Accelerated aging in bipolar disorder: A comprehensive review of molecular findings and their clinical implications

Oxidatively-induced DNA base damage and base excision repair abnormalities in siblings of individuals with bipolar disorder DNA damage and repair in bipolar disorder

Previous evidence suggests elevated levels of oxidatively-induced DNA damage, particularly 8-hydroxy-2'-deoxyguanosine (8-OH-dG), and abnormalities in the repair of 8-OH-dG by the base excision repair (BER) in bipolar disorder (BD). However, the genetic disposition of these abnormalities remains unknown. In this study, we aimed to investigate the levels of oxidatively-induced DNA damage and BER mechanisms in individuals with BD and their siblings, as compared to healthy controls (HCs). 46 individuals with BD, 41 siblings of individuals with BD, and 51 HCs were included in the study. Liquid chromatography-tandem mass spectrometry was employed to evaluate the levels of 8-OH-dG in urine, which were then normalized based on urine creatinine levels. The real-time-polymerase chain reaction was used to measure the expression levels of 8-oxoguanine DNA glycosylase 1 (OGG1), apurinic/apyrimidinic endonuclease 1 (APE1), poly ADP-ribose polymerase 1 (PARP1), and DNA polymerase beta (POLβ). The levels of 8-OH-dG were found to be elevated in both individuals with BD and their siblings when compared to the HCs. The OGG1 and APE1 expressions were downregulated, while POLβ expressions were upregulated in both the patient and sibling groups compared to the HCs. Age, smoking status, and the number of depressive episodes had an impact on APE1 expression levels in the patient group while body mass index, smoking status, and past psychiatric history had an impact on 8-OH-dG levels in siblings. Both individuals with BD and unaffected siblings presented similar abnormalities regarding oxidatively-induced DNA damage and BER, suggesting a link between abnormalities in DNA damage/BER mechanisms and familial susceptibility to BD. Our findings suggest that targeting the oxidatively-induced DNA damage and BER pathway could offer promising therapeutic strategies for reducing the risk of age-related diseases and comorbidities in individuals with a genetic predisposition to BD.

Putative Risk Biomarkers of Bipolar Disorder in At-risk Youth

Bipolar disorder is a highly heritable and functionally impairing disease. The recognition and intervention of BD especially that characterized by early onset remains challenging. Risk biomarkers for predicting BD transition among at-risk youth may improve disease prognosis. We reviewed the more recent clinical studies to find possible pre-diagnostic biomarkers in youth at familial or (and) clinical risk of BD. Here we found that putative biomarkers for predicting conversion to BD include findings from multiple sample sources based on different hypotheses. Putative risk biomarkers shown by perspective studies are higher bipolar polygenetic risk scores, epigenetic alterations, elevated immune parameters, front-limbic system deficits, and brain circuit dysfunction associated with emotion and reward processing. Future studies need to enhance machine learning integration, make clinical detection methods more objective, and improve the quality of cohort studies.

Epigenetic Aging Associations With Psychoneurological Symptoms and Social Functioning in Adults With Sickle Cell Disease

Objective: Sickle cell disease (SCD), the most common inherited blood disorder in the United States, is associated with severe psychoneurological symptoms. While epigenetic age acceleration has been linked to psychoneurological symptom burden in other diseases, this connection is unexplored in SCD. This study aimed to assess the association between epigenetic age acceleration and psychoneurological symptom burden in SCD. Methods: In this cross-sectional study, emotional impact, pain impact, sleep impact, social functioning, and cognitive function were assessed in 87 adults living with SCD. DNA methylation data were generated from blood specimens and used to calculate epigenetic age using five clocks (Horvath, Hannum, PhenoAge, GrimAge, & DunedinPACE). Associations between epigenetic age acceleration and symptoms were assessed. Results: The sample (N = 87) had a mean (SD) chronologic age was 30.6 (8.1) years. Epigenetic age acceleration was associated with several symptom outcomes. GrimAge age acceleration (β = -0.49, p = .03) and increased DunedinPACE (β = -2.23, p = .004) were associated with worse emotional impact scores. PhenoAge (β = -0.32, p = .04) and the GrimAge (β = -0.48, p = .05) age acceleration were associated with worse pain impact scores. Increased DunedinPACE (β = -2.07 p = .04) were associated with worse sleep impact scores. Increased DunedinPACE (β = -2.87, p = .005) was associated with worse social functioning scores. We did not find associations between epigenetic age acceleration and cognitive function in this sample. Conclusion: Epigenetic age acceleration was associated with worse symptom experiences, suggesting the potential for epigenetic age acceleration as a biomarker to aid in risk stratification or targets for intervention to mitigate symptom burden in SCD.

Decreased telomere length in a subgroup of young individuals with bipolar disorders: replication in the FACE-BD cohort and association with the shelterin component POT1

Bipolar disorder (BD) has been associated with premature cellular aging with shortened telomere length (TL) as compared to the general population. We recently identified a subgroup of young individuals with prematurely shortened TL. The aims of the present study were to replicate this observation in a larger sample and analyze the expression levels of genes associated with age or TL in a subsample of these individuals. TL was measured on peripheral blood DNA using quantitative polymerase chain reaction in a sample of 542 individuals with BD and clustering analyses were performed. Gene expression level of 29 genes, associated with aging or with telomere maintenance, was analyzed in RNA samples from a subsample of 129 individuals. Clustering analyses identified a group of young individuals (mean age 29.64 years), with shorter TL. None of the tested clinical variables were significantly associated with this subgroup. Gene expression level analyses showed significant downregulation of MYC, POT1, and CD27 in the prematurely aged young individuals compared to the young individuals with longer TL. After adjustment only POT1 remained significantly differentially expressed between the two groups of young individuals. This study confirms the existence of a subgroup of young individuals with BD with shortened TL. The observed decrease of POT1 expression level suggests a newly described cellular mechanism in individuals with BD, that may contribute to telomere shortening.

Cellular reprogramming as a tool to model human aging in a dish

The design of human model systems is highly relevant to unveil the underlying mechanisms of aging and to provide insights on potential interventions to extend human health and life span. In this perspective, we explore the potential of 2D or 3D culture models comprising human induced pluripotent stem cells and transdifferentiated cells obtained from aged or age-related disorder-affected donors to enhance our understanding of human aging and to catalyze the discovery of anti-aging interventions.

Sociodemographic and clinical characteristics of people with oldest older age bipolar disorder in a global sample: Results from the global aging and geriatric experiments in bipolar disorder project

OBJECTS

Studies of older age bipolar disorder (OABD) have mostly focused on "younger old" individuals. Little is known about the oldest OABD (OOABD) individuals aged ≥70 years old. The Global Aging and Geriatric Experiments in Bipolar Disorder (GAGE-BD) project provides an opportunity to evaluate the OOABD group to understand their characteristics compared to younger groups.

METHODS

We conducted cross-sectional analyses of the GAGE-BD database, an integrated, harmonized dataset from 19 international studies. We compared the sociodemographic and clinical characteristics of those aged <50 (YABD, n = 184), 50-69 (OABD, n = 881), and ≥70 (OOABD, n = 304). To standardize the comparisons between age categories and all characteristics, we used multinomial logistic regression models with age category as the dependent variable, with each characteristic as the independent variable, and clustering of standard errors to account for the correlation between observations from each of the studies.

RESULTS

OOABD and OABD had lower severity of manic symptoms (Mean YMRS = 3.3, 3.8 respectively) than YABD (YMRS = 7.6), and lower depressive symptoms (% of absent = 65.4%, and 59.5% respectively) than YABD (18.3%). OOABD and OABD had higher physical burden than YABD, especially in the cardiovascular domain (prevalence = 65% in OOABD, 41% in OABD and 17% in YABD); OOABD had the highest prevalence (56%) in the musculoskeletal domain (significantly differed from 39% in OABD and 31% in YABD which didn't differ from each other). Overall, OOABD had significant cumulative physical burden in numbers of domains (mean = 4) compared to both OABD (mean = 2) and YABD (mean = 1). OOABD had the lowest rates of suicidal thoughts (10%), which significantly differed from YABD (26%) though didn't differ from OABD (21%). Functional status was higher in both OOABD (GAF = 63) and OABD (GAF = 64), though only OABD had significantly higher function than YABD (GAF = 59).

