Lithium specificity in bipolar illness: a classic agent for the classic disorder

The anti-inflammation pharmacodynamics of lithium: Therapy of bipolar disorder

Bipolar disorder is a severe mental disorder that necessitates effective long-term treatment strategies. Clinically, lithium has demonstrated favorable outcomes in managing this condition. The inflammatory theory posits that bipolar disorder is influenced by an inflammatory response, and lithium is thought to mitigate this disorder by inhibiting such responses. In terms of the pharmacodynamics of blocking inflammatory mediators, lithium mainly acts on GSK-3β. Upon interaction with GSK-3β, lithium can suppress the gene expression of inflammatory mediators, subsequently reducing their secretion. This mechanism influences multiple downstream pathways, ultimately contributing to the therapeutic effects observed in bipolar disorder. Specifically, these pathways include the arachidonic acid pathway, nitric oxide synthase pathway, neurotransmitter pathway, and so on. This article reviews the pharmacodynamic targets and mechanisms of lithium, offering insights into the appropriate clinical application of lithium and the advancement of lithium pharmacotherapies.

Prior psychiatric morbidity and differential psychopharmacological treatment patterns: Exploring the heterogeneity of bipolar disorder in a nationwide study of 9594 patients

OBJECTIVES

Individuals with bipolar disorders (BD) have heterogenic pre-onset illness courses and responses to treatment. The pattern of illness preceding the diagnosis of BD may be a marker of future treatment response. Here, we examined associations between psychiatric morbidity preceding the diagnosis of BD and pharmacological treatment patterns in the 2 years following diagnosis.

METHODS

In this register-based study, we included all patients with a diagnosis of BD attending Danish Psychiatric Services between January 1, 2012 and December 31, 2016. We examined the association between a diagnosis of substance use disorder, psychosis (other than schizophrenia or schizoaffective disorder), unipolar depression, anxiety/OCD, PTSD, personality disorder, or ADHD preceding BD and pharmacological treatment patterns following the diagnosis of BD (lithium, valproate, lamotrigine, antidepressants, olanzapine, risperidone, and quetiapine) via multivariable Cox proportional hazards regression adjusted for age, sex, and year of BD diagnosis.

RESULTS

We included 9594 patients with a median age of 39 years, 58% of whom were female. Antidepressants, quetiapine, and lamotrigine were the most commonly used medications in BD and were all linked to prior depressive illness and female sex. Lithium was used among patients with less diagnostic heterogeneity preceding BD, while valproate was more likely to be used for patients with prior substance use disorder or ADHD.

CONCLUSION

The pharmacological treatment of BD is linked to psychiatric morbidity preceding its diagnosis. Assuming that these associations reflect well-informed clinical decisions, this knowledge may inform future clinical trials by taking participants' prior morbidity into account in treatment allocation.

Countering the declining use of lithium therapy: a call to arms

For over half a century, it has been widely known that lithium is the most efficacious treatment for bipolar disorder. Yet, despite this, its prescription has consistently declined over this same period of time. A number of reasons for this apparent disparity between evidence and clinical practice have been proposed, including a lack of confidence amongst clinicians possibly because of an absence of training and lack of familiarity with the molecule. Simultaneously, competition has grown within the pharmacological armamentarium for bipolar disorder with newer treatments promoting an image of being safer and easier to prescribe primarily because of not necessitating plasma monitoring, which understandably is appealing to patients who then exercise their preferences accordingly. However, these somewhat incipient agents are yet to reach the standard lithium has attained in terms of its efficacy in providing prophylaxis against the seemingly inevitable recrudescence of acute episodes that punctuates the course of bipolar disorder. In addition, none of these mimics have the additional benefits of preventing suicide and perhaps providing neuroprotection. Thus, a change in strategy is urgently required, wherein myths regarding the supposed difficulties in prescribing lithium and the gravity of its side-effects are resolutely dispelled. It is this cause to which we have pledged our allegiance and it is to this end that we have penned this article.

Why lithium should be used in patients with bipolar disorder? A scoping review and an expert opinion paper

INTRODUCTION

Lithium treatment is considered the gold standard for the long-term management of bipolar disorder and recurrent unipolar depression. It is also extremely effective in other psychiatric conditions characterized by impulsivity and aggression, and for the prevention of suicidal behaviours.

AREAS COVERED

This paper provides a scoping review and an expert commentary regarding the use of lithium in adult patients. Available information about efficacy, tolerability, dosing, and switching is analyzed, and the strategies that may be most useful in real-world clinical settings are highlighted.

