Therapeutic Mechanisms of Lithium in Bipolar Disorder: Recent Advances and Current Understanding

Biodegradable Zn-Li-Sr alloy implants with antioxidant properties for improved bone osseointegration under diabetic conditions

The repair of bone defects under diabetes mellitus remains challenging due to the hyperglycaemic environment that tends to initiate oxidative stress, leading to poor bone healing. Therefore, the biodegradable, antioxidant and pro-osseointegration properties of bone implants are essential for the healing of diabetic bone defects. Addressing this issue requires bone implants with specialized properties, including biodegradability, antioxidant activity, and the ability to enhance pro-osseointegration. Herein, we developed a novel degradable Zn-Li-Sr ternary alloy aimed at alleviating oxidative stress and promoting the regeneration of diabetic bone defects. Results have shown that the coupling of Zn, Li and Sr not only resists oxidative damage, but also promotes the proliferation and differentiation of osteoblasts. The Zn-Li-Sr alloy implants have been shown to possess multifunctional properties, such as promoting osteogenesis and exhibiting antioxidant activity in vitro, while also facilitating bone ingrowth and osseointegration in vivo. Beyond biological advantages, the alloying of Li and Sr endowed the Zn alloy with significantly improved tensile strength for mechanical support with up to 6 times the UTS and 8 times the YS of pure Zn, and a uniform degradation mode to prevent localized rupture. Overall, Zn-Li-Sr alloy implants demonstrate promising applications for bone regeneration under diabetic conditions, their multifunctional properties not only address the physiological challenges posed by diabetes but also provide robust mechanical support and controlled degradation. This study provides valuable insights into the design and potential clinical applications of implants for bone regeneration under diabetic conditions.

Underlying biological mechanisms of emotion dysregulation in bipolar disorder

Difficulties with emotion regulation (ER) are a key feature of bipolar disorder (BD) contributing to poor psychosocial and functional outcomes. Abnormalities within emotion processing and regulation thus provide key targets for treatment strategies and have implications for treatment response. Although biological mechanisms and ER are typically studied independently, emergent findings in BD research suggest that there are important ties between biological mechanisms and the disturbances in ER observed in BD. Therefore, in this narrative review, we provide an overview of the literature on biological mechanisms underlying emotional dysregulation in BD including genetic and epigenetic mechanisms, neuroimaging findings, inflammation, hypothalamic-pituitary-adrenal (HPA) axis dysfunction, neuroplasticity and brain-derived neurotrophic factor (BDNF), and circadian rhythm disturbances. Finally, we discuss the clinical relevance of the findings and provide future directions for research. The continued exploration of underlying biological mechanisms in ED in BD may not only elucidate fundamental neurobiological mechanisms but also foster advancements in current treatment strategies and the development of novel targeted treatments.

Lithium in cardiovascular health and disease: Pharmacological and clinical implications

Lithium, a cornerstone therapy for bipolar disorder (BD), produces complex and dual effects on cardiovascular health. This review synthesizes current evidence on the direct and indirect cardiovascular effects of lithium. Direct effects include dose-dependent influences on cardiac development, hypertrophy, fibrosis, mitochondrial function, and arrhythmia. While therapeutic doses may confer cardioprotective benefits by inhibiting GSK-3β, which activates the Wnt/β-catenin signaling pathway and modulates anti-inflammatory pathways, supratherapeutic levels exacerbate oxidative stress, mitochondrial dysfunction, and arrhythmogenicity. Indirectly, lithium modulates cardiovascular outcomes caused by renal dysfunction, metabolic syndrome, and neuroendocrine-immune interactions. Clinical studies suggested that there is reduced cardiovascular mortality in lithium-treated BD patients, potentially offsetting its adverse metabolic effects. However, conflicting evidence persists, particularly regarding dose specificity and long-term outcomes. Future research should focus on high-quality clinical trials to clarify the balance between therapeutic benefits and adverse effects of lithium to ensure its safe and effective use in clinical practice.

Machine learning for predicting medical outcomes associated with acute lithium poisoning

The use of machine learning algorithms and artificial intelligence in medicine has attracted significant interest due to its ability to aid in predicting medical outcomes. This study aimed to evaluate the effectiveness of the random forest algorithm in predicting medical outcomes related to acute lithium toxicity. We analyzed cases recorded in the National Poison Data System (NPDS) between January 1, 2014, and December 31, 2018. We highlighted instances of acute lithium toxicity in patients with ages ranging from 0 to 89 years. A random forest model was employed to predict serious medical outcomes, including those with a major effect, moderate effect, or death. Predictions were made using the pre-defined NPDS coding criteria. The model's predictive performance was assessed by computing accuracy, recall (sensitivity), and F1-score. Of the 11,525 reported cases of lithium poisoning documented during the study, 2,760 cases were categorized as acute lithium overdose. One hundred thirty-nine individuals experienced severe outcomes, whereas 2,621 patients endured minor outcomes. The random forest model exhibited exceptional accuracy and F1-scores, achieving values of 99%, 98%, and 98% for the training, validation, and test datasets, respectively. The model achieved an accuracy rate of 100% and a sensitivity rate of 96% for important results. In addition, it achieved a 96% accuracy rate and a sensitivity rate of 100% for minor outcomes. The SHapley Additive exPlanations (SHAP) study found factors, including drowsiness/lethargy, age, ataxia, abdominal pain, and electrolyte abnormalities, significantly influenced individual predictions. The random forest algorithm achieved a 98% accuracy rate in predicting medical outcomes for patients with acute lithium intoxication. The model demonstrated high sensitivity and precision in accurately predicting significant and minor outcomes. Further investigation is necessary to authenticate these findings.

Trace amine-associated receptors as potential targets for the treatment of anxiety and depression

In the metabolic pathways associated with major biogenic amines, such as dopamine, noradrenaline, and serotonin, there exists a group of compounds known as trace amines. These trace amines share structural similarities with the major biogenic amines. Since the discovery of trace amine-associated receptors (TAARs) that are activated by trace amines, numerous studies have suggested that these receptors, particularly the TAAR1 subfamily, play a role in modulating the stress response and are involved in stress-related psychiatric disorders, including depression, bipolar disorder, and anxiety. Research indicates that TAAR1 regulates the release of neurotransmitters like dopamine and serotonin, which may be a potential mechanism underlying the involvement of trace amines and TAAR1 in response to stress. Several selective TAAR1 agonists have been evaluated in various animal models of depression and anxiety, showing that these compounds can be effective in alleviating depressive and anxiety-like behaviors. Additionally, TAAR5 has also been found to have an effect on anxiety; it is proposed that a TAAR5 antagonist might produce anxiolytic effects. Despite our limited understanding of the underlying mechanisms through which TAARs regulates stress-related disorders, current evidence strongly suggests that TAAR ligands could represent novel pharmacotherapy for treating psychiatric disorders such as depression, bipolar disorder, and anxiety disorders like post-traumatic stress disorder (PTSD). This offers hope for more effective and safer treatment options in the field of mental health.

The Mechanisms of Lithium Action: The Old and New Findings

Despite lithium's presence in modern psychiatry for three-quarters of a century, the mechanisms of its therapeutic action have not been fully elucidated. This article presents the evolution of the views on these mechanisms, and both the old and new findings are discussed. Among the old mechanisms, lithium's effect on the purinergic system; electrolyte metabolism; membrane transport; and second messenger systems, namely, cyclic nucleotide and phosphatidylinositol (PI), glycogen synthase kinase-3beta (GSK-3β), brain-derived neurotrophic factor, and neurotransmitters, are discussed. The new data were obtained from in vitro studies, molecular biology, and genetic research. They showed the effects of lithium on the immune system, biological rhythms, telomere functions, and mitochondria. In this article, each lithium mechanism is considered in the light of its association with the pathogenesis of bipolar disorder or/and as a marker of the lithium response. Although not exhaustive, this review elucidates the multiple potential mechanisms of lithium action. It was also observed that many seemingly "old" mechanisms have experienced a resurgence in research conducted during the 21st century. Additionally, many studies converged on the previously postulated mechanisms of lithium inhibiting GSK-3β and PI.

Pathway-Specific Polygenic Scores for Lithium Response for Predicting Clinical Lithium Treatment Response in Patients with Bipolar Disorder

Background

Polygenic scores (PGSs) hold the potential to identify patients who respond favourably to specific psychiatric treatments. However, their biological interpretations remain unclear. In this study, we developed pathway-specific PGSs (PS PGS ) for lithium response and assessed their association with clinical lithium response in patients with bipolar disorder (BD).