CONCLUSIONS

OOABD have unique features, suggesting that (1) OOABD individuals may be easier to manage psychiatrically, but require more attention to comorbid physical conditions; (2) OOABD is a survivor cohort associated with resilience despite high medical burden, warranting both qualitative and quantitative methods to better understand how to advance clinical care and ways to age successfully with BD.

A preliminary composite of blood-based biomarkers to distinguish major depressive disorder and bipolar disorder in adolescents and adults

BACKGROUND

Since diagnosis of mood disorder heavily depends on signs and symptoms, emerging researches have been studying biomarkers with the attempt to improve diagnostic accuracy, but none of the findings have been broadly accepted. The purpose of the present study was to construct a preliminary diagnostic model to distinguish major depressive disorder (MDD) and bipolar disorder (BD) using potential commonly tested blood biomarkers.

METHODS

Information of 721 inpatients with an ICD-10 diagnosis of MDD or BD were collected from the electronic medical record system. Variables in the nomogram were selected by best subset selection method after a prior univariable screening, and then constructed using logistic regression with inclusion of the psychotropic medication use. The discrimination, calibration and internal validation of the nomogram were evaluated by the receiver operating characteristic curve (ROC), the calibration curve, cross validation and subset validation method.

RESULTS

The nomogram consisted of five variables, including age, eosinophil count, plasma concentrations of prolactin, total cholesterol, and low-density lipoprotein cholesterol. The model could discriminate between MDD and BD with an area under the ROC curve (AUC) of 0.858, with a sensitivity of 0.716 and a specificity of 0.890.

CONCLUSION

The comprehensive nomogram constructed by the present study can be convenient to distinguish MDD and BD since the incorporating variables were common indicators in clinical practice. It could help avoid misdiagnoses and improve prognosis of the patients.

Telomere length and verbal learning in bipolar disorders

INTRODUCTION

Recent studies indicate accelerated ageing processes, shorter telomere length and poorer cognitive functioning in patients with bipolar disorder. The neurobiology underlying cognitive function in bipolar disorder is yet to be established. We anticipated that accelerated ageing as indicated by shortened telomere length, would be associated with reduced cognitive performance in bipolar disorder, particularly for ageing sensitive functions such as memory and learning.

METHODS

The study consisted of 647 participants (bipolar disorder [n = 246] and healthy controls [n = 401]). All participants underwent a standardized neuropsychological test battery, including working memory, executive functioning, processing speed, verbal learning, and verbal memory. Leucocyte telomere length was measured via blood and determined by quantitative real-time Polymerase Chain Reaction (qPCR) providing a telomere to single copy ratio (T/S ratio). The T/S ratio was used as an estimate of the mean telomere length of each participant. All analyses were adjusted for medication, Daily Defined Dose (DDD), chronological age, sex, and ethnicity.

RESULTS

Patients had shorter telomere lengths than healthy controls (Cohen's d = 0.11, p = 0.01). Within patients', a positive association was observed for verbal learning and telomere length (β = 0.14, p = 0.025), along with a trend for verbal memory and telomere length (β = 0.11, p = 0.07). No other associations were observed for telomere length and cognitive functioning in the patient or the control group (p > 0.1).

CONCLUSION

Our study may suggest poorer brain health in bipolar disorder as indexed by shorter telomere length and reduced learning correlates. However, the role of telomere length on cognitive functioning in bipolar disorder seems limited.

Telomere Length Associations With Clinical Diagnosis, Age, and Polygenic Risk Scores for Anxiety Disorder, Depression, and Bipolar Disorder

Background

Accelerated biological aging might contribute to the lower life expectancy of individuals with mental disorders. The aim of this study was to characterize telomere length, a biological hallmark of aging, in individuals with mental disorders.

Methods

The UK Biobank is a multicenter community-based observational study that recruited >500,000 middle-aged and older adults. Average leukocyte telomere length (telomere repeat copy number/single-copy gene ratio) was measured using quantitative polymerase chain reaction. Polygenic risk scores (PRSs) were calculated for individuals of European ancestry. We estimated differences in telomere length between individuals with anxiety disorder, depression, or bipolar disorder and people without mental disorders and examined associations with psychotropic medication use, age, and PRSs for these 3 disorders.

Results

The analyses included up to 308,725 participants. Individuals with depression had shorter telomeres than people without mental disorders (β = -0.011, 95% CI, -0.019 to -0.004, Bonferroni-corrected p = .027). Associations between bipolar disorder and telomere length differed by lithium use. There was limited evidence that individuals with an anxiety disorder had shorter telomeres. There was no evidence that associations between age and telomere length differed between individuals with and without these disorders. PRSs for depression, but not anxiety disorder or bipolar disorder, were associated with shorter telomeres (β = -0.006, 95% CI, -0.010 to -0.003, Bonferroni-corrected p = .001).

Conclusions

Differences in telomere length were observed primarily for individuals with depression or bipolar disorder and in individuals with a higher PRS for depression. There was no evidence that the association between age and telomere length differed between individuals with and without an anxiety disorder, depression, or bipolar disorder.

A Randomized Clinical Trial to Assess the Effect of Medication Therapy Plus tDCS on Problem-solving and Emotion Regulation of Patients with Bipolar Disorder Type I

Objective

This study aims to evaluate the effectiveness of medication therapy combined with transcranial Direct Current Stimulation (tDCS) in improving problem-solving and emotion regulation abilities of patients with bipolar disorder (BD) type I.

Methods

This is a randomized clinical trial conducted on 30 patients with BD I, randomly assigned into two groups of Medication (n = 15, receiving mood stabilizers including 2-5 tablets of lithium 300 mg, sodium valproate 200 mg, and carbamazepine 200 mg) and Medication + tDCS (n = 15, receiving mood stabilizers plus tDCS with 2 mA intensity over the right dorsolateral prefrontal cortex for 10 days, two sessions per day each for 20 minutes). The Tower of London (TOL) test and Emotion Regulation Questionnaire (ERQ) were used for assessments before, immediately, and 3 months after interventions.

Results

There was a significant difference between groups in total ERQ (p = 0.001) and its cognitive reappraisal domain (p = 0.000) which were increased, but the difference was not significant in its expressive suppression domain (p > 0.05). After 3 months, their level decreased. In examining problem-solving variable, the combined therapy could significantly reduce only the total number of errors under TOL test (p = 0.00), but it remained unchanged after 3 months.

Conclusion

Medication therapy plus tDCS is effective in improving problem-solving and emotional regulation (cognitive reappraisal) skills of patients with BD I.

Immune cell subsets in patients with bipolar disorder or schizophrenia with history of childhood maltreatment

A history of Childhood Maltreatment (CM) has been repeatedly associated with an increased risk of developing bipolar disorders (BD) or schizophrenia (SZ). The impact of severe stress induced by CM has been proposed to be mediated by elevated inflammation reflected by dysregulated inflammatory processes. Little is known about the potential impact of CM on lymphocyte subpopulations or the role of pre-existing infections on CM physiological consequences. This study therefore explored the role of CM and past infection exposure impact on lymphocyte subpopulations to give an indication of their relevance as stressors in the pathoetiology of major mood and psychotic disorders. 118 adult patients with SZ, and 152 with BD were included in the analysis. CM history was assessed by the Childhood Trauma Questionnaire (CTQ), with current and past psychiatric symptomatology also evaluated. Circulating immune cell subsets were analyzed using flow cytometry-based analysis. Past exposure to common infectious stigma including toxoplasma, cytomegalovirus (CMV) and Epstein-Barr virus (EBV) were measured by solid phase-enzyme microplate and ELISA immunoassays. The relationship between CM, biological phenotypes (including immune cell subsets distribution and past infectious status) and clinical phenotypes were analyzed using univariate and multivariate analyses. BD patients with, versus without, CM had higher levels of CD3+CD8+ cytotoxic T cells and CMV antibodies along with decreased levels of CD45RA+CCR7+CD8+ naïve CD8+ T cells, and a more severe clinical profile. CMV antibody levels were inversely associated with the CD3 + CD8 + lymphocyte subset level. SZ patients with, versus without, CM, showed lower levels of CD14 + monocytes and no specific clinical characteristics. The accumulation of different types of maltreatment associated with increased body mass index and CMV autoantibodies as well as decreased levels of CD14 + monocytes. In both BD and SZ, further analysis according to the type and the number of CM subtypes showed association with specific changes in lymphocyte cell subsets, clinical profile, and infectious stigma. Adults with BD or SZ exposed to CM exhibit specific immune cell subset profiles, clinical features, and stigma of past infections. In BD, our data indicate an interplay between CM and CMV infections, which may possibly contribute to premature aging and cellular senescence, both of which have previously been shown to associate with mood disorders. Longitudinal studies of CM-exposed patients are required to clarify the interactions of CM and viral infections, including as to the pathophysiological processes driving patient symptomatology.