EXPERT OPINION

Lithium is effective on different domains of bipolar disorder, including the long-term prevention of recurrences of affective episodes, management of acute mania as well as in the prophylaxis of all affective episodes. Lithium has been defined a 'forgotten drug,' since its use in routine clinical practice has been declined over the last 20 or 30 years. Reasons for this trend include lack of adequate training on the management of lithium side effects. Considering its efficacy, use of lithium in ordinary clinical practice should be promoted. Several strategies, such as using slow-release formulations, can be easily implemented in order to minimize lithium side effects and improve its tolerability profile.

A critical evaluation of dynamical systems models of bipolar disorder

Bipolar disorder (BD) is a mood disorder involving recurring (hypo)manic and depressive episodes. The inherently temporal nature of BD has inspired its conceptualization using dynamical systems theory, which is a mathematical framework for understanding systems that evolve over time. In this paper, we provide a critical review of the dynamical systems models of BD. Owing to the heterogeneity of methodological and experimental designs in computational modeling, we designed a structured approach that parallels the appraisal of animal models by their face, predictive, and construct validity. This tool, the validity appraisal guide for computational models (VAG-CM), is not an absolute measure of validity, but rather a guide for a more objective appraisal of models in this review. We identified 26 studies published before November 18, 2021 that proposed generative dynamical systems models of time-varying signals in BD. Two raters independently applied the VAG-CM to the included studies, obtaining a mean Cohen's κ of 0.55 (95% CI [0.45, 0.64]) prior to establishing consensus ratings. Consensus VAG-CM ratings revealed three model/study clusters: data-driven models with face validity, theory-driven models with predictive validity, and theory-driven models lacking all forms of validity. We conclude that future modeling studies should employ a hybrid approach that first operationalizes BD features of interest using empirical data to achieve face validity, followed by explanations of those features using generative models with components that are homologous to physiological or psychological systems involved in BD, to achieve construct validity. Such models would be best developed alongside long-term prospective cohort studies involving a collection of multimodal time-series data. We also encourage future studies to extend, modify, and evaluate the VAG-CM approach for a wider breadth of computational modeling studies and psychiatric disorders.

Thing one and thing two1: What 'Doctors use' to doctor you?

This perspective piece is a detailed analysis of the critique by Gordon Parker of the mood disorders clinical practice guidelines (MDcpg²⁰²⁰), in which he claims that bipolar II disorder has been 'banished' despite its formal status in current taxonomies. In this article, I defend the reasoning used by the Committee to adopt a dimensional model for describing and managing mood disorders, in particular bipolar disorder. I also robustly contend the many erroneous inferences made by him in his Viewpoint regarding management recommendations within the MDcpg²⁰²⁰ and demonstrate that there is no valid justification for subtyping bipolar disorder - especially in the manner proposed by the Diagnostic and Statistical Manual of Mental Disorders, 5th edition. Thus, I argue that it was appropriate for the MDcpg²⁰²⁰ Committee to pursue an alternative model to the usual subtyping of bipolar disorder into 'thing one' and 'thing two' and conclude that the now clearly redundant model of Bipolar II should be altogether removed from our lexicon and clinical practice. Indeed, it is time to develop new and alternative models for defining bipolar disorder and among these a dimensional model should be given consideration.

Prediction of lithium response using genomic data

Predicting lithium response prior to treatment could both expedite therapy and avoid exposure to side effects. Since lithium responsiveness may be heritable, its predictability based on genomic data is of interest. We thus evaluate the degree to which lithium response can be predicted with a machine learning (ML) approach using genomic data. Using the largest existing genomic dataset in the lithium response literature (n = 2210 across 14 international sites; 29% responders), we evaluated the degree to which lithium response could be predicted based on 47,465 genotyped single nucleotide polymorphisms using a supervised ML approach. Under appropriate cross-validation procedures, lithium response could be predicted to above-chance levels in two constituent sites (Halifax, Cohen’s kappa 0.15, 95% confidence interval, CI [0.07, 0.24]; and Würzburg, kappa 0.2 [0.1, 0.3]). Variants with shared importance in these models showed over-representation of postsynaptic membrane related genes. Lithium response was not predictable in the pooled dataset (kappa 0.02 [− 0.01, 0.04]), although non-trivial performance was achieved within a restricted dataset including only those patients followed prospectively (kappa 0.09 [0.04, 0.14]). Genomic classification of lithium response remains a promising but difficult task. Classification performance could potentially be improved by further harmonization of data collection procedures.

