and VAS scales increased. No differences were found related to doses. Apart from somewhat improvement in treatment adherence, effectiveness, and tolerability, patients with severe schizophrenia lengthy treated with PP1M showed more satisfaction with PP3M, even those who needed high doses to get clinical stabilization. Full article
(This article belongs to the Special Issue Hot Topics in Schizophrenia Research - Part I)
11 pages, 263 KiB  
Article
The Association between Lifestyle Choices and Schizophrenia Symptoms
by Sylwia Kalinowska, Beata Trześniowska-Drukała, Karolina Kłoda, Krzysztof Safranow, Błażej Misiak, Agnieszka Cyran and Jerzy Samochowiec
J. Clin. Med. 2021, 10(1), 165; https://0-doi-org.brum.beds.ac.uk/10.3390/jcm10010165 - 05 Jan 2021
Cited by 14 | Viewed by 4633
Abstract
Due to poor eating habits, insufficient physical activity, and nicotine use, schizophrenia patients are at increased risk of lifestyle diseases. Factors contributing to unhealthy behaviors include lower socioeconomic status and level of education as well as social isolation. Schizophrenia manifestations such as amotivation, [...] Read more.
Due to poor eating habits, insufficient physical activity, and nicotine use, schizophrenia patients are at increased risk of lifestyle diseases. Factors contributing to unhealthy behaviors include lower socioeconomic status and level of education as well as social isolation. Schizophrenia manifestations such as amotivation, apathy, and cognitive deficits can further hinder development of proper health habits. The aim of this study was to assess the possible association between lifestyle-related choices and schizophrenia symptoms severity. This observational study enrolled 106 patients with schizophrenia (42 Males/64 Females), 18–69 years (mean: 41.89 ± 9.7 years). Mean duration of schizophrenia was 14.61 ± 9.7 years. Multiple significant correlations were found between patients’ lifestyle and their biochemical laboratory parameters (lipid profile and fasting glucose). Most importantly, a significant link emerged between presented habits and schizophrenia symptom severity. There were also significant gender differences in the intake of sweets and sweet beverages. Quite unexpectedly, a behavioral shift towards more healthy lifestyle choices was observed after completion of questionnaires on lifestyle and health habits. There are clear benefits to systematic provision of educational interventions concerning physical activity and proper eating habits to schizophrenia patients. These simple preventive measures could significantly improve both mental and physical health outcomes in schizophrenia patient populations. Full article
(This article belongs to the Special Issue Hot Topics in Schizophrenia Research - Part I)
10 pages, 502 KiB  
Article
Metabolic Dysregulation and Psychosocial Stress in Patients with Schizophrenia Spectrum Disorders: A Case-Control Study
by Błażej Misiak, Patryk Piotrowski, Jan Aleksander Beszłej, Sylwia Kalinowska, Magdalena Chęć and Jerzy Samochowiec
J. Clin. Med. 2020, 9(12), 3822; https://0-doi-org.brum.beds.ac.uk/10.3390/jcm9123822 - 26 Nov 2020
Cited by 8 | Viewed by 2011
Abstract
Patients with schizophrenia spectrum disorders have a reduced life expectancy, which is largely the consequence of a high co-occurrence of cardiovascular diseases. To date, several intrinsic and environmental factors underlying this phenomenon have been found. However, the association with psychosocial stress has not [...] Read more.