Methods

Using sets of genes involved in pathways affected by lithium, we developed nine PS PGSs and evaluated their associations with lithium response in the International Consortium on Lithium Genetics cohort (ConLi + Gen: N = 2367), validated in the combined PsyCourse (N = 105) and BipoLife (N = 102) cohorts. Lithium responsiveness was assessed using the Retrospective Assessment of the Lithium Response Phenotype Scale (ALDA scale), for categorical outcome (good vs poor response) and continuous ALDA total score. Logistic and linear regressions, adjusting for age, sex, chip type, and the first four genetic principal components, were used to test associations, after multiple testing corrections ( p <0.05).

Results

Response to lithium was associated with PS PGS for acetylcholine, GABA, calcium channel signalling, mitochondria, circadian rhythm, and GSK pathways, R² ranging from 0.29% to 1.91%, with R² of 3.71% for the combined PS PGS. Associations for GABA PGS and CIR PGS were replicated. In decile-based stratified analysis, patients with the highest genetic loading (10 th decile) for acetylcholine pathway genetic variants were 3.03 times (95%CI: 1.95 - 4.69) more likely to have a good lithium response than the lowest decile (1 st decile).

Conclusion

PS PGSs achieved predictive performance comparable with conventional genome-wide PGSs, with more biological interpretability and using a smaller list of genetic variants, facilitating further investigation into the interaction of variants and biological pathways underlying lithium response.

From Serendipity to Precision: Integrating AI, Multi-Omics, and Human-Specific Models for Personalized Neuropsychiatric Care

Background/Objectives: The dual forces of structured inquiry and serendipitous discovery have long shaped neuropsychiatric research, with groundbreaking treatments such as lithium and ketamine resulting from unexpected discoveries. However, relying on chance is becoming increasingly insufficient to address the rising prevalence of mental health disorders like depression and schizophrenia, which necessitate precise, innovative approaches. Emerging technologies like artificial intelligence, induced pluripotent stem cells, and multi-omics have the potential to transform this field by allowing for predictive, patient-specific interventions. Despite these advancements, traditional methodologies such as animal models and single-variable analyses continue to be used, frequently failing to capture the complexities of human neuropsychiatric conditions. Summary: This review critically evaluates the transition from serendipity to precision-based methodologies in neuropsychiatric research. It focuses on key innovations such as dynamic systems modeling and network-based approaches that use genetic, molecular, and environmental data to identify new therapeutic targets. Furthermore, it emphasizes the importance of interdisciplinary collaboration and human-specific models in overcoming the limitations of traditional approaches. Conclusions: We highlight precision psychiatry's transformative potential for revolutionizing mental health care. This paradigm shift, which combines cutting-edge technologies with systematic frameworks, promises increased diagnostic accuracy, reproducibility, and efficiency, paving the way for tailored treatments and better patient outcomes in neuropsychiatric care.

MicroRNA Expression Profile Is Altered by Short-Term and Chronic Lithium Treatment in a Rat Model of Depression

Depression is a common disease that affects 3.8% of the global population. Despite various antidepressant treatments, one-third of patients do not respond to antidepressants, therefore augmentation with mood stabilizers such as lithium may be required in this group. One of the suggested pathomechanisms of depression is the dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and recent reports showed that microRNAs (miRNA) can impact its activity by epigenetic regulation. We aimed to explore the miRNA expression profile in the depression model and its changes upon short-term and chronic lithium treatment in the rat brain (pituitary, hypothalamus, and hippocampus). We used a chronic mild stress rat model of depression and short- and long-term lithium treatment. The behavior was assessed by an open-field test. The miRNA expression profile in the pituitary was estimated by sequencing and validated in the hypothalamus and hippocampus with qPCR. We found several miRNAs in the pituitary that were significantly altered between CMS-exposed and control rats as well as after short- and long-term lithium treatment. MicroRNAs chosen for validation in the hypothalamus and hippocampus (rno-miR-146a-5p, rno-miR-127-3p) showed no significant changes in expression. We performed in silico analysis and estimated potential pathways involved in lithium action for miRNAs differentially expressed in the pituitary at different time points. Specific microRNA subsets showed altered expression in the pituitary in depression model upon short- and long-term lithium treatment. We identified that biological pathways of target genes for these altered miRNAs differ, with the Foxo pathway potentially involved in disease development.

A physical perspective on lithium therapy

Lithium salts have strong medical properties in neurological disorders such as bipolar disorder and lithium-responsive headaches. They have recently gathered attention due to their potential preventive effect in viral infections. Though the therapeutic effect of lithium was documented by Cade in the late 1940s, its underlying mechanism of action is still disputed. Acute lithium exposure has an activating effect on excitable organic tissue and organisms, and is highly toxic. Lithium exposure is associated with a strong metabolic response in the organism, with large changes in phospholipid and cholesterol expression. Opposite to acute exposure, this metabolic response alleviates excessive cellular activity. The presence of lithium ions strongly affects lipid conformation and membrane phase unlike other alkali ions, with consequences for membrane permeability, buffer property and excitability. This review investigates how lithium ions affect lipid membrane composition and function, and how lithium response might in fact be the body's attempt to counteract the physical presence of lithium ions at cell level. Ideas for further research in microbiology and drug development are discussed.

Development progress of drugs for bipolar disorder: 75 Years after lithium proved effective

Bipolar disorder, a psychiatric condition identified by significant mood changes and a considerable genetic connection with schizophrenia, needs continuous and extensive management due to its common onset in adolescence and significant impact on psychosocial activities. While traditional mood stabilizers continue to be widely used, the pursuit of more effective treatments remains ongoing, with the current research targeting various stages of the disorder. This study provides a thorough examination of new pharmacological treatments for bipolar disorder, which are currently in Phase II and Phase III clinical trials up to 22 April 2024. A systematic search was conducted using the NIH National Library of Medicine, focusing on both repurposed and innovative drugs now in advanced stages of testing. The study identifies several promising therapeutic agents, including those intended for severe mood disorders with suicidal tendencies, and others aimed at treating mood-related neuroinflammation. Drugs that enhance dopamine stabilization and those that act on serotonin receptor activities were found notable. We also explored the strategic repurposing of already existing medications for broader therapeutic uses and looked into the potential of new formulations designed for the immediate management of symptoms. Our analysis highlights two main strategies for tackling bipolar disorder: finding new uses for existing drugs and developing new medications with unique actions. This approach shows continuous improvement in drug treatments, helping patients manage their condition better and addressing the complicated nature of bipolar disorder.

A review of diffusion MRI in mood disorders: mechanisms and predictors of treatment response

By measuring the molecular diffusion of water molecules in brain tissue, diffusion MRI (dMRI) provides unique insight into the microstructure and structural connections of the brain in living subjects. Since its inception, the application of dMRI in clinical research has expanded our understanding of the possible biological bases of psychiatric disorders and successful responses to different therapeutic interventions. Here, we review the past decade of diffusion imaging-based investigations with a specific focus on studies examining the mechanisms and predictors of therapeutic response in people with mood disorders. We present a brief overview of the general application of dMRI and key methodological developments in the field that afford increasingly detailed information concerning the macro- and micro-structural properties and connectivity patterns of white matter (WM) pathways and their perturbation over time in patients followed prospectively while undergoing treatment. This is followed by a more in-depth summary of particular studies using dMRI approaches to examine mechanisms and predictors of clinical outcomes in patients with unipolar or bipolar depression receiving pharmacological, neurostimulation, or behavioral treatments. Limitations associated with dMRI research in general and with treatment studies in mood disorders specifically are discussed, as are directions for future research. Despite limitations and the associated discrepancies in findings across individual studies, evolving research strongly indicates that the field is on the precipice of identifying and validating dMRI biomarkers that could lead to more successful personalized treatment approaches and could serve as targets for evaluating the neural effects of novel treatments.

An open label pilot trial of low-dose lithium for young people at ultra-high risk for psychosis

AIM

Lithium, even at low doses, appears to offer neuroprotection against a wide variety of insults. In this controlled pilot, we examined the safety (i.e., side-effect profile) of lithium in a sample of young people identified at ultra-high risk (UHR) for psychosis. The secondary aim was to explore whether lithium provided a signal of clinical efficacy in reducing transition to psychosis compared with treatment as usual (TAU).

METHODS

Young people attending the PACE clinic at Orygen, Melbourne, were prescribed a fixed dose (450 mg) of lithium (n = 25) or received TAU (n = 78). The primary outcome examined side-effects, with transition to psychosis, functioning and measures of psychopathology assessed as secondary outcomes.