Exemplar scoring identifies genetically separable phenotypes of lithium responsive bipolar disorder

Predicting lithium response (LiR) in bipolar disorder (BD) may inform treatment planning, but phenotypic heterogeneity complicates discovery of genomic markers. We hypothesized that patients with "exemplary phenotypes"-those whose clinical features are reliably associated with LiR and non-response (LiNR)-are more genetically separable than those with less exemplary phenotypes. Using clinical data collected from people with BD (n = 1266 across 7 centers; 34.7% responders), we computed a "clinical exemplar score," which measures the degree to which a subject's clinical phenotype is reliably predictive of LiR/LiNR. For patients whose genotypes were available (n = 321), we evaluated whether a subgroup of responders/non-responders with the top 25% of clinical exemplar scores (the "best clinical exemplars") were more accurately classified based on genetic data, compared to a subgroup with the lowest 25% of clinical exemplar scores (the "poor clinical exemplars"). On average, the best clinical exemplars of LiR had a later illness onset, completely episodic clinical course, absence of rapid cycling and psychosis, and few psychiatric comorbidities. The best clinical exemplars of LiR and LiNR were genetically separable with an area under the receiver operating characteristic curve of 0.88 (IQR [0.83, 0.98]), compared to 0.66 [0.61, 0.80] (p = 0.0032) among poor clinical exemplars. Variants in the Alzheimer's amyloid-secretase pathway, along with G-protein-coupled receptor, muscarinic acetylcholine, and histamine H1R signaling pathways were informative predictors. This study must be replicated on larger samples and extended to predict response to other mood stabilizers.

Seasonal and temperature effect on serum lithium concentrations

BACKGROUND

Lithium remains the gold standard treatment for bipolar disorder. However, it has a very narrow therapeutic index (0.6-0.8 mmol/L). It has been suggested that high environmental temperature can lead to dehydration, elevated plasma lithium concentration and then lithium toxicity.

OBJECTIVES

We aimed to investigate the effect of seasonal and short-term changes in temperature on serum lithium concentrations in Sydney, Australia.

METHODS

We retrospectively analysed data from all patients who had serum lithium concentrations taken from the Prince of Wales and Sutherland Hospitals between 2008 and 2018. Temperature data came from the Bureau of Meteorology. We examined correlations between lithium concentrations and the preceding 5 days maximum temperatures, month and season. We also performed a longitudinal analysis of the effect of temperature and seasons within selected patients who had repeated levels.

RESULTS

A total of 11,912 serum lithium concentrations from 2493 patients were analysed. There was no significant association between higher lithium concentration and preceding higher temperatures (r = -0.008, p = 0.399). There was also no important seasonal or monthly variation, across all patients or in the smaller cohort with longitudinal data (n = 123, r = 0.008, 95% confidence interval: [-0.04, 0.06]).

CONCLUSION

There were no clinically important differences in serum lithium concentration related to seasons, months or temperatures, which suggests that patients on lithium are able to adequately maintain hydration during hot weather in Sydney.

Lithium - Pharmacological and Toxicological Aspects: The Current State of the Art

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Lithium is the smallest monovalent cation with many different biological effects. Although lithium is present in the pharmacotherapy of psychiatric illnesses for decades, its precise mechanism of action is still not clarified. Today lithium represents first-line therapy for bipolar disorders (because it possesses both antimanic and antidepressant properties) and the adjunctive treatment for major depression (due to its antisuicidal effects). Beside, lithium showed some protective effects in neurological diseases including acute neural injury, chronic degenerative conditions, Alzheimer's disease as well as in treating leucopenia, hepatitis and some renal diseases. Recent evidence suggested that lithium also possesses some anticancer properties due to its inhibition of Glycogen Synthase Kinase 3 beta (GSK3β) which is included in the regulation of a lot of important cellular processes such as: glycogen metabolism, inflammation, immunomodulation, apoptosis, tissue injury, regeneration etc.

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Although recent evidence suggested a potential utility of lithium in different conditions, its broader use in clinical practice still trails. The reason for this is a narrow therapeutic index of lithium, numerous toxic effects in various organ systems and some clinically relevant interactions with other drugs. Additionally, it is necessary to perform more preclinical as well as clinical studies in order to a precise therapeutic range of lithium, as well as its detailed mechanism of action. The aim of this review is to summarize the current knowledge concerning the pharmacological and toxicological effects of lithium.

Asymmetrical reliability of the Alda score favours a dichotomous representation of lithium responsiveness

The Alda score is commonly used to quantify lithium responsiveness in bipolar disorder. Most often, this score is dichotomized into “responder” and “non-responder” categories, respectively. This practice is often criticized as inappropriate, since continuous variables are thought to invariably be “more informative” than their dichotomizations. We therefore investigated the degree of informativeness across raw and dichotomized versions of the Alda score, using data from a published study of the scale’s inter-rater reliability (n = 59 raters of 12 standardized vignettes each). After learning a generative model for the relationship between observed and ground truth scores (the latter defined by a consensus rating of the 12 vignettes), we show that the dichotomized scale is more robust to inter-rater disagreement than the raw 0-10 scale. Further theoretical analysis shows that when a measure’s reliability is stronger at one extreme of the continuum—a scenario which has received little-to-no statistical attention, but which likely occurs for the Alda score ≥ 7—dichotomization of a continuous variable may be more informative concerning its ground truth value, particularly in the presence of noise. Our study suggests that research employing the Alda score of lithium responsiveness should continue using the dichotomous definition, particularly when data are sampled across multiple raters.