Patients with schizophrenia spectrum disorders have a reduced life expectancy, which is largely the consequence of a high co-occurrence of cardiovascular diseases. To date, several intrinsic and environmental factors underlying this phenomenon have been found. However, the association with psychosocial stress has not been extensively addressed. In this study, we tested the relationship between a history of adverse childhood experiences (ACEs), lifetime stressors, perceived stress and metabolic parameters in patients with schizophrenia spectrum disorders and in healthy controls. The participants included 85 inpatients with schizophrenia spectrum disorders and 56 healthy controls. Serum levels of glucose, insulin, low- and high-density lipoproteins (LDL and HDL), triglycerides, total cholesterol and high-sensitivity C-reactive protein (hsCRP) were determined. After adjustment for potential confounding factors, patients had significantly higher levels of glucose (F = 4.856, p = 0.030), triglycerides (F = 4.720, p = 0.032) and hsCRP (F = 7.499, p = 0.007) as well as significantly lower levels of HDL (F = 5.300, p = 0.023) compared to healthy controls. There were also significant effects of interactions between diagnosis and a history of ACEs on the levels of insulin (F = 4.497, p = 0.036) and homeostatic model assessment of insulin resistance (HOMA-IR) (F = 3.987, p = 0.048). More specifically, the levels of insulin and HOMA-IR were significantly higher in the subgroup of patients with schizophrenia spectrum disorders and a positive history of ACEs compared to other subgroups of participants. No significant associations between lifetime stressors and perceived stress with metabolic parameters were found. Our findings indicate that a history of ACEs might be associated with insulin resistance in patients with schizophrenia spectrum disorders. Therapeutic strategies targeting early-life stress should be considered with early interventions that aim to manage cardiometabolic comorbidity in patients with schizophrenia spectrum disorders. Full article
(This article belongs to the Special Issue Hot Topics in Schizophrenia Research - Part I)
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15 pages, 863 KiB  
Article
Adverse Childhood Experiences and Methylation of the FKBP5 Gene in Patients with Psychotic Disorders
by Błażej Misiak, Paweł Karpiński, Elżbieta Szmida, Tomasz Grąźlewski, Marcin Jabłoński, Katarzyna Cyranka, Joanna Rymaszewska, Patryk Piotrowski, Kamila Kotowicz and Dorota Frydecka
J. Clin. Med. 2020, 9(12), 3792; https://0-doi-org.brum.beds.ac.uk/10.3390/jcm9123792 - 24 Nov 2020
Cited by 20 | Viewed by 2464
Abstract
Altered methylation of the FKBP5 gene has been observed in various mental disorders and attributed to the effects of adverse childhood experiences (ACEs). However, the level of FKBP5 methylation has not been investigated in patients with psychotic disorders. Therefore, in this study we [...] Read more.
Altered methylation of the FKBP5 gene has been observed in various mental disorders and attributed to the effects of adverse childhood experiences (ACEs). However, the level of FKBP5 methylation has not been investigated in patients with psychotic disorders. Therefore, in this study we aimed to determine the FKBP5 methylation in patients with psychosis and controls, taking into account the effects of ACEs. Participants were 85 patients with psychotic disorders, including first-episode psychosis (FEP) patients and acutely relapsed schizophrenia (SCZ-AR) patients, as well as 56 controls. The level of four CpG sites at the FKBP5 gene was determined in the peripheral blood leukocytes using pyrosequencing. After controlling for potential confounding factors, the level of FKBP5 methylation at one out of four tested CpG sites was significantly lower in FEP patients compared to other groups of participants. Significant main effects of parental antipathy and sexual abuse on the level of FKBP5 methylation were observed at the differentially methylated CpG site. Participants reporting this category of ACEs had significantly lower levels of FKBP5 methylation at this CpG site. Lower levels of FKBP5 methylation were associated with better cognitive performance and higher functional capacity in patients with psychosis. In controls, lower methylation of FKBP5 was related to worse performance of immediate memory and language skills. Our findings suggest that hypomethylation of the FKBP5 appears at early stages of psychosis and might be associated with a history of ACEs as well as less severe clinical manifestation. Full article
(This article belongs to the Special Issue Hot Topics in Schizophrenia Research - Part I)
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13 pages, 973 KiB  
Article
The Differences between Gluten Sensitivity, Intestinal Biomarkers and Immune Biomarkers in Patients with First-Episode and Chronic Schizophrenia
by Michał Dzikowski, Dariusz Juchnowicz, Izabela Dzikowska, Joanna Rog, Michał Próchnicki, Małgorzata Kozioł and Hanna Karakula-Juchnowicz
J. Clin. Med. 2020, 9(11), 3707; https://0-doi-org.brum.beds.ac.uk/10.3390/jcm9113707 - 18 Nov 2020
Cited by 11 | Viewed by 3341
Abstract
Schizophrenia is a heterogeneous disorder without a fully elucidated etiology and mechanisms. One likely explanation for the development of schizophrenia is low-grade inflammation, possibly caused by processes in the gastrointestinal tract related to gluten sensitivity. The aims of this study were to: (1) [...] Read more.