Microbiota-gut-brain axis mechanisms in the complex network of bipolar disorders: potential clinical implications and translational opportunities

Bipolar disorders (BD) represent a severe leading disabling mental condition worldwide characterized by episodic and often progressive mood fluctuations with manic and depressive stages. The biological mechanisms underlying the pathophysiology of BD remain incompletely understood, but it seems that there is a complex picture of genetic and environmental factors implicated. Nowadays, gut microbiota is in the spotlight of new research related to this kind of psychiatric disorder, as it can be consistently related to several pathophysiological events observed in BD. In the context of the so-called microbiota-gut-brain (MGB) axis, it is shown to have a strong influence on host neuromodulation and endocrine functions (i.e., controlling the synthesis of neurotransmitters like serotonin or mediating the activation of the hypothalamic-pituitary-adrenal axis), as well as in modulation of host immune responses, critically regulating intestinal, systemic and brain inflammation (neuroinflammation). The present review aims to elucidate pathophysiological mechanisms derived from the MGB axis disruption and possible therapeutic approaches mainly focusing on gut microbiota in the complex network of BD. Understanding the mechanisms of gut microbiota and its bidirectional communication with the immune and other systems can shed light on the discovery of new therapies for improving the clinical management of these patients. Besides, the effect of psychiatric drugs on gut microbiota currently used in BD patients, together with new therapeutical approaches targeting this ecosystem (dietary patterns, probiotics, prebiotics, and other novelties) will also be contemplated.

The Italian Framework of Bipolar Disorders in the Elderly: Old and Current Issues and New Suggestions for the Geriatric Psycho-Oncology Research

BACKGROUND

Older adults with mood disorders constitute a heterogeneous group in a complex spectrum interlinked with physical comorbidities. Worldwide, Bipolar disorders in older people (OABD) remain underestimated and underdiagnosed. OABD is challenging in the clinical setting and is associated with adverse outcomes (increased risk of anti-social behaviour triggered by inappropriate drugs and increased incidence of health deficits, including cancer). This article aims to describe the state of the art of OABD in the Italian framework and provide a new field of research.

METHODS

We performed an overview of the literature, selecting our target population (over 65 years) and synthesising the main challenging issues. By exploiting the Italian database from the Minister of Health in 2021, we analysed epidemiological data in the age range 65-74 years and 75-84 years old.

RESULTS

Females showed the highest prevalence and incidence in both groups, with a regional difference across the country but more evident in the Autonomous Provinces of Bolzano and Trento for the 65-74 years range. Several projects recently focused on this topic, and the urgency to define better the epidemiological framework is mandatory.

CONCLUSIONS

This study represented the first attempt to report the comprehensive Italian framework on OABD aimed at fostering research activities and knowledge.

Epigenetic clock analysis reveals increased plasma cystatin C levels based on DNA methylation in major depressive disorder

Major depressive disorder (MDD) is a common mental illness and a major public health concern worldwide. Depression is associated with epigenetic changes that regulate gene expression, and analyzing these changes may help elucidate the pathophysiology of MDD. Genome-wide DNA methylation (DNAm) profiles can function as 'epigenetic clocks' that can help estimate biological aging. Here, we assessed biological aging in patients with MDD using various DNAm-based indicators of epigenetic aging. We used a publicly available dataset containing data obtained from the whole blood samples of MDD patients (n = 489) and controls (n = 210). We analyzed five epigenetic clocks (HorvathAge, HannumAge, SkinBloodAge, PhenoAge, and GrimAge) and DNAm-based telomere length (DNAmTL). We also investigated seven DNAm-based age-predictive plasma proteins (including cystatin C) and smoking status, which are components of GrimAge. Following adjustment for confounding factors such as age and sex, patients with MDD showed no significant difference in epigenetic clocks and DNAmTL. However, DNAm-based plasma cystatin C levels were significantly higher in patients with MDD than controls. Our findings revealed specific DNAm changes predicting plasma cystatin C levels in MDD. These findings may help elucidate the pathophysiology of MDD, leading to the development of new biomarkers and medications.

Leukocyte telomere length and bipolar disorder risk: evidence from Mendelian randomization analysis

Objective

We aim to test whether leukocyte telomere length (LTL) is causally associated with the risk of bipolar disorder (BD) using the Mendelian randomization (MR) method.

Methods

Results of a genome-wide association study (GWAS) conducted with 472,174 individuals of European descent were used to screen for single-nucleotide polymorphisms (SNPs) related with LTL traits. Summary-level data for BD (7,647 cases and 27,303 controls) were obtained from UK Biobank. An inverse-variance-weighted (IVW) method was employed as the primary MR analysis. Sensitivity analyses were conducted via MR-Egger, maximum likelihood, MR-pleiotropy residual sum outlier (MR-PRESSO), and MR-robust adjusted profile score (MR-RAPS) methods. Finally, the MR Steiger test was utilized to validate the hypothesized relationship between exposure and outcome.

Results

Two-sample MR analysis revealed inverse relationships between genetically predicted LTL and BD risk (IVW OR [odds ratio] = 0.800, 95% CI [0.647–0.989] P = 0.039). Genetically predicted LTL exhibits a consistent connection with BD across five MR methods. Sensitivity analyses showed that the genetically determined effect of LTL on BD was stable and reliable. Furthermore, the MR Steiger test demonstrated that LTL was causal for BD rather than the opposite (P < 0.001).

Conclusion

Our findings show that genetically determined LTL reduces the risk of BD. More research is required to clarify the mechanisms underlying this apparent causal connection. In addition, these findings may be useful for developing strategies for the prevention and treatment of BD.

A comparative meta-analysis of peripheral 8-hydroxy-2'-deoxyguanosine (8-OHdG) or 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) levels across mood episodes in bipolar disorder

OBJECTIVE

Oxidative DNA damage has been associated with the pathophysiology of bipolar disorder (BD) as one of the common pathways between increased medical comorbidity and premature aging in BD. Previous evidence shows increased levels of oxidatively induced DNA damage markers, 8-hydroxy-2'-deoxyguanosine (8-OHdG) or its tautomer 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG), in patients with BD in comparison to healthy individuals. With the current research, we aim to analyze data on peripheral (blood or urine) 8-OHdG/8-oxo-dG levels across mood states of BD using a meta-analytical approach.

METHOD

A literature search was conducted using the databases PubMed, Scopus, and Web of Science to identify eligible studies (January 1989 to July 2022). Relevant studies were systematically reviewed; a random-effects meta-analysis and a meta-regression analysis were conducted.

RESULTS

The current meta-analysis included 12 studies consisting of 808 BD patients (390 in euthymia, 156 in mania, 137 in depression, 16 in mixed episode, 109 not specified) and 563 healthy controls. BD patients that were currently depressed had significantly higher levels of 8-OHdG/8-oxo-dG than healthy controls, while euthymic or manic patients did not differ from healthy controls. A meta-regression analysis showed sex distribution (being female) and older age to be significantly related to increased 8-OHdG/8-oxo-dG levels.

CONCLUSION

Our findings suggest that 8-OHdG/8-oxo-dG may be a state-related marker of depression in BD and may be affected by older age and female gender.

Biomarkers of neuroprogression and late staging in bipolar disorder: A systematic review

BACKGROUND

Bipolar disorder may undertake a progressive course in a subset of patients, and research efforts have been made to understand the biological basis underlying this process. This systematic review examined the literature available on biological markers associated with illness progression in bipolar disorder.