Delineating and validating higher-order dimensions of psychopathology in the Adolescent Brain Cognitive Development (ABCD) study

Hierarchical dimensional systems of psychopathology promise more informative descriptions for understanding risk and predicting outcome than traditional diagnostic systems, but it is unclear how many major dimensions they should include. We delineated the hierarchy of childhood and adult psychopathology and validated it against clinically relevant measures. Participants were 9987 9- and 10-year-old children and their parents from the Adolescent Brain Cognitive Development (ABCD) study. Factor analyses of items from the Child Behavior Checklist and Adult Self-Report were run to delineate hierarchies of dimensions. We examined the familial aggregation of the psychopathology dimensions, and the ability of different factor solutions to account for risk factors, real-world functioning, cognitive functioning, and physical and mental health service utilization. A hierarchical structure with a general psychopathology ('p') factor at the apex and five specific factors (internalizing, somatoform, detachment, neurodevelopmental, and externalizing) emerged in children. Five similar dimensions emerged also in the parents. Child and parent p-factors correlated highly (r = 0.61, p < 0.001), and smaller but significant correlations emerged for convergent dimensions between parents and children after controlling for p-factors (r = 0.09-0.21, p < 0.001). A model with child p-factor alone explained mental health service utilization (R² = 0.23, p < 0.001), but up to five dimensions provided incremental validity to account for developmental risk and current functioning in children (R² = 0.03-0.19, p < 0.001). In this first investigation comprehensively mapping the psychopathology hierarchy in children and adults, we delineated a hierarchy of higher-order dimensions associated with a range of clinically relevant validators. These findings hold important implications for psychiatric nosology and future research in this sample.

Evidence for perturbed metabolic patterns in bipolar disorder subjects associated with lithium responsiveness

Bipolar disorder (BD) is multifactorial mood disorder characterized by alternating episodes of hyperactive mania and severe depression. Lithium is one of the most preferred drug used as mood stabilizer in treating BD. In this study, we examined the changes in plasma metabolome in BD subjects in the context of lithium responsiveness. Plasma samples from clinically defined, age and gender matched unrelated healthy controls and BD subjects (lithium responders and non-responders) were obtained and processed in positive and negative mode using untargeted liquid chromatography/mass spectrometry analysis. We identified significant alterations in plasma levels of dopamine along with its precursors (tyrosine and phenylalanine), branched chain amino acid such as valine and excitatory neurotransmitter glutamate between healthy control and BD subjects. Lipid molecules such as, eicosenoic acid and retinyl ester also showed distinguished patterns between control and BD individuals. Lithium responsiveness was markedly associated with significant differences in proline, L-gamma-glutamyl-isoleucine, dopamine, palmitic acid methyl ester, cholesterol sulfate, androsterone sulfate and 9S,12S,13S-triHOME levels. Altered metabolites enriched with key biochemical pathways associated with neuropsychiatry disorders. We hypothesize that BD pathogenesis and lithium responsiveness is associated with impaired homeostasis of amino acid and lipid metabolism.

Long-acting injectable antipsychotics as maintenance treatments for bipolar disorder-A critical review of the evidence

OBJECTIVES

The maintenance phase of bipolar disorder is arguably the most important. The aim of management during this time is to maintain wellness and prevent future episodes of illness. Medication is often the mainstay of treatment during this phase, but adherence to treatment is a significant problem. In recent years, long-acting injectable (LAI) solutions have been proposed, but these too have limitations. This paper discusses the options that are currently available and critically appraises the effectiveness of this strategy.

METHOD

The authors reviewed the small number of open-label and randomised studies on LAI medications in bipolar disorder and evaluated the efficacy and safety of these medications.

RESULTS

The studies reviewed show benefit of LAIs for the management of bipolar disorder but have several key limitations to the generalisability of findings to routine practice.

CONCLUSIONS

LAIs have an emerging role in the management of bipolar disorder and, although it is not without limitations, this strategy addresses some issues of long-term treatment and medication. Patients with bipolar disorder that are non-adherent or have an unstable illness with a predilection towards mania are possibly better suited to the use of LAIs, though more research is required to fully assess the effectiveness of this approach.

Lithium, valproate, and carbamazepine prescribing patterns for long-term treatment of bipolar I and II disorders: A prospective study

OBJECTIVE

This study aims to describe the prescription patterns of the mood stabilizers most commonly used for the treatment of bipolar I and II disorders (lithium, valproate, and carbamazepine) and to analyze the treatment outcomes.