RESULTS

Participants in both groups were functionally compromised (lithium group GAF = 56.6; monitoring group GAF = 56.9). Side-effect assessment indicated that lithium was well-tolerated. 64% (n = 16) of participants in the lithium group were lithium-adherent to week 12. Few cases transitioned to psychosis across the study period; lithium group 4% (n = 1); monitoring group 7.7% (n = 6). There was no difference in time to transition to psychosis between the groups. No group differences were observed in other functioning and symptom domains, although all outcomes improved over time.

CONCLUSIONS

With a side-effect profile either comparable to, or better than UHR antipsychotic trials, lithium might be explored for further research with UHR young people. A definitive larger trial is needed to determine the efficacy of lithium in this cohort.

Retrospective analysis of lithium treatment: examination of blood levels

Introduction

Lithium is a key medication for treating various neuropsychiatric disorders, with a narrow therapeutic index and significant drug interactions. Monitoring lithium blood levels is crucial. This study aims to investigate the relationship between lithium blood levels and demographic characteristics such as age and gender, as well as possible drug interactions, in patients with a history of lithium use who applied to various services and outpatient clinics.

Materials & methods

The files of 438 patients who were admitted to various services and outpatient clinics of Kırklareli Training and Research Hospital between January 1 and December 31, 2023, were retrospectively reviewed. Patients' blood lithium levels, gender, age, service/outpatient clinic they admitted to, other medications used, urea, creatinine, and eGFR values were recorded.

Results

When the demographic characteristics of 438 patients were examined, 62% were female (270), 38% were male (168), and the average age was 46.3 ± 14.8 years, showing a normal distribution. It was found that 192 patients (71 males, 121 females) had therapeutic lithium blood levels, while 244 patients (97 males, 147 females) had levels below 0.6 mmol/L. Two female patients had blood levels above the therapeutic range (1.23 and 1.43 mmol/L). Among the clinics and services, the four most frequented were the psychiatry clinic (314 patients), internal medicine clinic (36 patients), emergency service (27 patients), and medical oncology clinic (17 patients). Of the 314 patients admitted to the psychiatry clinic, 168 had therapeutic drug levels; only 7 of the 36 admitted to internal medicine had therapeutic levels; 12 of the 27 patients in the emergency service had therapeutic levels; and all 17 patients in medical oncology had levels below therapeutic limits.

Discussion

The data emphasize the importance of regular blood level monitoring to ensure lithium treatment's efficacy and patient safety. It is noteworthy that most patients in the psychiatry clinic had therapeutic drug levels, while those in other clinics had lower levels.

Conclusion

In conclusion, this study highlights the importance of regular blood level monitoring to ensure the efficacy and safety of lithium treatment.

Progress and trends of research on mineral elements for depression

Objective

To explore the research progress and trends on mineral elements and depression.

Methods

After querying the MeSH database and referring to the search rules, the search terms were selected and optimized to obtain the target literature collection. We analyzed the general characteristics of the literature, conducted network clustering and co-occurrence analysis, and carried out a narrative review of crucial literature.

Results

Bipolar disorder was a dominant topic in the retrieved literature, which saw a significant increase in 2010 and 2019-2020. Most studies focused on mineral elements, including lithium, calcium, magnesium, zinc, and copper. The majority of journals and disciplines were in the fields of psychiatry, neuropsychology, neuropharmacology, nutrition, medical informatics, chemistry, and public health. The United States had the highest proportion in terms of paper sources, most-cited articles, high-frequency citations, frontier citations, and high centrality citation. Regarding the influence of academic institutions, the top five were King's College London, the Chinese Academy of Sciences, University of Barcelona, INSERM, and Heidelberg University. Frontier keywords included bipolar disorder, drinking water, (neuro)inflammation, gut microbiota, and systematic analysis. Research on lithium response, magnesium supplementation, and treatment-resistant unipolar depression increased significantly after 2013.

Conclusion

Global adverse events may have indirectly driven the progress in related research. Although the literature from the United States represents an absolute majority, its influence on academic institutions is relatively weaker. Multiple pieces of evidence support the efficacy of lithium in treating bipolar disorder (BD). A series of key discoveries have led to a paradigm shift in research, leading to increasingly detailed studies on the role of magnesium, calcium, zinc, and copper in the treatment of depression. Most studies on mineral elements remain diverse and inconclusive. The potential toxicity and side effects of some elements warrant careful attention.

Intracellular effects of lithium in aging neurons

Lithium therapy received approval during the 1970s, and it has been used for its antidepressant, antimanic, and anti-suicidal effects for acute and long-term prophylaxis and treatment of bipolar disorder (BPD). These properties have been well established; however, the molecular and cellular mechanisms remain controversial. In the past few years, many studies demonstrated that at the cellular level, lithium acts as a regulator of neurogenesis, aging, and Ca2+ homeostasis. At the molecular level, lithium modulates aging by inhibiting glycogen synthase kinase-3β (GSK-3β), and the phosphatidylinositol (PI) cycle; latter, lithium specifically inhibits inositol production, acting as a non-competitive inhibitor of inositol monophosphatase (IMPase). Mitochondria and peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) have been related to lithium activity, and its regulation is mediated by GSK-3β degradation and inhibition. Lithium also impacts Ca2+ homeostasis in the mitochondria modulating the function of the lithium-permeable mitochondrial Na+-Ca2+exchanger (NCLX), affecting Ca2+ efflux from the mitochondrial matrix to the endoplasmic reticulum (ER). A close relationship between the protease Omi, GSK-3β, and PGC-1α has also been established. The purpose of this review is to summarize some of the intracellular mechanisms related to lithium activity and how, through them, neuronal aging could be controlled.

New Advances in the Pharmacology and Toxicology of Lithium: A Neurobiologically Oriented Overview

Over the last six decades, lithium has been considered the gold standard treatment for the long-term management of bipolar disorder due to its efficacy in preventing both manic and depressive episodes as well as suicidal behaviors. Nevertheless, despite numerous observed effects on various cellular pathways and biologic systems, the precise mechanism through which lithium stabilizes mood remains elusive. Furthermore, there is recent support for the therapeutic potential of lithium in other brain diseases. This review offers a comprehensive examination of contemporary understanding and predominant theories concerning the diverse mechanisms underlying lithium's effects. These findings are based on investigations utilizing cellular and animal models of neurodegenerative and psychiatric disorders. Recent studies have provided additional support for the significance of glycogen synthase kinase-3 (GSK3) inhibition as a crucial mechanism. Furthermore, research has shed more light on the interconnections between GSK3-mediated neuroprotective, antioxidant, and neuroplasticity processes. Moreover, recent advancements in animal and human models have provided valuable insights into how lithium-induced modifications at the homeostatic synaptic plasticity level may play a pivotal role in its clinical effectiveness. We focused on findings from translational studies suggesting that lithium may interface with microRNA expression. Finally, we are exploring the repurposing potential of lithium beyond bipolar disorder. These recent findings on the therapeutic mechanisms of lithium have provided important clues toward developing predictive models of response to lithium treatment and identifying new biologic targets. SIGNIFICANCE STATEMENT: Lithium is the drug of choice for the treatment of bipolar disorder, but its mechanism of action in stabilizing mood remains elusive. This review presents the latest evidence on lithium's various mechanisms of action. Recent evidence has strengthened glycogen synthase kinase-3 (GSK3) inhibition, changes at the level of homeostatic synaptic plasticity, and regulation of microRNA expression as key mechanisms, providing an intriguing perspective that may help bridge the mechanistic gap between molecular functions and its clinical efficacy as a mood stabilizer.

Oxytocin as neuro-hormone and neuro-regulator exert neuroprotective properties: A mechanistic graphical review

BACKGROUND

Neurodegeneration is progressive cell loss in specific neuronal populations, often resulting in clinical consequences with significant medical, societal, and economic implications. Because of its antioxidant, anti-inflammatory, and anti-apoptotic properties, oxytocin has been proposed as a potential neuroprotective and neurobehavioral therapeutic agent, including modulating mood disturbances and cognitive enchantment.

METHODS

Literature searches were conducted using the following databases Web of Science, PubMed, Elsevier Science Direct, Google Scholar, the Core Collection, and Cochrane from January 2000 to February 2023 for articles dealing with oxytocin neuroprotective properties in preventing or treating neurodegenerative disorders and diseases with a focus on oxidative stress, inflammation, and apoptosis/cell death.