METHODS

Peer-reviewed articles were assessed using Embase, PsycINFO and PubMed, as well as from external sources. After initial screening, a total of 871 citations from databases and other sources were identified. Participants with a diagnosis of bipolar disorder were included in our systematic review; however, studies with participants younger than 15 or older than 65 were excluded. All studies were assessed using the Newcastle-Ottawa Scale assessment tool, and data pertaining to the results were extracted into tabular form using Google Sheets and Google Documents. The systematic review was registered on PROSPERO international prospective register of systematic reviews (ID Number: CRD42020154305).

RESULTS

A total of 35 studies were included in the systematic review. Increased ventricular size and reduction of grey matter volume were the most common brain changes associated with illness progression in bipolar disorder. Among the several biomarkers evaluated in this systematic review, findings also indicate a role of peripheral inflammatory markers in this process.

DISCUSSION

The studies evaluating the biological basis of the illness progression in bipolar disorder are still scarce and heterogeneous. However, current evidence supports the notion of neuroprogression, the pathophysiological process related to progressive brain changes associated with clinical progression in patients with bipolar disorder. The increase in peripheral inflammatory biomarkers and the neuroanatomical changes in bipolar disorder suggest progressive systemic and structural brain alterations, respectively.

A five-year follow-up of the verbal memory performance of individuals with bipolar disorder and schizophrenia: evidence of unchanging deficits under treatment

OBJECTIVE

Bipolar disorder (BD) and schizophrenia (SZ) are chronic and heterogeneous mental disorders that present cognitive and functional impairments. Verbal memory is considered an important predictor of functioning and a domain vulnerable to the aging process. However, only few studies investigate the progression of memory longitudinally in BD and SZ, especially in lower- and middle-income countries. Therefore, we aim to evaluate the course of verbal memory in individuals with BD and SZ.

METHODS

We assessed 31 individuals with BD and 27 individuals with SZ under treatment at outpatient clinics at baseline and after five years. They were assessed through a sociodemographic questionnaire, memory and estimated IQ (eIQ) instruments, and clinical scales.

RESULTS

Individuals with SZ showed worse verbal memory performance in comparison to BD, however, we did not observe changes over time within patient groups. Individuals with BD with higher eIQ showed a better verbal memory performance, while no effect of eIQ was found for subjects with SZ.

CONCLUSION

Patients with SZ and BD showed different levels of verbal memory impairment, although they had similar unchanging trajectories after 5 years under psychiatric treatment. This finding indicates a relative stable cognitive course for both disorders.

Depression, aging, and immunity: implications for COVID-19 vaccine immunogenicity

The aging process can have detrimental effects on the immune system rendering the elderly more susceptible to infectious disease and less responsive to vaccination. Major depressive disorder (MDD) has been hypothesized to show characteristics of accelerated biological aging. This raises the possibility that depressed individuals will show some overlap with elderly populations with respect to their immune response to infection and vaccination. Here we provide an umbrella review of this literature in the context of the SARS CoV-2 pandemic. On balance, the available data do indeed suggest that depression is a risk factor for both adverse outcomes following COVID-19 infection and for reduced COVID-19 vaccine immunogenicity. We conclude that MDD (and other major psychiatric disorders) should be recognized as vulnerable populations that receive priority for vaccination along with other at-risk groups.

Telomere length and mitochondrial DNA copy number in bipolar disorder: A sibling study

OBJECTIVES

An accelerated cellular ageing has been observed in bipolar disorder (BD) using biomarkers such as telomere length (TL) and mitochondrial DNA copy number (mtDNAcn). Several risk factors might drive premature ageing in individuals with BD, including a familial predisposition. This study compared TL and mtDNAcn between individuals with BD and their (un)-affected siblings, and explored factors that may explain proband-sibling differences.

METHODS

Sixty individuals with BD and seventy-four siblings (34 affected with BD or mood disorders and 40 unaffected) were included. Quantitative polymerase chain reaction (qPCR) was used to measure TL and mtDNAcn from peripheral blood genomic DNA.

RESULTS

TL and mtDNAcn did not significantly differ between probands and their siblings, whatever these latter were affected or not with mood disorders. However, the correlation plots of TL or mtDNAcn in proband-sibling pairs suggested that some pairs were discordant. The within proband-sibling pairs differences for TL and mtDNAcn were not explained by differences in all tested factors.

CONCLUSIONS

This study shows that probands with BD and their siblings are concordant for TL and mtDNAcn suggesting that they may share some environmental or genetic determinants of these two biomarkers of cellular ageing.

Analysis on in vitro effect of lithium on telomere length in lymphoblastoid cell lines from bipolar disorder patients with different clinical response to long-term lithium treatment

Background

It has been suggested that bipolar disorder (BD) is associated with clinical and biological features of accelerated aging. In our previous studies, we showed that long-term lithium treatment was correlated with longer leukocyte telomere length (LTL) in BD patients. A recent study explored the role of TL in BD using patients-derived lymphoblastoid cell lines (LCLs), showing that baseline TL was shorter in BD compared to controls and that lithium in vitro increased TL but only in BD. Here, we used the same cell system (LCLs) to explore if a 7-day treatment protocol with lithium chloride (LiCl) 1 mM was able to highlight differences in TL between BD patients clinically responders (Li-R; n = 15) or non-responders (Li-NR; n = 15) to lithium, and if BD differed from non-psychiatric controls (HC; n = 15).

Results

There was no difference in TL between BD patients and HC. Moreover, LiCl did not influence TL in the overall sample, and there was no difference between diagnostic or clinical response groups. Likewise, LiCl did not affect TL in neural precursor cells from healthy donors.

Conclusions

Our findings suggest that a 7-day lithium treatment protocol and the use of LCLs might not represent a suitable approach to deepen our understanding on the role of altered telomere dynamics in BD as previously suggested by studies in vivo.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40246-022-00418-8.

Severe psychiatric disorders and general medical comorbidities: inflammation-related mechanisms and therapeutic opportunities

Individuals with severe psychiatric disorders, such as mood disorders and schizophrenia, are at increased risk of developing other medical conditions, especially cardiovascular and metabolic diseases. These medical conditions are underdiagnosed and undertreated in these patients contributing to their increased morbidity and mortality. The basis for this increased comorbidity is not well understood, possibly reflecting shared risks factors (e.g. lifestyle risk factors), shared biological mechanisms and/or reciprocal interactions. Among overlapping pathophysiological mechanisms, inflammation and related factors, such as dysbiosis and insulin resistance, stand out. Besides underlying the association between psychiatric disorders and cardiometabolic diseases, these mechanisms provide several potential therapeutic targets.

Association of Oxidative Stress-Induced Nucleic Acid Damage With Psychiatric Disorders in Adults: A Systematic Review and Meta-analysis

IMPORTANCE

Nucleic acid damage from oxidative stress (NA-OXS) may be a molecular mechanism driving the severely increased morbidity and mortality from somatic causes in adults with psychiatric disorders.

OBJECTIVE

To systematically retrieve and analyze data on NA-OXS across the psychiatric disorder diagnostic spectrum.

DATA SOURCES

The PubMed, Embase, and PsycINFO databases were searched from inception to November 16, 2021. A hand search of reference lists of relevant articles was also performed.

STUDY SELECTION

Key study inclusion criteria in this meta-analysis were as follows: adult human study population, measurement of any marker of DNA or RNA damage from oxidative stress, and either a (1) cross-sectional design comparing patients with psychiatric disorders (any diagnosis) with a control group or (2) prospective intervention. Two authors screened the studies, and 2 senior authors read the relevant articles in full and assessed them for eligibility.

DATA EXTRACTION AND SYNTHESIS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed. Two authors performed data extraction independently, and a senior coauthor was consulted in cases of disagreement. Data were synthesized with random-effects and multilevel meta-analyses.

MAIN OUTCOMES AND MEASURES

The predefined hypothesis was that individuals with psychiatric disorders have increased NA-OXS levels. The main outcome was the standardized mean differences (SMDs) among patients and controls in nucleic acid oxidation markers compared across diagnostic groups. Analyses were divided into combinations of biological matrices and nucleic acids.