METHODS

Two hundred and thirty-four outpatients with bipolar disorders receiving prophylactic treatment with lithium, valproate, carbamazepine, or their combination were followed up for at least 18 months in two Italian psychiatric centers specialized in mood disorders.

RESULTS

The combination of lithium and valproate or carbamazepine was the most common prophylactic treatment (54.3%), followed by valproate or carbamazepine (24%) and lithium monotherapy (22%). Polytherapy was prescribed mainly to patients with bipolar I disorder, a high number of previous episodes and lifetime psychotic symptoms, whereas valproate or carbamazepine monotherapy was prescribed to patients with anxiety comorbidity. The annual frequency of recurrences decreased significantly after entering the study in the overall sample, and the reduction was significantly higher in patients on lithium plus valproate or carbamazepine compared with the valproate or carbamazepine group, but not with the lithium monotherapy group. The number of mixed recurrences during the follow-up was significantly higher in patients on lithium plus valproate or carbamazepine.

CONCLUSIONS

Our findings may help clinicians to personalize long-term treatment to prevent relapses of bipolar disorder according to clinical presentation.

Modeling Complex Neurological Diseases with Stem Cells: A Study of Bipolar Disorder

The pathogenesis of bipolar disorder (BPD) is unknown. Using human-induced pluripotent stem cells (hiPSCs) to unravel pathological mechanisms in polygenic diseases is challenging, with few successful studies to date. However, hiPSCs from BPD patients responsive to lithium have offered unique opportunities to discern lithium's mechanism of action and hence gain insight into BPD pathology. By profiling the proteomics of BPD-hiPSC-derived neurons, we found that lithium alters the phosphorylation state of collapsin response mediator protein-2 (CRMP2). The "set point" for the ratio of pCRMP2:CRMP2 is elevated uniquely in hiPSC-derived neurons from lithium responsive (Li-R) BPD patients, but not other psychiatric and neurological disorders. Utilizing neurons differentiated from human patient stem cells as an in vitro platform, we were able to elucidate the mechanism driving the pathogenesis and pathophysiology of lithium-responsive BPD, heretofore unknown. Importantly, the findings in culture were validated in human postmortem material as well as in animal models of BPD behavior. These data suggest that the "lithium response pathway" in BPD governs CRMP2's phosphorylation, which regulates cytoskeletal organization, particularly in dendritic spines, leading to modulated neural networks that may underlie Li-R BPD pathogenesis. This chapter reviews the methodology of leveraging a functional agent, lithium, to identify unknown pathophysiological pathways with hiPSCs and how to translate this disease modeling approach to other neurological disorders.

Wnt Signaling in the Central Nervous System: New Insights in Health and Disease

Since its discovery, Wnt signaling has been shown to be one of the most crucial morphogens in development and during the maturation of central nervous system. Its action is relevant during the establishment and maintenance of synaptic structure and neuronal function. In this chapter, we will discuss the most recent evidence on these aspects, and we will explore the evidence that involves Wnt signaling on other less known functions, such as in adult neurogenesis, in the generation of oscillatory neural rhythms, and in adult behavior. The dysfunction of Wnt signaling at different levels will be also discussed, in particular in those aspects that have been found to be linked with several neurodegenerative diseases and neurological disorders. Finally, we will address the possibility of Wnt signaling manipulation to treat those pathophysiological aspects.

Cognitive function, treatment response to lithium, and social functioning in Japanese patients with bipolar disorder

OBJECTIVES

Patients with bipolar disorder often suffer from cognitive impairment that significantly influences their functional outcome. However, it remains unknown whether lithium has a central role in cognition and functional outcome. We examined whether cognition and functional outcome were predicted by demographic and clinical variables, including the response to lithium, in lithium-treated patients with bipolar disorder.

METHODS

We evaluated 96 lithium-treated euthymic patients with bipolar disorder and 196 age- and-gender-matched healthy controls, using the Brief Assessment of Cognition in Schizophrenia (BACS). The patients were also assessed using the Social Functioning Scale (SFS) and "The Retrospective Criteria of Long-Term Treatment Response in Research Subjects with Bipolar Disorder" (Alda) scale, which was evaluated as either a continuous measure of the total scale or a dichotomous criterion.

RESULTS

Multiple regression analysis revealed two key findings: first, that the premorbid intelligence quotient, age, and number of mood episodes were predictors of the BACS composite score; and, second, that the BACS composite score, negative symptoms, and continuous measure on the total Alda scale (but not its dichotomy) predicted the total SFS score. Structural equation modeling (SEM) was used to confirm these findings, and additionally revealed that the Alda scale was significantly associated with negative symptoms and also the number of mood episodes, regardless of how it was evaluated.