RESULTS

The neuroprotective effects of oxytocin appears to be mediated by its anti-inflammatory properties, inhibition of neuro inflammation, activation of several antioxidant enzymes, inhibition of oxidative stress and free radical formation, activation of free radical scavengers, prevent of mitochondrial dysfunction, and inhibition of apoptosis.

CONCLUSION

Oxytocin acts as a neuroprotective agent by preventing neuro-apoptosis, neuro-inflammation, and neuronal oxidative stress, and by restoring mitochondrial function.

Impact of lithium on mortality among older adults with major psychiatric disorders: A 5-year prospective multicenter study

OBJECTIVE

Prior studies report conflicting results about the association between lithium use and all-cause mortality. In addition, data are scarce on this association among older adults with psychiatric disorders. In this report, we sought to examine the associations of lithium use with all-cause mortality and specific causes of death (i.e., due to cardiovascular disorder, non-cardiovascular disease, accident, or suicide) among older adults with psychiatric disorders during a 5-year follow-up period.

METHODS

In this observational epidemiological study, we used data from 561 patients belonging to a Cohort of individuals with Schizophrenia or Affective disorders aged 55-years or more (CSA). Patients taking lithium at baseline were first compared to patients not taking lithium, and then to patients taking (i) antiepileptics and (ii) atypical antipsychotics in sensitivity analyses. Analyses were adjusted for socio-demographic (e.g., age, gender), clinical characteristics (e.g., psychiatric diagnosis, cognitive functioning), and other psychotropic medications (e.g. benzodiazepines).

RESULTS

There was no significant association between lithium use and all-cause mortality [AOR=1.12; 95%CI=0.45-2.79; p=0.810] or disease-related mortality [AOR=1.37; 95%CI=0.51-3.65; p=0.530]. None of the 44 patients taking lithium died from suicide, whereas 4.0% (N=16) of patients not receiving lithium did.

CONCLUSION

These findings suggest that lithium may not be associated with all-cause or disease-related mortality and might be associated with reduced risk of suicide in this population. They argue against the underuse of lithium as compared with antiepileptics and atypical antipsychotics among older adults with mood disorders.

Non-canonical pathways in the pathophysiology and therapeutics of bipolar disorder

Bipolar disorder (BD) is characterized by extreme mood swings ranging from manic/hypomanic to depressive episodes. The severity, duration, and frequency of these episodes can vary widely between individuals, significantly impacting quality of life. Individuals with BD spend almost half their lives experiencing mood symptoms, especially depression, as well as associated clinical dimensions such as anhedonia, fatigue, suicidality, anxiety, and neurovegetative symptoms. Persistent mood symptoms have been associated with premature mortality, accelerated aging, and elevated prevalence of treatment-resistant depression. Recent efforts have expanded our understanding of the neurobiology of BD and the downstream targets that may help track clinical outcomes and drug development. However, as a polygenic disorder, the neurobiology of BD is complex and involves biological changes in several organelles and downstream targets (pre-, post-, and extra-synaptic), including mitochondrial dysfunction, oxidative stress, altered monoaminergic and glutamatergic systems, lower neurotrophic factor levels, and changes in immune-inflammatory systems. The field has thus moved toward identifying more precise neurobiological targets that, in turn, may help develop personalized approaches and more reliable biomarkers for treatment prediction. Diverse pharmacological and non-pharmacological approaches targeting neurobiological pathways other than neurotransmission have also been tested in mood disorders. This article reviews different neurobiological targets and pathophysiological findings in non-canonical pathways in BD that may offer opportunities to support drug development and identify new, clinically relevant biological mechanisms. These include: neuroinflammation; mitochondrial function; calcium channels; oxidative stress; the glycogen synthase kinase-3 (GSK3) pathway; protein kinase C (PKC); brain-derived neurotrophic factor (BDNF); histone deacetylase (HDAC); and the purinergic signaling pathway.

Role of microtubule actin crosslinking factor 1 (MACF1) in bipolar disorder pathophysiology and potential in lithium therapeutic mechanism

Bipolar affective disorder (BPAD) are life-long disorders that account for significant morbidity in afflicted patients. The etiology of BPAD is complex, combining genetic and environmental factors to increase the risk of disease. Genetic studies have pointed toward cytoskeletal dysfunction as a potential molecular mechanism through which BPAD may arise and have implicated proteins that regulate the cytoskeleton as risk factors. Microtubule actin crosslinking factor 1 (MACF1) is a giant cytoskeletal crosslinking protein that can coordinate the different aspects of the mammalian cytoskeleton with a wide variety of actions. In this review, we seek to highlight the functions of MACF1 in the nervous system and the molecular mechanisms leading to BPAD pathogenesis. We also offer a brief perspective on MACF1 and the role it may be playing in lithium's mechanism of action in treating BPAD.

Does circadian dysrhythmia drive the switch into high- or low-activation states in bipolar I disorder?

OBJECTIVES

Emerging evidence suggests a role of circadian dysrhythmia in the switch between "activation" states (i.e., objective motor activity and subjective energy) in bipolar I disorder.

METHODS

We examined the evidence with respect to four relevant questions: (1) Are natural or environmental exposures that can disrupt circadian rhythms also related to the switch into high-/low-activation states? (2) Are circadian dysrhythmias (e.g., altered rest/activity rhythms) associated with the switch into activation states in bipolar disorder? (3) Do interventions that affect the circadian system also affect activation states? (4) Are associations between circadian dysrhythmias and activation states influenced by other "third" factors?

RESULTS

Factors that naturally or experimentally alter circadian rhythms (e.g., light exposure) have been shown to relate to activation states; however future studies need to measure circadian rhythms contemporaneously with these natural/experimental factors. Actigraphic measures of circadian dysrhythmias are associated prospectively with the switch into high- or low-activation states, and more studies are needed to establish the most relevant prognostic actigraphy metrics in bipolar disorder. Interventions that can affect the circadian system (e.g., light therapy, lithium) can also reduce the switch into high-/low-activation states. Whether circadian rhythms mediate these clinical effects is an unknown but valuable question. The influence of age, sex, and other confounders on these associations needs to be better characterised.

CONCLUSION

Based on the reviewed evidence, our view is that circadian dysrhythmia is a plausible driver of transitions into high- and low-activation states and deserves prioritisation in research in bipolar disorders.

Lithium affects the circadian clock in the choroid plexus - A new role for an old mechanism

Lithium is an effective mood stabilizer, but the mechanism of its therapeutic action is not well understood. We investigated the effect of lithium on the circadian clock located in the ventricle barrier complex containing the choroid plexus (CP), a part of the glymphatic system that influences gross brain function via the production of cerebrospinal fluid. The mPer2^Luc mice were injected with lithium chloride (LiCl) or vehicle, and their effects on the clock gene Nr1d1 in CP were detected by RT qPCR. CP organotypic explants were prepared to monitor bioluminescence rhythms in real time and examine the responses of the CP clock to LiCl and inhibitors of glycogen synthase kinase-3 (CHIR-99021) and protein kinase C (chelerythrine). LiCl affected Nr1d1 expression levels in CP in vivo and dose-dependently delayed the phase and prolonged the period of the CP clock in vitro. LiCl and CHIR-99021 had different effects on 1] CP clock parameters (amplitude, period, phase), 2] dexamethasone-induced phase shifts of the CP clock, and 3] dynamics of PER2 degradation and de novo accumulation. LiCl-induced phase delays were significantly reduced by chelerythrine, suggesting the involvement of PKC activity. The effects on the CP clock may be involved in the therapeutic effects of lithium and hypothetically improve brain function in psychiatric patients by aligning the function of the CP clock-related glymphatic system with the sleep-wake cycle. Importantly, our data argue for personalized timing of lithium treatment in BD patients.

Mood and behavior regulation: interaction of lithium and dopaminergic system

Lithium is one of the most effect mood-stabilizing drugs prescribed especially for bipolar disorder. Lithium has wide range effects on different molecular factors and neural transmission including dopaminergic signaling. On the other hand, mesolimbic and mesocortical dopaminergic signaling is significantly involved in the pathophysiology of neuropsychiatric disorders. This review article aims to study lithium therapeutic mechanisms, dopaminergic signaling, and the interaction of lithium and dopamine. We concluded that acute and chronic lithium treatments often reduce dopamine synthesis and level in the brain. However, some studies have reported conflicting results following lithium treatment, especially chronic treatment. The dosage, duration, and type of lithium administration, and the brain region selected for measuring dopamine level were not significant differences in different chronic treatments used in previous studies. It was suggested that lithium has various mechanisms affecting dopaminergic signaling and mood, and that many molecular factors can be involved, including brain-derived neurotrophic factor (BDNF), cAMP response element-binding protein (CREB), β-catenin, protein kinase B (Akt), and glycogen synthase kinase-3 beta (GSK-3β). Thus, molecular effects of lithium can be the most important mechanisms of lithium that also alter neural transmissions including dopaminergic signaling in mesolimbic and mesocortical pathways.