Schizophrenia is a heterogeneous disorder without a fully elucidated etiology and mechanisms. One likely explanation for the development of schizophrenia is low-grade inflammation, possibly caused by processes in the gastrointestinal tract related to gluten sensitivity. The aims of this study were to: (1) compare levels of markers of gluten sensitivity, inflammation and gut permeability, and (2) determine associations between gluten sensitivity, inflammation, and intestinal permeability in patients with first-episode/chronic (FS/CS) schizophrenia and healthy individuals (HC). The total sample comprised 162 individuals (52 FS; 50 CS, and 60 HC). The examination included clinical variables, nutritional assessment, and serum concentrations of: high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), soluble CD14 (sCD14), anti-Saccharomyces cerevisiae antibody (ASCA), antigliadin antibodies (AGA) IgA/IgG, antibodies against tissue transglutaminase 2 (anti-tTG) IgA, anti-deamidated gliadin peptides (anti-DGP) IgG. A significant difference between groups was found in sCD14, ASCA, hs-CRP, IL-6 and AGA IgA levels. AGA IgG/IgA levels were higher in the FS (11.54%; 30.77%) and CS (26%; 20%) groups compared to HC. The association between intestinal permeability and inflammation in the schizophrenic patients only was noted. The risk for developing schizophrenia was odds ratio (OR) = 4.35 (95% confidence interval (CI 1.23–15.39) for AGA IgA and 3.08 (95% CI 1.19–7.99) for positive AGA IgG. Inflammation and food hypersensitivity reactions initiated by increased intestinal permeability may contribute to the pathophysiology of schizophrenia. The immune response to gluten in FS differs from that found in CS. Full article
(This article belongs to the Special Issue Hot Topics in Schizophrenia Research - Part I)
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Review

Jump to: Research

35 pages, 1040 KiB  
Review
Neural Correlates of Aberrant Salience and Source Monitoring in Schizophrenia and At-Risk Mental States—A Systematic Review of fMRI Studies
by Joachim Kowalski, Adrianna Aleksandrowicz, Małgorzata Dąbkowska and Łukasz Gawęda
J. Clin. Med. 2021, 10(18), 4126; https://0-doi-org.brum.beds.ac.uk/10.3390/jcm10184126 - 13 Sep 2021
Cited by 15 | Viewed by 3129
Abstract
Cognitive biases are an important factor contributing to the development and symptom severity of psychosis. Despite the fact that various cognitive biases are contributing to psychosis, they are rarely investigated together. In the current systematic review, we aimed at investigating specific and shared [...] Read more.
Cognitive biases are an important factor contributing to the development and symptom severity of psychosis. Despite the fact that various cognitive biases are contributing to psychosis, they are rarely investigated together. In the current systematic review, we aimed at investigating specific and shared functional neural correlates of two important cognitive biases: aberrant salience and source monitoring. We conducted a systematic search of fMRI studies of said cognitive biases. Eight studies on aberrant salience and eleven studies on source monitoring were included in the review. We critically discussed behavioural and neuroimaging findings concerning cognitive biases. Various brain regions are associated with aberrant salience and source monitoring in individuals with schizophrenia and the risk of psychosis. The ventral striatum and insula contribute to aberrant salience. The medial prefrontal cortex, superior and middle temporal gyrus contribute to source monitoring. The anterior cingulate cortex and hippocampus contribute to both cognitive biases, constituting a neural overlap. Our review indicates that aberrant salience and source monitoring may share neural mechanisms, suggesting their joint role in producing disrupted external attributions of perceptual and cognitive experiences, thus elucidating their role in positive symptoms of psychosis. Account bridging mechanisms of these two biases is discussed. Further studies are warranted. Full article
(This article belongs to the Special Issue Hot Topics in Schizophrenia Research - Part I)
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24 pages, 619 KiB  
Review
Disturbances in White Matter Integrity in the Ultra-High-Risk Psychosis State—A Systematic Review
by Katarzyna Waszczuk, Katarzyna Rek-Owodziń, Ernest Tyburski, Monika Mak, Błażej Misiak and Jerzy Samochowiec
J. Clin. Med. 2021, 10(11), 2515; https://0-doi-org.brum.beds.ac.uk/10.3390/jcm10112515 - 06 Jun 2021
Cited by 15 | Viewed by 2482
Abstract
Schizophrenia is a severe and disabling mental illness whose etiology still remains unclear. The available literature indicates that there exist white matter (WM) abnormalities in people with schizophrenia spectrum disorders. Recent developments in modern neuroimaging methods have enabled the identification of the structure, [...] Read more.