RESULTS

Eighty-two studies fulfilled the inclusion criteria, comprising 205 patient vs control group comparisons and a total of 10 151 patient and 10 532 control observations. Overall, the data showed that patients with psychiatric disorders had higher NA-OXS levels vs controls across matrices and molecules. Pooled effect sizes ranged from moderate for urinary DNA markers (SMD = 0.44 [95% CI, 0.20-0.68]; P < .001) to very large for blood cell DNA markers (SMD = 1.12 [95% CI, 0.69-1.55; P < .001). Higher NA-OXS levels were observed among patients with dementias followed by psychotic and bipolar disorders. Sensitivity analyses excluding low-quality studies did not materially alter the results. Intervention studies were few and too heterogenous for meaningful meta-analysis.

CONCLUSIONS AND RELEVANCE

The results of this meta-analysis suggest that there is an association with increased NA-OXS levels in individuals across the psychiatric disorder diagnostic spectrum. NA-OXS may play a role in the somatic morbidity and mortality observed among individuals with psychiatric disorders.

Epigenetic GrimAge acceleration and cognitive impairment in bipolar disorder

Bipolar disorder (BD) has been previously associated with clinical signs of premature aging, including accelerated epigenetic aging in blood and brain, and a steeper age-related decline in cognitive function. However, the clinical drivers and cognitive correlates of epigenetic aging in BD are still unknown. We aimed to investigate the relationship between multiple measures of epigenetic aging acceleration with clinical, functioning, and cognitive outcomes in patients with BD and controls. Blood genome-wide DNA methylation levels were measured in BD patients (n = 153) and matched healthy controls (n = 50) with the Infinium MethylationEPIC BeadChip (Illumina). Epigenetic age estimates were calculated using an online tool, including the recently developed lifespan predictor GrimAge, and analyzed with generalized linear models controlling for demographic variables and blood cell proportions. BD was significantly associated with greater GrimAge acceleration (AgeAccelGrim, β=0.197, p = 0.009), and significant group-dependent interactions were found between AgeAccelGrim and blood cell proportions (CD4+ T-lymphocytes, monocytes, granulocytes, and B-cells). Within patients, higher AgeAccelGrim was associated with worse cognitive function in multiple domains (short-term affective memory (β=-0.078, p = 0.030), short-term non-affective memory (β=-0.088, p = 0.018), inhibition (β=0.064, p = 0.046), and problem solving (β=-0.067, p = 0.034)), age of first diagnosis with any mood disorder (β=-0.076, p = 0.039) or BD (β=-0.102, p = 0.016), as well as with current non-smoking status (β=-0.392, p < 0.001). Overall, our findings support the contribution of epigenetic factors to the aging-related cognitive decline and premature mortality reported in BD patients, with an important driving effect of smoking in this population.

Epigenetic age dysregulation in individuals with bipolar disorder and schizophrenia

Bipolar disorder (BD) and schizophrenia (SCZ) are debilitating disorders that are associated with significant burden and reduced quality of life. In this study, we leveraged microarray data derived from both the Illumina HumanMethylation450 platform to investigate the epigenetic age of individuals with SCZ (n = 40), BD (n = 40), and healthy controls (n = 38), across five epigenetic clocks. Various statistical metrics were used to identify discrepancies between epigenetic and chronological age across the three groups. We observed a significant increase in epigenetic age compared to chronological age in the BD group. Mean epigenetic age acceleration was also higher in individuals with bipolar disorder compared to healthy controls across four different epigenetic clocks (p<0.05). Despite the study's relatively small sample size, these findings suggest that both individuals with bipolar disorder and schizophrenia may have epigenetic markers associated with a premature aging phenotype, which could be suggestive of negative outcomes associated with the disease. In our future studies, we hope to elucidate this finding further by elucidating the precise link between epigenetic age, symptomatology and disease progression.

Neuroimaging Studies of Brain Structure in Older Adults with Bipolar Disorder: A Review

Bipolar disorder (BD) is a common mood disorder that can have severe consequences during later life, including suffering and impairment due to mood and cognitive symptoms, elevated risk for dementia and an especially high risk for suicide. Greater understanding of the brain circuitry differences involved in older adults with BD (OABD) in later life and their relationship to aging processes is required to improve outcomes of OABD. The current literature on gray and white matter findings, from high resolution structural and diffusion-weighted magnetic resonance imaging (MRI) studies, has shown that BD in younger age groups is associated with gray matter reductions within cortical and subcortical brain regions that subserve emotion processing and regulation, as well as reduced structural integrity of white matter tracts connecting these brain regions. While fewer neuroimaging studies have focused on OABD, it does appear that many of the structural brain differences found in younger samples are present in OABD. There is also initial suggestion that there are additional brain differences, for at least a subset of OABD, that may result from more pronounced gray and white matter declines with age that may contribute to adverse outcomes. Preclinical and clinical data supporting neuro-plastic and -protective effects of mood-stabilizing medications, suggest that treatments may reverse and/or prevent the progression of brain changes thereby reducing symptoms. Future neuroimaging research implementing longitudinal designs, and large-scale, multi-site initiatives with detailed clinical and treatment data, holds promise for reducing suffering, cognitive dysfunction and suicide in OABD.

Dynamic and Static Cognitive Deficits in Schizophrenia and Bipolar Disorder After the First Episode

Few studies have comprehensively examined the profile of cognitive functioning in first episode psychosis patients throughout the lifespan, and from first episode to chronic stage. We assessed functioning in general and specific cognitive functions, comparing both schizophrenia (N = 64) and bipolar I (N = 19) patients to controls (N = 103). Participants were from a population-based, case-control study of first episode psychosis patients, who were followed prospectively up to 10 years post first admission. A cognitive battery was administered at baseline and follow-up. By combining longitudinal and cross-sectional data, we were able to examine the cognitive profile of patients and controls throughout the entire age range of our sample (16-65). Schizophrenia patients exhibited widespread declines in IQ, executive function, visual memory, language ability, and verbal knowledge. However, the ages at which these declines occurred differed between functions. Deficits in verbal memory, working memory, processing speed, and visuospatial ability, on the other hand, were present at the first episode, and remained relatively static thereafter. Bipolar I patients also showed declines in IQ, verbal knowledge, and language ability, albeit at different ages to schizophrenia patients and only in verbal functions. Deficits on measures of verbal memory, processing speed, and executive function remained relatively static. Thus, both schizophrenia and bipolar I patients experienced cognitive decline in general and specific functions after the first episode, but the age at which these declines occurred differed between disorder and function. Cognitive remediation efforts may be most fruitful when targeting individual functions during specific time periods throughout adulthood.

A Possible Antidepressive Effect of Dietary Interventions: Emergent Findings and Research Challenges

Purpose

Despite recent advancements in the treatment of depression, the prevalence of affected individuals continues to grow. The development of new strategies has been required and emerging evidence has linked a possible antidepressant effect with dietary interventions. In this review, we discuss recent findings about the possible antidepressant effect of dietary interventions with an emphasis on the results of randomized controlled trials.

Recent findings

A high consumption of refined sugars and saturated fat and a low dietary content of fruits and vegetables has been associated with the development of depression. There is evidence supporting a small to moderate beneficial effect of a Mediterranean-type diet in depression. In addition, new dietary protocols are being studied for their use as possible interventions, such as the ketogenic diet, Nordic diet, and plant-based diet.

Summary

Lifestyle interventions surrounding diet and nutrition are a relatively affordable way to enhance response to treatment and to be employed as an adjunct in mental health care. Most studies, however, are limited by the difficulty in controlling for the placebo effect. Mediterranean-style diets seem to be the most promising as an adjunctive treatment for mood disorders. Larger randomized controlled trials that could assess predictors of response to dietary interventions are needed to establish a clear positive effect of diet and guide clinical care and nutritional recommendations concerning mental health care.