Blood and cerebrospinal fluid biomarker changes in patients with HIV-associated neurocognitive impairment treated with lithium: analysis from a randomised placebo-controlled trial

HIV-associated neurocognitive disorders (HAND) persist in the era of antiretroviral therapy (ART). Thus, ART does not completely halt or reverse the pathological processes behind HAND. Adjuvant mitigating treatments are, therefore, prudent. Lithium treatment is known to promote neuronal brain-derived neurotrophic factors (BDNF). Lithium is also an inhibitor of glycogen synthase kinase-3 beta (GSK-3-β). We analyzed biomarkers obtained from participants in a randomized placebo-controlled trial of lithium in ART-treated individuals with moderate or severe HAND. We assayed markers at baseline and 24 weeks across several pathways hypothesized to be affected by HIV, inflammation, or degeneration. Investigated biomarkers included dopamine, BDNF, neurofilament light chain, and CD8 + lymphocyte activation (CD38 + HLADR +). Alzheimer's Disease (AD) biomarkers included soluble amyloid precursor protein alpha and beta (sAPPα/β), Aβ38, 40, 42, and ten other biomarkers validated as predictors of mild cognitive impairment and progression in previous studies. These include apolipoprotein C3, pre-albumin, α1-acid glycoprotein, α1-antitrypsin, PEDF, CC4, ICAM-1, RANTES, clusterin, and cystatin c. We recruited 61 participants (placebo = 31; lithium = 30). The age baseline mean was 40 (± 8.35) years and the median CD4 + T-cell count was 498 (IQR: 389-651) cells/μL. Biomarker concentrations between groups did not differ at baseline. However, both groups' blood dopamine levels decreased significantly after 24 weeks (adj. p < 002). No other marker was significantly different between groups, and we concluded that lithium did not confer neuroprotection following 24 weeks of treatment. However, the study was limited in duration and sample size.

Is lithium neuroprotective? An updated mechanistic illustrated review

Neurodegeneration is a pathological process characterized by progressive neuronal impairment, dysfunction, and loss due to mitochondrial dysfunction, oxidative stress, inflammation, and apoptosis. Many studies have shown that lithium protects against neurodegeneration. Herein, we summarize recent clinical and laboratory studies on the neuroprotective effects of lithium against neurodegeneration and its potential to modulate mitochondrial dysfunction, oxidative stress, inflammation, and apoptosis. Recent findings indicate that lithium regulates critical intracellular pathways such as phosphatidylinositol-3 (PI3)/protein kinase B (Akt)/glycogen synthase kinase-3 (GSK3β) and PI3/Akt/response element-binding protein (CREB)/brain-derived neurotrophic factor (BDNF). We queried PubMed, Web of Science, Scopus, Elsevier, and other related databases using search terms related to lithium and its neuroprotective effect in various neurodegenerative diseases and events from January 2000 to May 2022. We reviewed the major findings and mechanisms proposed for the effects of lithium. Lithium's neuroprotective potential against neural cell degeneration is mediated by inducing anti-inflammatory factors, antioxidant enzymes, and free radical scavengers to prevent mitochondrial dysfunction. Lithium effects are regulated by two essential pathways: PI3/Akt/GSK3β and PI3/Akt/CREB/BDNF. Lithium acts as a neuroprotective agent against neurodegeneration by preventing inflammation, oxidative stress, apoptosis, and mitochondrial dysfunction using PI3/Akt/GSK3β and PI3/Akt/CREB/BDNF signaling pathways.

Brain development after intrauterine exposure to lithium: A magnetic resonance imaging study in school-age children

OBJECTIVE

Lithium is often continued during pregnancy to reduce the risk of perinatal mood episodes for women with bipolar disorder. However, little is known about the effect of intrauterine lithium exposure on brain development. The aim of this study was to investigate brain structure in children after intrauterine exposure to lithium.

METHODS

Participants were offspring, aged 8-14 years, of women with a diagnosis of bipolar spectrum disorder. In total, 63 children participated in the study: 30 with and 33 without intrauterine exposure to lithium. Global brain volume outcomes and white matter integrity were assessed using structural MRI and diffusion tensor imaging, respectively. Primary outcomes were total brain, cortical and subcortical gray matter, cortical white matter, lateral ventricles, cerebellum, hippocampus and amygdala volumes, cortical thickness, cortical surface area and global fractional anisotropy, and mean diffusivity. To assess how our data compared to the general population, global brain volumes were compared to data from the Generation R study (N = 3243).

RESULTS

In our primary analyses, we found no statistically significant associations between intrauterine exposure to lithium and structural brain measures. There was a non-significant trend toward reduced subcortical gray matter volume. Compared to the general population, lithium-exposed children showed reduced subcortical gray and cortical white matter volumes.

CONCLUSION

We found no differences in brain structure between lithium-exposed and non-lithium-exposed children aged 8-14 years following correction for multiple testing. While a rare population to study, future and likely multi-site studies with larger datasets are required to validate and extend these initial findings.

Pharmacological Strategies for Bipolar Disorders in Acute Phases and Chronic Management with a Special Focus on Lithium, Valproic Acid, and Atypical Antipsychotics

Bipolar disorders (BDs) are a heterogeneous group of severe affective disorders generally described by the alternation of (hypo)manic, depressive, and mixed phases, with euthymic intervals of variable duration. BDs are burdened with high psychiatric and physical comorbidity, increased suicide risk and reduced life expectancy. In addition, BDs can progress into complicated forms (e.g., mixed states, rapid/irregular cycling), which are more difficult to treat and often require personalized pharmacological combinations. Mood stabilizers, particularly Lithium and Valproic acid (VPA), still represent the cornerstones of both acute and chronic pharmacotherapies of BDs. Lithium is the gold standard in BD-I and BDII with typical features, while VPA seems more effective for atypical forms (e.g., mixed-prevalence and rapid-cycling). However, despite appropriate mood stabilization, many patients show residual symptoms, and more than a half recur within 1-2 years, highlighting the need of additional strategies. Among these, the association of atypical antipsychotics (AAPs) with mood stabilizers is recurrent in the treatment of acute phases, but it is also being growingly explored in the maintenance pharmacotherapy. These combinations are clinically more aggressive and often needed in the acute phases, whereas simplifying pharmacotherapies to mood stabilizers only is preferable in the long-term, whenever possible. When mood stabilizers are not enough for maintenance treatment, Quetiapine and, less consistently, Aripiprazole have been proposed as the most advisable adjunctive strategies, for their safety and tolerability profiles. However, in view of the increased risk of serious adverse effects, a careful patient-centered balance between costs and benefits is mandatory.

Exploring the Hypothesis of a Schizophrenia and Bipolar Disorder Continuum: Biological, Genetic and Pharmacologic Data

Present time nosology has its roots in Kraepelin's demarcation of schizophrenia and bipolar disorder. However, accumulating evidence has shed light on several commonalities between the two disorders, and some authors have advocated for the consideration of a disease continuum. Here, we review previous genetic, biological and pharmacological findings that provide the basis for this conceptualization. There is a cross-disease heritability, and they share single-nucleotide polymorphisms in some common genes. EEG and imaging patterns have a number of similarities, namely reduced white matter integrity and abnormal connectivity. Dopamine, serotonin, GABA and glutamate systems have dysfunctional features, some of which are identical among the disorders. Finally, cellular calcium regulation and mitochondrial function are, also, impaired in the two.