CONCLUSIONS

SEM delineated how demographic and clinical variables, cognitive performance, and response to lithium treatment were causally associated with, and converged on, social function. The putative role of the Alda scale for social function warrants further study.

Lithium: A classic drug-Frequently discussed, but, sadly, seldom prescribed!

OBJECTIVE

Distinguished authors in the field have repeatedly alerted psychiatrists of the alarming trends in the treatment of bipolar disorders: decline of lithium use, paralleled by the increase of prescribing anticonvulsants and second-generation antipsychotic drugs. Research has been conducted in order to explore the factors that led to this development and to provide arguments for the need to reverse this trend.

METHOD

This paper represents a narrative review of the literature containing retrieved research articles focusing on the efficacy of lithium. The papers included in this overview were published prior to June 2016; additional papers were identified by searching the reference lists of reviewed articles. Taking into account the amount of literature available, no search can be exhaustive; on the other hand, the studies consulted, all of which explore the effectiveness of various compounds, may have their own limitations as well.

RESULTS

The evidence of the effectiveness of lithium in the treatment of acute mania, acute bipolar depression and the prevention of manic and depressive episodes is compelling. Lithium is the most effective augmentation agent in treatment-resistant depression. Its anti-suicidal effects are well established. The neuroprotective effects of lithium have been demonstrated in case-control studies and in population-based research. It has been established that starting lithium early in the course of the disorder reduces the rates of treatment non-response.

CONCLUSIONS

Despite abundant evidence regarding the efficacy of lithium and its effectiveness in the treatment of bipolar disorders, its use is declining at the beginning of the 21st century. It is of paramount importance to keep reminding psychiatrists and educating physicians about the unique properties of lithium and about monitoring patients treated with lithium, since it has been suggested that lithium should once again become the first-line treatment for bipolar disorders.

The use of lithium for the treatment of bipolar disorder: Recommendations from clinical practice guidelines

BACKGROUND

Lithium is an effective mood stabilizer that is used principally for the management of bipolar disorder (BD). Its administration is complex and often requires sophisticated management and assiduous monitoring. When considering the use of lithium therapy for bipolar disorder, clinicians are advised to refer to recommendations outlined in clinical practice guidelines (CPGs); but because of varying emphases placed by different international CPGs, recommendations addressing the practical use of lithium lack consistency.

METHOD

In order to inform clinicians of optimal lithium therapy for bipolar disorder, we compared and synthesized recommendations for the treatment of bipolar disorder made by recognized CPGs internationally. We conducted a search of the literature and extracted guidance across multiple clinical issues, including clinical indications, disorder subtypes, additional uses, special populations, practical aspects, and side effects.

RESULTS

Collectively, CPGs consider lithium most robustly as a first-line intervention for maintenance treatment of bipolar disorder and strongly for the treatment of mania, with relatively modest support for the management of acute bipolar depression. Additionally, there is consensus across the CPGs that lithium tangibly reduces the risk of suicide. Generally, CPGs provide guidance on the many facets of initiating and maintaining patients on lithium therapy, but individually the CPGs varied in terms of depth and practical guidance they provide across these areas. However, consensus was established across many key areas of practice such as the ideal lithium plasma concentration for maintenance and monitoring (0.6-0.8mmol/L), along with the need for regular monitoring of renal and endocrine function. However, with more complex aspects (e.g., atypical presentations) and in special populations (e.g., youth; pregnancy and post-partum; older adults), guidance varied considerably and clear consensus recommendations were more difficult to achieve. In younger adults desirable plasma lithium levels of 0.6-0.8mmol/L can perhaps be achieved with comparatively lower doses and in the very elderly it may be prudent to target lower plasma levels in the first instance. These are important practical points for consideration that, along with many others offered throughout the article, should assist clinicians in dissecting the more complex aspects of management with greater precision.

LIMITATIONS

This review was limited to CPGs written in English. CPGs are themselves limited by reliance on evidence that often has little resemblance to real-world presentations. An important area that is not sufficiently addressed in the CPGs is clear guidance on the cessation of lithium therapy.

CONCLUSIONS

Further research is needed on many aspects of lithium therapy and this alongside existing knowledge needs to be used more consistently to inform CPGs, which should also incorporate empirical evidence and clinical experience. The recommendations in this paper provide a useful synthesis of guidance available currently.

Pharmacogenomic aspects of bipolar disorder: An update

The hopes for readily implementable precision medicine are high. For many complex disorders, such as bipolar disorder, these hopes critically hinge on tangible successes in pharmacogenetics of treatment response or susceptibility to adverse events. In this article, we review the current state of pharmacogenomics of bipolar disorder including latest results from candidate genes and genome-wide association studies. The majority of studies focus on response to lithium treatment. Although a host of genes has been studied, hardly any replicated findings have emerged so far. Very small samples sizes and heterogeneous phenotype definition may be considered the major impediments to success in this field. Drawing from current experiences and successes in studies on diagnostic psychiatric phenotypes, we suggest several approaches for our way forward.