Telomere length and mitochondrial DNA copy number in bipolar disorder: identification of a subgroup of young individuals with accelerated cellular aging

The 10-15-years decrease in life expectancy observed in individuals with bipolar disorder (BD) has been linked to the concept of accelerated cellular aging. Telomere length (TL) and mitochondrial DNA copy number (mtDNAcn) have been proposed as markers of cellular aging and comparisons between individuals with BD and healthy controls (HC) sometimes led to conflicting results. Previous studies had moderate sample sizes and studies combining these two markers into a single analysis are scarce. Using quantitative polymerase chain reaction, we measured both TL and mtDNAcn in DNA (peripheral blood) in a sample of 130 individuals with BD and 78 HC. Regression analyses, receiver operating characteristic (ROC), and clustering analyses were performed. We observed significantly lower TL and mtDNAcn in individuals with BD as compared to HC (respective decrease of 26.5 and 35.8%). ROC analyses showed that TL and mtDNAcn highly discriminated groups (AUC = 0.904 for TL and AUC = 0.931 for mtDNAcn). In the whole population, clustering analyses identified a group of young individuals (age around 36 years), with accelerated cellular aging (both shorter TL and lower mtDNAcn), which consisted mostly of individuals with BD (85.5%). The subgroup of patients with young age but accelerated aging was not characterized by specific clinical variables related to the course of BD or childhood maltreatment. However, patients in this subgroup were more frequently treated with anticonvulsants. Further characterization of this subgroup is required to better understand the molecular mechanisms and the risk factors of accelerated cellular aging in BD.

Blue Light Blocking Treatment for the Treatment of Bipolar Disorder: Directions for Research and Practice

Recent results from a small number of clinical studies have resulted in the suggestion that the process of blocking the transmission of shorter-wavelength light (‘blue light’ with a wave length of 450 nm to 470 nm) may have a beneficial role in the treatment of bipolar disorder. This critical review will appraise the quality of evidence so far as to these claims, assess the neurobiology that could be implicated in the underlying processes while introducing a common set of research criteria for the field.

Neurofilaments light: Possible biomarker of brain modifications in bipolar disorder

INTRODUCTION

Brain white matter (WM) abnormalities are biomarkers that seem to be involved in bipolar disorder (BD) aetiology and maintenance. Evidences suggest a possible association between neurodegeneration, neuroaxonal alterations and BD. A biomarker that is recently drawing attention is neurofilaments light (NfL) chain, a cytoskeletal intermediate filament protein expressed in neurons. To investigate neuroimaging alterations associated with BD, we studied the association between NfL levels and WM microstructure.

METHODS

NfL plasma quantification was performed in a sample of 45 depressed BD patients compared with 29 healthy controls (HC) using Quanterix SIMOA assay. Statistical analysis were conducted to evaluate NfL levels differences between BD patients and controls. Analyses of the diffusion data were performed using Tract Based Spatial Statistics (TBSS) on Diffusion Tensor images acquired using a 3.0 Tesla MR scanner.

RESULTS

Patients had higher NfL levels than HC (9.13 ± 4.78 vs 4.28 ± 2.39 pg/ml; p < 0.001). The separate-slopes analysis of variance showed a significant interaction of age with diagnosis (Likelihood-ratio test: χ2 = 27.52, p < 0.0001) with significant effects only in the BD sample (p = 0.023). The TBSS analysis, performed within the BD sample, showed a significant positive correlation between NfL levels and axial diffusivity (AD) in a wide single cluster encompassing several tracts.

DISCUSSION

Our results suggest that the physiological age-dependent increment of NfL level is augmented in BD, possibly because of increased remodelling and plasticity processes related to an accelerated ageing condition. The positive association between NfL levels and AD, may reflect a condition of remyelination and axonal regeneration.

Therapeutic Interventions to Mitigate Mitochondrial Dysfunction and Oxidative Stress–Induced Damage in Patients with Bipolar Disorder

Bipolar disorder (BD) is characterized by mood changes, including recurrent manic, hypomanic, and depressive episodes, which may involve mixed symptoms. Despite the progress in neurobiological research, the pathophysiology of BD has not been extensively described to date. Progress in the understanding of the neurobiology driving BD could help facilitate the discovery of therapeutic targets and biomarkers for its early detection. Oxidative stress (OS), which damages biomolecules and causes mitochondrial and dopamine system dysfunctions, is a persistent finding in patients with BD. Inflammation and immune dysfunction might also play a role in BD pathophysiology. Specific nutrient supplements (nutraceuticals) may target neurobiological pathways suggested to be perturbed in BD, such as inflammation, mitochondrial dysfunction, and OS. Consequently, nutraceuticals may be used in the adjunctive treatment of BD. This paper summarizes the possible roles of OS, mitochondrial dysfunction, and immune system dysregulation in the onset of BD. It then discusses OS-mitigating strategies that may serve as therapeutic interventions for BD. It also analyzes the relationship between diet and BD as well as the use of nutritional interventions in the treatment of BD. In addition, it addresses the use of lithium therapy; novel antipsychotic agents, including clozapine, olanzapine, risperidone, cariprazine, and quetiapine; and anti-inflammatory agents to treat BD. Furthermore, it reviews the efficacy of the most used therapies for BD, such as cognitive–behavioral therapy, bright light therapy, imagery-focused cognitive therapy, and electroconvulsive therapy. A better understanding of the roles of OS, mitochondrial dysfunction, and inflammation in the pathogenesis of bipolar disorder, along with a stronger elucidation of the therapeutic functions of antioxidants, antipsychotics, anti-inflammatory agents, lithium therapy, and light therapies, may lead to improved strategies for the treatment and prevention of bipolar disorder.

Accelerated epigenetic age and shortened telomere length based on DNA methylation in Nicolaides-Baraitser syndrome

BACKGROUND

Nicolaides-Baraitser syndrome (NCBRS) is a rare disorder characterized by neurodevelopmental delays, seizures, and diverse physical characteristics. The DNA methylation (DNAm) profile in NCBRS is significantly different. DNAm is linked to the biological aging of cells and the health risks associated with biological aging. In this study, we examined changes in biological ages in NCBRS to provide insights into the prognosis and health risks of NCBRS.

METHODS

We used a publicly available dataset to examine biological aging in NCBRS using DNAm-based epigenetic ages, such as PhenoAge and GrimAge, as well as DNAm-based estimator of telomere length (DNAmTL). We investigated 12 cases, clinically diagnosed as NCBRS, and 27 controls.

RESULTS

Compared to controls, NCBRS cases exhibited significantly accelerated PhenoAge and GrimAge as well as significantly shortened DNAmTL.

CONCLUSION

These results suggest an acceleration of biological aging in NCBRS and provide insights into the prognosis and health risks of NCBRS.

Brain age in mood and psychotic disorders: a systematic review and meta-analysis

OBJECTIVE

To evaluate whether accelerated brain aging occurs in individuals with mood or psychotic disorders.

METHODS

A systematic review following PRISMA guidelines was conducted. A meta-analysis was then performed to assess neuroimaging-derived brain age gap in three independent groups: (1) schizophrenia and first-episode psychosis, (2) major depressive disorder, and (3) bipolar disorder.

RESULTS

A total of 18 papers were included. The random-effects model meta-analysis showed a significantly increased neuroimaging-derived brain age gap relative to age-matched controls for the three major psychiatric disorders, with schizophrenia (3.08; 95%CI [2.32; 3.85]; p < 0.01) presenting the largest effect, followed by bipolar disorder (1.93; [0.53; 3.34]; p < 0.01) and major depressive disorder (1.12; [0.41; 1.83]; p < 0.01). The brain age gap was larger in older compared to younger individuals.

CONCLUSION

Individuals with mood and psychotic disorders may undergo a process of accelerated brain aging reflected in patterns captured by neuroimaging data. The brain age gap tends to be more pronounced in older individuals, indicating a possible cumulative biological effect of illness burden.

Unlocking the Complexity of Mitochondrial DNA: A Key to Understanding Neurodegenerative Disease Caused by Injury

Neurodegenerative disorders that are triggered by injury typically have variable and unpredictable outcomes due to the complex and multifactorial cascade of events following the injury and during recovery. Hence, several factors beyond the initial injury likely contribute to the disease progression and pathology, and among these are genetic factors. Genetics is a recognized factor in determining the outcome of common neurodegenerative diseases. The role of mitochondrial genetics and function in traditional neurodegenerative diseases, such as Alzheimer’s and Parkinson’s diseases, is well-established. Much less is known about mitochondrial genetics, however, regarding neurodegenerative diseases that result from injuries such as traumatic brain injury and ischaemic stroke. We discuss the potential role of mitochondrial DNA genetics in the progression and outcome of injury-related neurodegenerative diseases. We present a guide for understanding mitochondrial genetic variation, along with the nuances of quantifying mitochondrial DNA variation. Evidence supporting a role for mitochondrial DNA as a risk factor for neurodegenerative disease is also reviewed and examined. Further research into the impact of mitochondrial DNA on neurodegenerative disease resulting from injury will likely offer key insights into the genetic factors that determine the outcome of these diseases together with potential targets for treatment.