Chronic lithium treatment ameliorates ketamine-induced mania-like behavior via the PI3K-AKT signaling pathway

Ketamine, a rapid-acting antidepressant drug, has been used to treat major depressive disorder and bipolar disorder (BD). Recent studies have shown that ketamine may increase the potential risk of treatment-induced mania in patients. Ketamine has also been applied to establish animal models of mania. At present, however, the underlying mechanism is still unclear. In the current study, we found that chronic lithium exposure attenuated ketamine-induced mania-like behavior and c-Fos expression in the medial prefrontal cortex (mPFC) of adult male mice. Transcriptome sequencing was performed to determine the effect of lithium administration on the transcriptome of the PFC in ketamine-treated mice, showing inactivation of the phosphoinositide 3-kinase (PI3K)-protein kinase B (AKT) signaling pathway. Pharmacological inhibition of AKT signaling by MK2206 (40 mg/kg), a selective AKT inhibitor, reversed ketamine-induced mania. Furthermore, selective knockdown of AKT via AAV-AKT-shRNA-EGFP in the mPFC also reversed ketamine-induced mania-like behavior. Importantly, pharmacological activation of AKT signaling by SC79 (40 mg/kg), an AKT activator, contributed to mania in low-dose ketamine-treated mice. Inhibition of PI3K signaling by LY294002 (25 mg/kg), a specific PI3K inhibitor, reversed the mania-like behavior in ketamine-treated mice. However, pharmacological inhibition of mammalian target of rapamycin (mTOR) signaling with rapamycin (10 mg/kg), a specific mTOR inhibitor, had no effect on ketamine-induced mania-like behavior. These results suggest that chronic lithium treatment ameliorates ketamine-induced mania-like behavior via the PI3K-AKT signaling pathway, which may be a novel target for the development of BD treatment.

Mental health progress requires causal diagnostic nosology and scalable causal discovery

Nine hundred and seventy million individuals across the globe are estimated to carry the burden of a mental disorder. Limited progress has been achieved in alleviating this burden over decades of effort, compared to progress achieved for many other medical disorders. Progress on outcome improvement for all medical disorders, including mental disorders, requires research capable of discovering causality at sufficient scale and speed, and a diagnostic nosology capable of encoding the causal knowledge that is discovered. Accordingly, the field's guiding paradigm limits progress by maintaining: (a) a diagnostic nosology (DSM-5) with a profound lack of causality; (b) a misalignment between mental health etiologic research and nosology; (c) an over-reliance on clinical trials beyond their capabilities; and (d) a limited adoption of newer methods capable of discovering the complex etiology of mental disorders. We detail feasible directions forward, to achieve greater levels of progress on improving outcomes for mental disorders, by: (a) the discovery of knowledge on the complex etiology of mental disorders with application of Causal Data Science methods; and (b) the encoding of the etiological knowledge that is discovered within a causal diagnostic system for mental disorders.

Second messengers and their importance for novel drug treatments of patients with bipolar disorder

Second messenger systems, like the cyclic nucleotide, glycogen synthase kinase-3β, phosphoinositide, and arachidonic acid cascades, are involved in bipolar disorder (BD). We investigated their role on the development of novel therapeutic drugs using second messenger mechanisms. PubMed search and narrative review. We used all relevant keywords for each second messenger cascade combining it with BD and related terms and combined all with novel/innovative treatments/drugs. Our search produced 31 papers most were reviews, and focussed on the PI3K/AKT-GSK-3β/Nrf2-NF-ĸB pathways. Only two human randomized clinical trials were identified, of ebselen, an antioxidant, and celecoxib, a cyclooxygenase-2 inhibitor, both with poor unsatisfactory results. Despite the fact that all second messenger systems are involved in the pathophysiology of BD, there are few experiments with novel drugs using these mechanisms. These mechanisms are a neglected and potentially major opportunity to transform the treatment of bipolar illness.

Transcriptomics and miRNomics data integration in lymphoblastoid cells highlights the key role of immune-related functions in lithium treatment response in Bipolar disorder

BACKGROUND

Bipolar Disorder (BD) is a complex mental disease characterized by recurrent episodes of mania and depression. Lithium (Li) represents the mainstay of BD pharmacotherapy, despite the narrow therapeutic index and the high variability in treatment response. However, although several studies have been conducted, the molecular mechanisms underlying Li therapeutic effects remain unclear.

METHODS

In order to identify molecular signatures and biological pathways associated with Li treatment response, we conducted transcriptome and miRNome microarray analyses on lymphoblastoid cell lines (LCLs) from 20 patients diagnosed with BD classified as Li responders (n = 11) or non-responders (n = 9).

RESULTS

We found 335 mRNAs and 77 microRNAs (miRNAs) significantly modulated in BD responders versus non-responders. Interestingly, pathway and network analyses on these differentially expressed molecules suggested a modulatory effect of Li on several immune-related functions. Indeed, among the functional molecular nodes, we found NF-κB and TNF. Moreover, networks related to these molecules resulted overall inhibited in BD responder patients, suggesting anti-inflammatory properties of Li. From the integrative analysis between transcriptomics and miRNomics data carried out using miRComb R package on the same samples from patients diagnosed with BD, we found 97 significantly and negatively correlated mRNA-miRNA pairs, mainly involved in inflammatory/immune response.

CONCLUSIONS

Our results highlight that Li exerts modulatory effects on immune-related functions and that epigenetic mechanisms, especially miRNAs, can influence the modulation of different genes and pathways involved in Li response. Moreover, our data suggest the potentiality to integrate data coming from different high-throughput approaches as a tool to prioritize genes and pathways.

Relationship between lithium carbonate and the risk of Parkinson-like events in patients with bipolar disorders: A multivariate analysis using the Japanese adverse drug event report database

The present study attempted to identify risk factors for Parkinson-like events using the Japanese adverse drug event report database. A total of 3521 patients with bipolar disorders were extracted from the database, and Parkinson-like events were detected in 111 (3.15%) using the standardized Medical Dictionary for Regulatory Activities queries. A multiple logistic regression analysis identified age ≥50 years and the use of sodium valproate or aripiprazole as risk factors. Lithium carbonate was not associated with an increased risk of Parkinson-like events, but was related to these events in patients taking sodium valproate.

Patient with bipolar I disorder who presented with low blood lithium levels after receiving crushed tablets via a nasogastric tube: A case report

In clinical psychiatric cases, the placement of a nasogastric tube is occasionally considered. If a patient who presents with mania or other psychiatric conditions refuses to take drugs, they are administered via the nasogastric tube. The tablet is crushed, suspended, passed via the nasogastric line, and reaches the stomach directly. However, the effects of these processes on blood drug concentrations remain unclear. Herein, we report a patient with bipolar I disorder who presented with low blood lithium carbonate (Li) concentrations after receiving the drug via the nasogastric tube.

CASE

A 26-year-old woman developed manic symptoms with grandeur delusion. She was admitted to a psychiatric hospital three times after diagnosis. Her manic symptoms with delusion improved with Li and aripiprazole (ARP). Her condition stabilized with Li 800 mg/day and ARP 9 mg/day. After the Li dose was reduced to 600 mg/day, she maintained remission, with the blood level range of Li being 0.31 ∼ 0.42 mEq/L. After 1 year, she was admitted to our hospital due to a jaw deformity. During the perioperative period, treatment with oral Li was discontinued by the surgeons, and her manic symptoms recurred. During therapy with olanzapine 20 mg and Li 800 mg, her blood Li concentration was 0.67 mEq/L. The symptoms remained. Hence, the Li dose increased to 1,000 mg/day. However, she refused to take the medication. Thus, a nasogastric tube was used to administer medicines. Thereafter, the blood Li concentration decreased to 0.43 mEq/L, which was lesser than 800 mg/day. Each blood sample was collected approximately 18 h after the administration. Her symptoms remained. Thereafter, she agreed to take the medication, and the Li concentration reached 0.78 mEq/L. Then, the symptoms partly improved.

CONCLUSION

After the administration of Li via the nasogastric tube, the Li concentration decreased, which was lower than expected. This phenomenon could be attributed to the fact that the medication was crushed, suspended, and administered via the nasogastric tube. Therefore, pulverizing and administering Li tablets via the nasogastric tube can be applied for the management of mania, however, caution should be observed because of the risk of fluctuations in blood Li levels, as in this case.

Lithium effects on Hippocampus volumes in patients with bipolar disorder

BACKGROUND

Lithium is one of the most effective medications for bipolar disorder episode prevention, but its mechanism of action is still largely unknown. The hippocampus is a subcortical cerebral structure involved in the formation of emotional responses, cognition and various primitive functions, altered during affective episodes. Deviations in the anatomy or physiology of the hippocampus would partially explain the symptomatology of bipolar subjects, and restoration may reflect treatment response.

METHODS

In this mini review, we summarize the studies which have investigated the effect of lithium intake on the volume of hippocampus, measured using magnetic resonance imaging (MRI). We performed a bibliographic search on PubMed, using the terms terms "hippocampus", "lithium", "bipolar disorder", "volume" and "MRI". Only original studies were considered.