Probing the lithium-response pathway in hiPSCs implicates the phosphoregulatory set-point for a cytoskeletal modulator in bipolar pathogenesis

The molecular pathogenesis of bipolar disorder (BPD) is poorly understood. Using human-induced pluripotent stem cells (hiPSCs) to unravel such mechanisms in polygenic diseases is generally challenging. However, hiPSCs from BPD patients responsive to lithium offered unique opportunities to discern lithium's target and hence gain molecular insight into BPD. By profiling the proteomics of BDP-hiPSC-derived neurons, we found that lithium alters the phosphorylation state of collapsin response mediator protein-2 (CRMP2). Active nonphosphorylated CRMP2, which binds cytoskeleton, is present throughout the neuron; inactive phosphorylated CRMP2, which dissociates from cytoskeleton, exits dendritic spines. CRMP2 elimination yields aberrant dendritogenesis with diminished spine density and lost lithium responsiveness (LiR). The "set-point" for the ratio of pCRMP2:CRMP2 is elevated uniquely in hiPSC-derived neurons from LiR BPD patients, but not with other psychiatric (including lithium-nonresponsive BPD) and neurological disorders. Lithium (and other pathway modulators) lowers pCRMP2, increasing spine area and density. Human BPD brains show similarly elevated ratios and diminished spine densities; lithium therapy normalizes the ratios and spines. Consistent with such "spine-opathies," human LiR BPD neurons with abnormal ratios evince abnormally steep slopes for calcium flux; lithium normalizes both. Behaviorally, transgenic mice that reproduce lithium's postulated site-of-action in dephosphorylating CRMP2 emulate LiR in BPD. These data suggest that the "lithium response pathway" in BPD governs CRMP2's phosphorylation, which regulates cytoskeletal organization, particularly in spines, modulating neural networks. Aberrations in the posttranslational regulation of this developmentally critical molecule may underlie LiR BPD pathogenesis. Instructively, examining the proteomic profile in hiPSCs of a functional agent-even one whose mechanism-of-action is unknown-might reveal otherwise inscrutable intracellular pathogenic pathways.

In situ cellular level Raman spectroscopy of the thyroid

We report a novel Raman spectroscopy method for in situ cellular level analysis of the thyroid. Thyroids are harvested from control and lithium treated mice. Lithium is used to treat bipolar disorder, but affects thyroid function. Raman spectra are acquired with a confocal setup (514 nm laser, 20 µm spot) focused on a follicular lumen. Raman peaks are observed at 1440, 1656, and 1746 cm^-1, corresponding to tyrosine, an important amino acid for protein synthesis. Peaks are also observed at 563, 1087, 1265 and 1301 cm^-1. With lithium, the tyrosine peaks increase, indicating tyrosine buildup. Raman spectroscopy can study the impact of many exogenous treatments on thyroid biochemistry.

Does the "Silver Bullet" Lose its Shine Over the Time? Assessment of Loss of Lithium Response in a Preliminary Sample of Bipolar Disorder Outpatients

Background:

Though often perceived as a “silver bullet” treatment for bipolar disorder (BD), lithium has seldom reported to lose its efficacy over the time.

Objective:

The aim of the present study was to assess cases of refractoriness toward restarted lithium in BD patients who failed to preserve maintenance.

Method:

Treatment trajectories associated with re-instituted lithium following loss of achieved lithium-based maintenance in BD were retrospectively reviewed for 37 BD-I patients (median age 52 years; F:M=17:20 or 46% of the total) over an 8.1-month period on average.

Results:

In our sample only 4 cases (roughly 11% of the total, of whom F:M=2:2) developed refractoriness towards lithium after its discontinuation. Thirty-three controls (F:M=15:18) maintained lithium response at the time of re-institution. No statistically significant difference between cases and controls was observed with respect to a number of demographic and clinical features but for time spent before first trial ever with lithium in life (8.5 vs. 3 years; U=24.5, Z=-2.048, p=.041) and length of lithium discontinuation until new therapeutic attempt (5.5 vs. 2 years; U=8, Z=-2.927, p=.003) between cases vs. controls respectively. Tapering off of lithium was significantly faster among cases vs. controls (1 vs. 7 days; U=22, Z=-2.187), though both subgroups had worrisome high rates of poor adherence overall.

Conclusion:

Although intrinsic limitations of the present preliminary assessment hamper the validity and generalizability of overall results, stating the clinical relevance of the topic further prospective research is warranted. The eventual occurrence of lithium refractoriness may indeed be associated with peculiar course trajectories and therapeutic outcomes ultimately urging the prescribing clinicians to put efforts in preserving maintenance of BD in the absence of any conclusive research insight on the matter.