Plasma fatty acid-binding protein 7 concentration correlates with depression/anxiety, cognition, and positive symptom in patients with schizophrenia

Because of the involvement of the brain in the pathophysiology of psychiatric disorders, obtaining information on the biochemical features that directly contribute to symptoms is challenging. The present study aimed to assess fatty acid-binding protein 7 (FABP7) expressed specifically in the brain and detectable in the peripheral blood and to investigate the correlation between blood FABP7 concentration and symptoms. We recruited 30, 29, and 35 patients with schizophrenia, bipolar disorder, and depression and evaluated using the Positive and Negative Syndrome Scale (PANSS), Young Mania Rating Scale (YMRS), and Hamilton Depression Rating Scale (HAMD-21), respectively. Plasma FABP7 concentrations correlated with PANSS scores (R² = 0.3305, p < 0.001) but not with other scales. In the analysis of the relationship between five dimensions of schizophrenia symptoms derived from the PANSS 5-factor model and measured plasma FABP7 concentrations, severities of depression/anxiety, cognition, and positive symptom were significantly correlated with plasma FABP7 concentrations. Further molecular investigation of the functional and kinetic analyses of FABP7 is necessary to understand the relationship of this protein with schizophrenia pathology. Nevertheless, the present study suggests that FABP7 can be a biological indicator reflecting the pathogenesis of schizophrenia and has potential applications as a biomarker for diagnosis and symptom assessment.

Decreased leucocyte telomere length in male patients with chronic bipolar disorder: lack of effect of long-term lithium treatment

OBJECTIVES

Bipolar disorder (BD) may be connected with accelerated aging, the marker of this can be shorter telomere length (TL). Some data suggest that lithium may exert a protective effect against telomere shortening. The study aimed to compare the TL between patients with BD and control subjects. The effect of long-term lithium treatment was also assessed.

METHODS

The study group comprised 41 patients with BD, including 29 patients treated longitudinally with lithium (mean 16.5 years) and 20 healthy people. TL was assessed by the quantitative polymerase chain reaction (qPCR).

RESULTS

In the control group, the TL was significantly longer in males than in females. Male bipolar patients had significantly shorter TL compared with the control male group. In bipolar patients, there was no correlation between TL and duration of treatment. The TL was negatively correlated with age in male bipolar patients.

CONCLUSIONS

The study did not confirm the lithium effect on TL in bipolar patients. TL showed gender differences, being shorter in BD males, compared to control males, and longer in healthy males, compared to control females.

Low peripheral mitochondrial DNA copy number during manic episodes of bipolar disorders is associated with disease severity and inflammation

Mitochondria (Mt) are intra-cellular components essential for cellular energy processes whose dysfunction may induce premature cellular senescence and/or inflammation, both observed in bipolar disorders (BD). We investigated mitochondrial DNA copy number (mtDNAcn) levels in patients with BD being in manic, depressive or euthymic phase and in healthy controls (HC) both characterized for the levels of blood-based inflammatory markers and stigma of pathogens. 312 patients with BD were compared to 180 HC. mtDNAcn were measured using a digital droplet PCR. Serum levels of 14 inflammatory molecules and 3 anti-infectious IgG stigma were respectively evaluated by electro-chemiluminescence, ELISA and dedicated immunoassays. The statistical analyses were performed using Spearman's correlation, Wilcoxon signed-rank and Kruskal-Wallis rank sum tests. P-values were adjusted for multiple testing with Benjamini-Hochberg method. We found low levels of mtDNAcn in BD patients as compared to HC (P = 0.008) especially during manic episodes (P = 0.0002). We also observed that low levels of mtDNAcn are negatively correlated with mood and psychotic scales (PANSS, YMRS and CGI) (adjusted P (Adj P) = 0.02, 0.003 and 0.05 respectively) and positively with the GAF severity scale (Adj P = 0.002). They were also correlated with high levels of both intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 (Adj P = 0.003 and 0.001) along with a trend toward increased IL-2, IL-10 and B2M circulating levels (Adj P = 0.05). Here, we report correlations between marker of mitochondria functioning and both clinical scales and inflammatory markers in BD patients experiencing manic episodes. If replicated, these finding might allow to predict transition between disease phases and to design accurate therapeutic options.

Emerging methods for and novel insights gained by absolute quantification of mitochondrial DNA copy number and its clinical applications

The past thirty years have seen a surge in interest in pathophysiological roles of mitochondria, and the accurate quantification of mitochondrial DNA copy number (mCN) in cells and tissue samples is a fundamental aspect of assessing changes in mitochondrial health and biogenesis. Quantification of mCN between studies is surprisingly variable due to a combination of physiological variability and diverse protocols being used to measure this endpoint. The advent of novel methods to quantify nucleic acids like digital polymerase chain reaction (dPCR) and high throughput sequencing offer the ability to measure absolute values of mCN. We conducted an in-depth survey of articles published between 1969 -- 2020 to create an overview of mCN values, to assess consensus values of tissue-specific mCN, and to evaluate consistency between methods of assessing mCN. We identify best practices for methods used to assess mCN, and we address the impact of using specific loci on the mitochondrial genome to determine mCN. Current data suggest that clinical measurement of mCN can provide diagnostic and prognostic value in a range of diseases and health conditions, with emphasis on cancer and cardiovascular disease, and the advent of means to measure absolute mCN should improve future clinical applications of mCN measurements.

Accelerated aging signatures in subjects with schizophrenia and their unaffected siblings

Schizophrenia (SZ) is a chronic debilitating disease. Subjects with SZ have significant shorter life expectancy. Growing evidence suggests that a process of pathological accelerated aging occurs in SZ, leading to early development of severe clinical diseases and worse morbimortality. Furthermore, unaffected relatives can share certain endophenotypes with subjects with SZ. We aim to characterize accelerated aging as a possible endophenotype of schizophrenia by using a machine learning (ML) model of peripheral biomarkers to accurately differentiate subjects with SZ (n = 35), their unaffected siblings (SB, n = 36) and healthy controls (HC, n = 47). We used a random forest algorithm that included biomarkers related to aging: eotaxins CCL-11 and CCL-24; the oxidative stress markers thiobarbituric acid-reactive substances (TBARS), protein carbonyl content (PCC), glutathione peroxidase (GPx); and telomere length (TL). The ML algorithm of biomarkers was able to distinguish individuals with SZ from HC with prediction accuracy of 79.7%, SZ from SB with 62.5% accuracy and SB from HC with 75.5% accuracy. These results support the hypothesis that a pathological accelerated aging might occur in SZ, and this pathological aging could be an endophenotype of the disease, once this profile was also observed in SB, suggesting that SB might suffer from an accelerated aging in some level.

Mini-review: The anti-aging effects of lithium in bipolar disorder

The medical use of lithium has grown since its initial introduction in the 1800s as a treatment for gout. Today, the divalent cation remains as the pharmacological gold standard in treatment of bipolar disorder (BD) with strong mood stabilizing effects. Lithium has demonstrated efficacy in the treatment of acute affective episodes, in the reduction of affective episode recurrence, and in significantly decreasing the risk of suicide in patients. BD has been consistently associated with clinical signs of accelerated aging, including increased rates of age-related diseases such as cardiovascular diseases, malignancies, and diabetes mellitus. This clinical scenario parallels accelerated aging mechanisms observed on a molecular basis, with studies reporting shortened telomeres, increased oxidative stress, and accelerated epigenetic aging in patients with BD compared to controls. Lithium has proved useful as a potential agent in slowing down this accelerated aging process in BD, potentially reversing effects induced by the disorder. This mini-review summarizes findings of anti-aging mechanisms associated with lithium use and provides a discussion of the clinical implications and perspectives of this evolving field. Despite many promising results, more studies are warranted in order to elucidate the exact mechanism by which lithium may act as an anti-aging agent and the extent to which these mechanisms are relevant to its mood stabilizing properties in BD.