Schizophrenia is a severe and disabling mental illness whose etiology still remains unclear. The available literature indicates that there exist white matter (WM) abnormalities in people with schizophrenia spectrum disorders. Recent developments in modern neuroimaging methods have enabled the identification of the structure, morphology, and function of the underlying WM fibers in vivo. The purpose of this paper is to review the existing evidence about WM abnormalities in individuals at ultra-high risk of psychosis (UHR) with the use of diffusion tensor imaging (DTI) available from the National Center for Biotechnology Information PubMed (Medline) and Health Source: Nursing/Academic Edition databases. Of 358 relevant articles identified, 25 papers published in the years 2008–2020 were ultimately included in the review. Most of them supported the presence of subtle aberrations in WM in UHR individuals, especially in the superior longitudinal fasciculus (SLF), the inferior longitudinal fasciculus (ILF), and the inferior fronto-occipital fasciculus (IFOF). These alterations may therefore be considered a promising neurobiological marker for the risk of psychosis. However, due to methodological discrepancies and the relative scarcity of evidence, further investigation is called for, especially into connectome analysis in UHR patients. Full article
(This article belongs to the Special Issue Hot Topics in Schizophrenia Research - Part I)
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17 pages, 2282 KiB  
Review
A Meta-Analysis of the Influence of Antipsychotics on Cytokines Levels in First Episode Psychosis
by Piotr Marcinowicz, Magdalena Więdłocha, Natalia Zborowska, Weronika Dębowska, Piotr Podwalski, Błażej Misiak, Ernest Tyburski and Agata Szulc
J. Clin. Med. 2021, 10(11), 2488; https://0-doi-org.brum.beds.ac.uk/10.3390/jcm10112488 - 04 Jun 2021
Cited by 36 | Viewed by 2471
Abstract
Background: Cytokines have a major impact on the neurotransmitter networks that are involved in schizophrenia pathophysiology. First Episode Psychosis (FEP) patients exhibit abnormalities in cytokines levels prior to the start of treatment. Previous studies showed that antipsychotic treatment modulates cytokines levels. The aim [...] Read more.
Background: Cytokines have a major impact on the neurotransmitter networks that are involved in schizophrenia pathophysiology. First Episode Psychosis (FEP) patients exhibit abnormalities in cytokines levels prior to the start of treatment. Previous studies showed that antipsychotic treatment modulates cytokines levels. The aim of this meta-analysis is to further investigate this relationship. Methods: Several online databases were searched. For meta-analysis of selected studies, we analysed variables containing the number of cases, mean and standard deviation of IL-1β, IL-2, IL-4, IL-6, IL-10, IL-17, TNF-α, IFN-γ levels before, and after, antipsychotic treatment. Results: 12 studies were included in the meta-analysis. Our main results demonstrate that, in FEP patients, antipsychotic treatment is related to decreased concentrations of pro-inflammatory IL-1β, IL-6, IFN-γ, TNF-α and anti-inflammatory IL-4, IL-10 cytokines. On the other hand, levels of pro-inflammatory IL-2 and IL-17 remain unaffected. Conclusions: When compared with other meta-analyses of studies involving FEP individuals, results we obtained are consistent regarding decrease in IL-1β, IL-6. Comparing outcomes of our study with meta-analyses of schizophrenic subjects, in general, our results are consistent in IL-1β, IL-6, TNF-α, IFN-γ, IL-2. Our meta-analysis is the only one which indicates a decrease in anti-inflammatory IL-10 in FEP patients after antipsychotic treatment. Full article
(This article belongs to the Special Issue Hot Topics in Schizophrenia Research - Part I)
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23 pages, 762 KiB  
Review
The G Protein-Coupled Glutamate Receptors as Novel Molecular Targets in Schizophrenia Treatment—A Narrative Review
by Waldemar Kryszkowski and Tomasz Boczek
J. Clin. Med. 2021, 10(7), 1475; https://0-doi-org.brum.beds.ac.uk/10.3390/jcm10071475 - 02 Apr 2021
Cited by 3 | Viewed by 3350
Abstract
Schizophrenia is a severe neuropsychiatric disease with an unknown etiology. The research into the neurobiology of this disease led to several models aimed at explaining the link between perturbations in brain function and the manifestation of psychotic symptoms. The glutamatergic hypothesis postulates that [...] Read more.