RESULTS

Thirteen studies met the inclusion criteria. Nine studies demonstrated increased total hippocampal volume or hippocampal subfield volumes in BD patients on lithium treatment (Li BD) compared to those not taking lithium (non-Li BD), while four failed to show significant differences between groups. When healthy controls were compared to either the Li subjects or the non-Li ones, the findings were more heterogeneous.

LIMITATIONS

Heterogeneity in the methodology and definition of groups limits the comparison of study results.

CONCLUSIONS

Lithium may be associated with increased hippocampal volume in BD, potentially due to its putative neurotrophic action, but further research is needed better define the morphological alterations of hippocampus in BD and the longitudinal effects of lithium in the short and long-term.

Duration of untreated illness and bipolar disorder: time for a new definition? Results from a cross-sectional study

BACKGROUND

We primarily aimed to explore the associations between duration of untreated illness (DUI), treatment response, and functioning in a cohort of patients with bipolar disorder (BD).

METHODS

261 participants with BD were recruited. DUI was defined as months from the first affective episode to the start of a mood-stabilizer. The functioning assessment short test (FAST) scores and treatment response scores for lithium, valproate, or lamotrigine according to the Alda Scale Total Score (TS) were compared between patients with short (<24 months) or long DUI. Differences in FAST scores among good (GR; TS≥7), poor (PR; TS=2-6), or non-responders (NR; TS<2) to each mood-stabilizer were analyzed. Linear regression was computed using the FAST global score as the dependent variable.

RESULTS

DUI and FAST scores showed no statistically significant correlation. Patients with a longer DUI showed poorer response to lithium (Z=-3.196; p<0.001), but not to valproate or lamotrigine. Response to lithium (β=-1.814; p<0.001), number of hospitalizations (β=0.237; p<0.001), and illness duration (β=0.160; p=0.028) were associated with FAST total scores. GR to lithium was associated with better global functioning compared to PR or NR [H=27.631; p<0.001].

LIMITATIONS

The retrospective design could expose our data to a recall bias. Also, only few patients were on valproate or lamotrigine treatment.

CONCLUSIONS

Poor functioning in BD could be the result of multiple affective relapses, rather than a direct effect of DUI. A timely diagnosis with subsequent effective prophylactic treatment, such as lithium, may prevent poor functional outcomes in real-world patients with BD.

Patient fibroblast circadian rhythms predict lithium sensitivity in bipolar disorder

Bipolar disorder is a chronic neuropsychiatric condition associated with mood instability, where patients present significant sleep and circadian rhythm abnormalities. Currently, the pathophysiology of bipolar disorder remains elusive, but treatment with lithium continues as the benchmark pharmacotherapy, functioning as a potent mood stabilizer in most, but not all patients. Lithium is well documented to induce period lengthening and amplitude enhancement of the circadian clock. Based on this, we sought to investigate whether lithium differentially impacts circadian rhythms in bipolar patient cell lines and crucially if lithium's effect on the clock is fundamental to its mood-stabilizing effects. We analyzed the circadian rhythms of bipolar patient-derived fibroblasts (n = 39) and their responses to lithium and three further chronomodulators. Here we show, relative to controls (n = 23), patients exhibited a wider distribution of circadian period (p < 0.05), and that patients with longer periods were medicated with a wider range of drugs, suggesting lower effectiveness of lithium. In agreement, patient fibroblasts with longer periods displayed muted circadian responses to lithium as well as to other chronomodulators that phenocopy lithium. These results show that lithium differentially impacts the circadian system in a patient-specific manner and its effect is dependent on the patient's circadian phenotype. We also found that lithium-induced behavioral changes in mice were phenocopied by modulation of the circadian system with drugs that target the clock, and that a dysfunctional clock ablates this response. Thus, chronomodulatory compounds offer a promising route to a novel treatment paradigm. These findings, upon larger-scale validation, could facilitate the implementation of a personalized approach for mood stabilization.

Trinuclear Calcium Site in the C2 Domain of PKCα/γ Is Prone to Lithium Attack

Lithium (Li⁺) is the first-line therapy for bipolar disorder and a candidate drug for various diseases such as amyotrophic lateral sclerosis, multiple sclerosis, and stroke. Despite being the captivating subject of many studies, the mechanism of lithium's therapeutic action remains unclear. To date, it has been shown that Li⁺ competes with Mg²⁺ and Na⁺ to normalize the activity of inositol and neurotransmitter-related signaling proteins, respectively. Furthermore, Li⁺ may co-bind with Mg²⁺-loaded adenosine or guanosine triphosphate to alter the complex's susceptibility to hydrolysis and mediate cellular signaling. Bipolar disorder patients exhibit abnormally high cytosolic Ca²⁺ levels and protein kinase C (PKC) hyperactivity that can be downregulated by long-term Li⁺ treatment. However, the possibility that monovalent Li⁺ could displace the bulkier divalent Ca²⁺ and inhibit PKC activity has not been considered. Here, using density functional theory calculations combined with continuum dielectric methods, we show that Li⁺ may displace the native dication from the positively charged trinuclear site in the C2 domain of cytosolic PKCα/γ. This would affect the membrane-docking ability of cytosolic PKCα/γ and reduce the abnormally high membrane-associated active PKCα/γ levels, thus downregulating the PKC hyperactivity found in bipolar patients.

Deletion or inhibition of prolyl oligopeptidase blocks lithium-induced phosphorylation of GSK3b and Akt by activation of protein phosphatase 2A

Alterations in prolyl oligopeptidase (PREP) activity have been connected, for example, with bipolar and major depressive disorder, and several studies have reported that lack or inhibition of PREP blocks the effects of lithium on inositol 1,4,5-triphosphate (IP₃ ) levels. However, the impact of PREP modulation on other intracellular targets of lithium, such as glycogen synthase kinase 3 beta (GSK3b) or protein kinase B (Akt), has not been studied. We recently found that PREP regulates protein phosphatase 2A (PP2A), and because GSK3b and Akt are PP2A substrates, we studied if PREP-related lithium insensitivity is dependent on PP2A. To assess this, HEK-293 and SH-SY5Y cells with PREP deletion or PREP inhibition (KYP-2047) were exposed to lithium, and thereafter, the phosphorylation levels of GSK3b and Akt were measured by Western blot. As expected, PREP deletion and inhibition blocked the lithium-induced phosphorylation on GSK3b and Akt in both cell lines. When lithium exposure was combined with okadaic acid, a PP2A inhibitor, KYP-2047 did not have effect on lithium-induced GSK3b and Akt phosphorylation. Therefore, we conclude that PREP deletion or inhibition blocks the intracellular effects of lithium on GSK3b and Akt via PP2A activation.

RNA therapeutics for mood disorders: current evidence toward clinical trials

INTRODUCTION

Mood disorders are severe yet frequent psychiatric disorders worldwide, comprising major depressive disorder (MDD) and bipolar disorders (BD). Their treatment remains poorly effective. Recently, growing evidence for epigenetic mechanisms has emerged. Consequently, a great interest in a novel pharmacological class arose: RNA therapeutics.

AREAS COVERED

We conducted a systematic review of RNA therapeutics -antisense oligonucleotides (ASOs), small interfering RNAs (siRNAs), short hairpin RNAs (shRNAs), and micro-RNA (miRNA) therapeutics- for the treatment of mood disorders studied in pre-clinical animal models listed in PubMed, in clinical trials registered in ClinicalTrials.gov and available on the market by combining literature search and Food and Drug Administration and European Medicine Agency online databases. Eighteen pre-clinical studies investigated the antidepressant effects of RNA therapeutics. However, even though there is an increasing number of marketing authorizations and clinical trials for the past twenty years, no RNA therapeutic has reached the clinical development pipeline for the treatment of psychiatric disorders yet.

EXPERT OPINION

Several promising RNA therapeutics have been tested in pre-clinical studies for MDD, whereas no molecule has been developed for BD. There are several issues to address before reaching clinical development and new challenges include stratifying patient population and predicting therapeutic response.