Chrysin's Impact on Oxidative and Inflammation Damages in the Liver of Aged Male Rats

AIM

The purpose of this research was to investigate the effect of chrysin on one of the natural antioxidants on aging progression in an animal model.

BACKGROUND

Oxidative stress and inflammation increase in hepatic tissue during aging, leading to liver dysfunction.

OBJECTIVE

The current research was conducted to show the effect of chrysin on the activities of antioxidant enzyme (catalase, glutathione peroxidase, and superoxide dismutase), serum nitric oxide (NO), and lipid peroxidation as well as inflammatory cytokines (TNF-α, IL-6, and IL-1β) of aging rats.

METHODS

Male Wistar rats of different ages, 2, 10, and 20 months, were randomly divided into six groups as follows (n=8, per each group): young control rats (C2), young CH-treated rats (CH2), middle- aged control rats (C10), middle-aged CH-treated group (CH10), aged control group (C20), and aged CH-treated group (CH20). Chrysin (20 mg/kg) was administered intraperitoneally once a day for 30 days.

RESULT

Present findings indicated that chrysin treatment ameliorated the increased liver levels of lipid peroxidation, TNF-α, and IL-1β as well as serum levels of NO.

CONCLUSION

The findings suggest that chrysin could be effective against the progression of ageinduced damage by modulation of oxidant-antioxidant system and inflammatory response.

Risk of cancer in bipolar disorder and the potential role of lithium: International collaborative systematic review and meta-analyses

We examined bipolar disorder (BD) as a risk factor for developing cancer and the role of lithium on cancer incidence. We conducted two systematic review and meta-analyses of population-based studies providing data on these associations. We screened articles indexed in MEDLINE, Scopus, Embase, and PsycINFO up to August 2020. The first random-effects meta-analysis, based on 4,910,661 individuals from nine studies estimated an increased risk of cancer of any kind [RR = 1.24 (1.05-1.46); p < 0.01], especially breast cancer [RR = 1.33 (1.15-1.55); p < 0.01] in BD. The second random-effects meta-analysis, based on 2,606,187 individuals from five studies did not show increased risk of cancer in people with BD using lithium, and even suggested a small protective effect both in overall [RR = 0.94 (0.72-1.22); p = 0.66] and urinary cancer [RR = 0.93 (0.75-1.14); p = 0.48] although these findings did not reach statistical significance. The current evidence highlights that cancer risk is increased in individuals with BD, particularly breast cancer in women. Lithium may have a potential protective effect on cancer, including urinary cancer. The role of lithium as a mainstay of treatment for BD is reinforced by this study.

Cellular Senescence Affects Cardiac Regeneration and Repair in Ischemic Heart Disease

Ischemic heart disease (IHD) is defined as a syndrome of ischemic cardiomyopathy. Myogenesis and angiogenesis in the ischemic myocardium are important for cardiomyocyte (CM) survival, improving cardiac function and decreasing the progression of heart failure after IHD. Cellular senescence is a state of permanent irreversible cell cycle arrest caused by stress that results in a decline in cellular functions, such as proliferation, migration, homing, and differentiation. In addition, senescent cells produce the senescence-associated secretory phenotype (SASP), which affects the tissue microenvironment and surrounding cells by secreting proinflammatory cytokines, chemokines, growth factors, and extracellular matrix degradation proteins. The accumulation of cardiovascular-related senescent cells, including vascular endothelial cells (VECs), vascular smooth muscle cells (VSMCs), CMs and progenitor cells, is an important risk factor of cardiovascular diseases, such as vascular aging, atherosclerotic plaque formation, myocardial infarction (MI) and ventricular remodeling. This review summarizes the processes of angiogenesis, myogenesis and cellular senescence after IHD. In addition, this review focuses on the relationship between cellular senescence and cardiovascular disease and the mechanism of cellular senescence. Finally, we discuss a potential therapeutic strategy for MI targeting senescent cells.

Mitochondrial dysfunction as a critical event in the pathophysiology of bipolar disorder

The understanding of the pathophysiology of bipolar disorder (BD) remains modest, despite recent advances in neurobiological research. The mitochondrial dysfunction hypothesis of bipolar disorder has been corroborated by several studies involving postmortem brain analysis, neuroimaging, and specific biomarkers in both rodent models and humans. Evidence suggests that BD might be related to abnormal mitochondrial morphology and dynamics, neuroimmune dysfunction, and atypical mitochondrial metabolism and oxidative stress pathways. Mitochondrial dysfunction in mood disorders is also associated with abnormal Ca2+ levels, glutamate excitotoxicity, an imbalance between pro- and antiapoptotic proteins towards apoptosis, abnormal gene expression of electron transport chain complexes, and decreased ATP synthesis. This paper aims to review and discuss the implications of mitochondrial dysfunction in BD etiology and to explore mitochondria as a potential target for novel therapeutic agents.

Bipolar disorder: An evolutionary psychoneuroimmunological approach

Bipolar disorder is a mental health disorder characterized by extreme shifts in mood, high suicide rate, sleep problems, and dysfunction of psychological traits like self-esteem (feeling inferior when depressed and superior when manic). Bipolar disorder is rare among populations that have not adopted contemporary Western lifestyles, which supports the hypothesis that bipolar disorder results from a mismatch between Homo sapiens's evolutionary and current environments. Recent studies have connected bipolar disorder with low-grade inflammation, the malfunctioning of the internal clock, and the resulting sleep disturbances. Stress is often a triggering factor for mania and sleep problems, but stress also causes low-grade inflammation. Since inflammation desynchronizes the internal clock, chronic stress and inflammation are the primary biological mechanisms behind bipolar disorder. Chronic stress and inflammation are driven by contemporary Western lifestyles, including stressful social environments, unhealthy dietary patterns, limited physical activity, and obesity. The treatment of bipolar disorder should focus on reducing stress, stress sensitivity, and inflammation by lifestyle changes rather than just temporarily alleviating symptoms with psychopharmacological interventions.

The Role of Mitochondria in Mood Disorders: From Physiology to Pathophysiology and to Treatment

Mitochondria are cellular organelles involved in several biological processes, especially in energy production. Several studies have found a relationship between mitochondrial dysfunction and mood disorders, such as major depressive disorder and bipolar disorder. Impairments in energy production are found in these disorders together with higher levels of oxidative stress. Recently, many agents capable of enhancing antioxidant defenses or mitochondrial functioning have been studied for the treatment of mood disorders as adjuvant therapy to current pharmacological treatments. A better knowledge of mitochondrial physiology and pathophysiology might allow the identification of new therapeutic targets and the development and study of novel effective therapies to treat these specific mitochondrial impairments. This could be especially beneficial for treatment-resistant patients. In this article, we provide a focused narrative review of the currently available evidence supporting the involvement of mitochondrial dysfunction in mood disorders, the effects of current therapies on mitochondrial functions, and novel targeted therapies acting on mitochondrial pathways that might be useful for the treatment of mood disorders.

The Discovery of Clinically Applicable Biomarkers for Bipolar Disorder: A Review of Candidate and Proteomic Approaches

Bipolar disorder (BD) is a severe psychiatric condition which affects innumerable people across the globe. The etiopathogenesis of BD is multi-faceted with genetic, environmental and psychosocial factors playing a role. Hitherto, the diagnosis and management of BD are purely on empirical grounds as we lack confirmed biomarkers for this condition. In this regard, hypothesis-driven investigations have been unable to identify clinically applicable biomarkers, steering the field towards newer technologies. Innovative, state-of-the-art techniques like multiplex immunoassays and mass spectrometry can potentially investigate the entire proteome. By detecting up or down regulated proteins, novel biomarkers are identified and new postulates about the etiopathogenesis of BD are specified. Hence, biological pathways are uncovered which are involved in the initiation and advancement of the disease and new therapeutic targets are identified. In this manuscript, the extant literature is thoroughly reviewed and the latest findings on candidate BD biomarkers are provided, followed by an overview of the proteomic approaches. It was found that due to the heterogeneous nature of BD no single biomarker is feasible, instead a panel of tests is more likely to be useful. With the application of latest technologies, it is expected that validated biomarkers will be discovered which will be useful as diagnostic tools and help in the delivery of individually tailored therapies to the patients.