Schizophrenia is a severe neuropsychiatric disease with an unknown etiology. The research into the neurobiology of this disease led to several models aimed at explaining the link between perturbations in brain function and the manifestation of psychotic symptoms. The glutamatergic hypothesis postulates that disrupted glutamate neurotransmission may mediate cognitive and psychosocial impairments by affecting the connections between the cortex and the thalamus. In this regard, the greatest attention has been given to ionotropic NMDA receptor hypofunction. However, converging data indicates metabotropic glutamate receptors as crucial for cognitive and psychomotor function. The distribution of these receptors in the brain regions related to schizophrenia and their regulatory role in glutamate release make them promising molecular targets for novel antipsychotics. This article reviews the progress in the research on the role of metabotropic glutamate receptors in schizophrenia etiopathology. Full article
(This article belongs to the Special Issue Hot Topics in Schizophrenia Research - Part I)
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10 pages, 287 KiB  
Review
Efficacy of Cannabidiol for Δ-9-Tetrahydrocannabinol-Induced Psychotic Symptoms, Schizophrenia, and Cannabis Use Disorders: A Narrative Review
by Francesco Bartoli, Ilaria Riboldi, Bianca Bachi, Angela Calabrese, Federico Moretti, Cristina Crocamo and Giuseppe Carrà
J. Clin. Med. 2021, 10(6), 1303; https://0-doi-org.brum.beds.ac.uk/10.3390/jcm10061303 - 22 Mar 2021
Cited by 9 | Viewed by 3530
Abstract
Although cannabis’ major psychoactive component, Δ-9-tetrahydrocannabinol (THC), has been linked to both earlier onset and poorer outcomes of psychotic disorders, Cannabidiol (CBD) seems to have different pharmacological mechanisms and potential therapeutic properties. However, no clinical study has investigated CBD for the treatment of [...] Read more.
Although cannabis’ major psychoactive component, Δ-9-tetrahydrocannabinol (THC), has been linked to both earlier onset and poorer outcomes of psychotic disorders, Cannabidiol (CBD) seems to have different pharmacological mechanisms and potential therapeutic properties. However, no clinical study has investigated CBD for the treatment of co-occurring psychotic and cannabis use disorders so far, even though its utility seems grounded in a plausible biological basis. The aim of this work is thus to provide an overview of available clinical studies evaluating the efficacy of CBD for psychotic symptoms induced by THC, schizophrenia, and cannabis use disorders. After searching for relevant studies in PubMed, Cochrane Library, and ClinicalTrials.gov, we included 10 clinical studies. Available evidence suggests that CBD may attenuate both psychotic-like symptoms induced by THC in healthy volunteers and positive symptoms in individuals with schizophrenia. In addition, preliminary data on the efficacy of CBD for cannabis use disorders show mixed findings. Evidence from ongoing clinical studies will provide insight into the possible role of CBD for treating psychotic and cannabis use disorders. Full article
(This article belongs to the Special Issue Hot Topics in Schizophrenia Research - Part I)
14 pages, 3967 KiB  
Review
Meta-Analysis on the Effect of Contingency Management for Patients with Both Psychotic Disorders and Substance Use Disorders
by Marianne Destoop, Lise Docx, Manuel Morrens and Geert Dom
J. Clin. Med. 2021, 10(4), 616; https://0-doi-org.brum.beds.ac.uk/10.3390/jcm10040616 - 06 Feb 2021
Cited by 8 | Viewed by 2786
Abstract
Background: Substance use disorders (SUD) are highly prevalent among psychotic patients and are associated with poorer clinical and functional outcomes. Effective interventions for this clinical population are scarce and challenging. Contingency management (CM) is one of the most evidence-based treatments for SUD’s, however, [...] Read more.
Background: Substance use disorders (SUD) are highly prevalent among psychotic patients and are associated with poorer clinical and functional outcomes. Effective interventions for this clinical population are scarce and challenging. Contingency management (CM) is one of the most evidence-based treatments for SUD’s, however, a meta-analysis of the effect of CM in patients with a dual diagnosis of psychotic disorder and SUD has not been performed. Methods: We searched PubMed and PsycINFO databases up to December 2020. Results: Five controlled trials involving 892 patients were included. CM is effective on abstinence rates, measured by the number of self-reported days of using after intervention (95% CI −0.98 to −0.06) and by the number of negative breath or urine samples after intervention (OR 2.13; 95% CI 0.97 to 4.69) and follow-up (OR 1.47; 95% CI 1.04 to 2.08). Conclusions: Our meta-analysis shows a potential effect of CM on abstinence for patients with SUD and (severe) psychotic disorders, although the number of studies is limited. Additional longitudinal studies are needed to confirm the sustained effectivity of CM and give support for a larger clinical implementation of CM within services targeting these vulnerable co-morbid patients. Full article
(This article belongs to the Special Issue Hot Topics in Schizophrenia Research - Part I)
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