When Good Kinases Go Rogue: GSK3, p38 MAPK and CDKs as Therapeutic Targets for Alzheimer's and Huntington's Disease

Alzheimer's disease (AD) is a mostly sporadic brain disorder characterized by cognitive decline resulting from selective neurodegeneration in the hippocampus and cerebral cortex whereas Huntington's disease (HD) is a monogenic inherited disorder characterized by motor abnormalities and psychiatric disturbances resulting from selective neurodegeneration in the striatum. Although there have been numerous clinical trials for these diseases, they have been unsuccessful. Research conducted over the past three decades by a large number of laboratories has demonstrated that abnormal actions of common kinases play a key role in the pathogenesis of both AD and HD as well as several other neurodegenerative diseases. Prominent among these kinases are glycogen synthase kinase (GSK3), p38 mitogen-activated protein kinase (MAPK) and some of the cyclin-dependent kinases (CDKs). After a brief summary of the molecular and cell biology of AD and HD this review covers what is known about the role of these three groups of kinases in the brain and in the pathogenesis of the two neurodegenerative disorders. The potential of targeting GSK3, p38 MAPK and CDKS as effective therapeutics is also discussed as is a brief discussion on the utilization of recently developed drugs that simultaneously target two or all three of these groups of kinases. Multi-kinase inhibitors either by themselves or in combination with strategies currently being used such as immunotherapy or secretase inhibitors for AD and knockdown for HD could represent a more effective therapeutic approach for these fatal neurodegenerative diseases.

Position sensitive measurement of trace lithium in the brain with NIK (neutron-induced coincidence method) in suicide

Mood disorder is the leading intrinsic risk factor for suicidal ideation. Questioning any potency of mood-stabilizers, the monovalent cation lithium still holds the throne in medical psychiatric treatment. Furthermore, lithium`s anti-aggressive and suicide-preventive capacity in clinical practice is well established. But little is still known about trace lithium distribution and any associated metabolic effects in the human body. We applied a new technique (neutron-induced coincidence method “NIK”) utilizing the ⁶Li(n,α)³H reaction for the position sensitive, 3D spatially resolved detection of lithium traces in post-mortem human brain tissue in suicide versus control. NIK allowed, for the first time in lithium research, to collect a three dimensional high resolution map of the regional trace lithium content in the non lithium-medicated human brain. The results show an anisotropic distribution of lithium, thus indicating a homeostatic regulation under physiological conditions as a remarkable link to essentiality. In contrast to suicide we could empirically prove significantly higher endogenous lithium concentrations in white compared to gray matter as a general trend in non-suicidal individuals and lower lithium concentrations in emotion-modulating regions in suicide.

The association between lithium in drinking water and neuropsychiatric outcomes: A systematic review and meta-analysis from across 2678 regions containing 113 million people

BACKGROUND

Lithium in drinking water may have significant mental health benefits. We investigated the evidence on the association between lithium concentrations in drinking water and their neuropsychiatric outcomes.

METHODS

We conducted a systematic review and meta-analysis and searched Pubmed, Embase, Web of Science, PsycINFO and CINAHL up to 19 January 2020, for peer-reviewed research examining the association between lithium concentrations in drinking water and neuropsychiatric outcomes. We used a pairwise analysis and a random effects model to meta-analyse suicide rates and psychiatric hospital admissions. We assessed for publication bias using Egger's test and Duval and Tweedie's Trim and Fill analysis.

RESULTS

Twenty-seven studies including 113 million subjects were included in this systematic review. Meta-analysis of 14 studies including 94 million people found higher lithium concentrations were associated with reduced suicide rates (r = -0.191, 95% confidence interval = [-0.287, -0.090], p < 0.001) and meta-analysis of two studies including 5 million people found higher lithium concentrations were associated with fewer hospital admissions (r = -0.413, 95% confidence interval = [-0.689, -0.031], p = 0.035). We found significant heterogeneity between studies (Q = 67.4, p < 0.001, I² = 80.7%) and the presence of publication bias (Egger's test; t value = 2.90, p = 0.013). Other included studies did not provide sufficient data to analyse other neuropsychiatric outcomes quantitatively.

CONCLUSION

Higher lithium concentrations in drinking water may be associated with reduced suicide rates and inpatient psychiatric admissions. The relationship with other neuropsychiatric outcomes and complications remains unclear. Further research is required before any public health recommendations can be made.Trial registration number: The study was registered with PROSPERO, number CRD42018090145.

Respiratory infections during lithium and valproate medication: a within-individual prospective study of 50,000 patients with bipolar disorder

BACKGROUND

In vitro studies have demonstrated that lithium has antiviral properties, but evidence from human studies is scarce. Lithium is used as a mood stabilizer to treat patients with bipolar disorder. Here, the aim was to investigate the association between lithium use and the risk of respiratory infections in patients with bipolar disorder. To rule out the possibility that a potential association could be due to lithium's effect on psychiatric symptoms, we also studied the effect of valproate, which is an alternative to lithium used to prevent mood episodes in bipolar disorder.

METHOD

We followed 51,509 individuals diagnosed with bipolar disorder in the Swedish Patient register 2005-2013. We applied a within-individual design using stratified Cox regression to estimate the hazard ratios (HRs) of respiratory infections during treated periods compared with untreated periods.

RESULTS

During follow-up, 5,760 respiratory infections were documented in the Swedish Patient Register. The incidence rate was 28% lower during lithium treatment (HR 0.73, 95% CI 0.61-0.86) and 35% higher during valproate treatment (HR 1.35, 95% CI 1.06-1.73) compared with periods off treatment.

CONCLUSIONS

This study provides real-world evidence that lithium is associated with decreased risk for respiratory infections and suggests that the repurposing potential of lithium for potential antiviral or antibacterial effects is worthy of investigation.

The Impact of Lithium on Brain Function in Bipolar Disorder: An Updated Review of Functional Magnetic Resonance Imaging Studies

Lithium remains a gold standard treatment for bipolar disorder (BD), and functional magnetic resonance imaging (fMRI) studies have contributed to clarifying its impact on neural circuitries in affected individuals. However, the specific neurobiological mechanisms through which lithium exerts its effects on brain function are not fully understood. In this review, we aimed to summarize the results of recent fMRI studies evaluating the impact of lithium on brain functional activity and connectivity in patients diagnosed with BD. We performed a literature search of available sources found in the PubMed database reported in English since 2016, when the last available review on this topic was published. Five fMRI studies in resting-state condition and six studies performed during the execution of emotional tasks met the inclusion criteria. Overall, the available evidence supports normalizing effects of lithium on brain activity and connectivity. Most of these studies reported a normalization in prefrontal regions and interconnected areas involved in emotion regulation and processing, regardless of the task employed. Importantly, lithium treatment showed distinct patterns of activity/connectivity changes compared with other treatments. Finally, lithium modulation of neural circuitries was found to be associated with clinical improvement in BD. These results are consistent with the hypothesis that selective abnormalities in neural circuitries supporting emotion processing and regulation improve during lithium treatment in BD. However, the heterogeneity of the examined studies regarding study design, sample selection, and analysis methods might limit the generalizability of the findings and lead to difficulties in comparing the results. Therefore, in future studies, larger cohorts and homogeneous experimental tasks are needed to further corroborate these findings.

[Lithium in the psychopharmacology of affective disorders and mechanisms of its effects on cellular physiology]

However, despite successful use of lithium in the treatment of affective disorders for almost 40 years, the mechanisms of its therapeutic action are still poorly understood. This review presents and summarizes the current literature about the use of lithium in treatment of affective disorders, as well as its effects on cellular physiology, with a separate description of the effect of this ion on the functioning of nerve tissue and ion-molecular mechanisms.

Beyond the Mind-Serum Trace Element Levels in Schizophrenic Patients: A Systematic Review

The alterations in serum trace element levels are common phenomena observed in patients with different psychiatric conditions such as schizophrenia, autism spectrum disorder, or major depressive disorder. The fluctuations in the trace element concentrations might act as potential diagnostic and prognostic biomarkers of many psychiatric and neurological disorders. This paper aimed to assess the alterations in serum trace element concentrations in patients with a diagnosed schizophrenia. The authors made a systematic review, extracting papers from the PubMed, Web of Science, and Scopus databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Among 5009 articles identified through database searching, 59 of them were assessed for eligibility. Ultimately, 33 articles were included in the qualitative synthesis. This review includes the analysis of serum levels of the following trace elements: iron, nickel, molybdenum, phosphorus, lead, chromium, antimony, uranium, magnesium, aluminum, zinc, copper, selenium, calcium, and manganese. Currently, there is no consistency regarding serum trace element levels in schizophrenic patients. Thus, it cannot be considered as a reliable prognostic or diagnostic marker of schizophrenia. However, it can be assumed that altered concentrations of those elements are crucial regarding the onset and exaggeration of either psychotic or negative symptoms or cognitive dysfunctions.