Lithiumeter: Version 2.0

BACKGROUND

The Lithiumeter was developed as a visual and practical guide for determining lithium levels in the management of bipolar disorder (BD). It appears to have been well received, as evidenced by its increasing popularity amongst doctors as a deskside clinical aide, and adoption and reproduction of the schematic in clinical guidelines and texts. However, since its publication 5 years ago, key basic neuroscience and clinical research developments pertaining to lithium have significantly advanced our understanding, necessitating further refinement of guidance concerning the practicalities of lithium therapy.

METHODS

Literature concerning the indications for, and therapeutic levels of, lithium and the associated acute and chronic risks of therapy was scrutinized as part of updating clinical practice guidelines. We have reviewed these updates and identified significant areas of change with respect to the previous Lithiumeter (version 1.0).

RESULTS

Since 2011, updated clinical practice guidelines have narrowed the indicated plasma lithium concentration for maintenance therapy, suggesting that additional guidance is necessary for optimizing treatment. Relevant updated clinical guidance was integrated to constitute the Lithiumeter 2.0, which provides a more comprehensive overview of the practical aspects of lithium therapy while maintaining a focus on optimization of lithium levels, such as differential titration of lithium depending on the current mood state.

CONCLUSIONS

The Lithiumeter 2.0 is an update that clinicians will find useful for their practice. By addressing some of the issues faced in clinical practice, translational clinical research will continue to inform the Lithiumeter in future updates.

Chronic lithium treatment rectifies maladaptive dopamine release in the nucleus accumbens

Chronic lithium treatment effectively reduces behavioral phenotypes of mania in humans and rodents. The mechanisms by which lithium exerts these actions are poorly understood. Pre-clinical and clinical evidence have implicated increased mesolimbic dopamine (DA) neurotransmission with mania. We used fast-scan cyclic voltammetry to characterize changes in extracellular DA concentrations in the nucleus accumbens (NAc) core evoked by 20 and 60 Hz electrical stimulation of the ventral tegmental area (VTA) in C57BL6/J mice treated either acutely or chronically with lithium. The effects of chronic lithium treatment on the availability of DA for release were assessed by depleting readily releasable DA using short inter-train intervals, or administering d-amphetamine acutely to mobilize readily releasable DA. Chronic, but not acute, lithium treatment decreased the amplitude of DA responses in the NAc following 60 Hz pulse train stimulation. Neither lithium treatment altered the kinetics of DA release or reuptake. Chronic treatment did not impact the progressive reduction in the amplitude of DA responses when, using 20 or 60 Hz pulse trains, the VTA was stimulated every 6 s to deplete DA. Specifically, the amplitude of DA responses to 60 Hz pulse trains was initially reduced compared to control mice, but by the fifth pulse train, there was no longer a treatment effect. However, chronic lithium treatment attenuated d-amphetamine-induced increases in DA responses to 20 Hz pulse trains stimulation. Our data suggest that long-term administration of lithium may ameliorate mania phenotypes by normalizing the readily releasable DA pool in VTA axon terminals in the NAc. Read the Editorial Highlight for this article on Page 520.

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

Lithium is the most effective and well established treatment for bipolar disorder, and it has a broad array of effects within cellular pathways. However, the specific processes through which therapeutic effects occur and are maintained in bipolar disorder remain unclear. This paper provides a timely update to an authoritative review of pertinent findings that was published in CNS Drugs in 2013. A literature search was conducted using the Scopus database, and was limited by year (from 2012). There has been a resurgence of interest in lithium therapy mechanisms, perhaps driven by technical advancements in recent years that permit the examination of cellular mechanisms underpinning the effects of lithium-along with the reuptake of lithium in clinical practice. Recent research has further cemented glycogen synthase kinase 3β (GSK3β) inhibition as a key mechanism, and the inter-associations between GSK3β-mediated neuroprotective, anti-oxidative and neurotransmission mechanisms have been further elucidated. In addition to highly illustrative cellular research, studies examining higher-order biological systems, such as circadian rhythms, as well as employing innovative animal and human models, have increased our understanding of how lithium-induced changes at the cellular level possibly translate to changes at behavioural and clinical levels. Neural circuitry research is yet to identify clear mechanisms of change in bipolar disorder in response to treatment with lithium, but important structural findings have demonstrated links to the modulation of cellular mechanisms, and peripheral marker and pharmacogenetic studies are showing promising findings that will likely inform the exploration for predictors of lithium treatment response. With a deeper understanding of lithium's therapeutic mechanisms-from the cellular to clinical levels of investigation-comes the opportunity to develop predictive models of lithium treatment response and identify novel drug targets, and recent findings have provided important leads towards these goals.

The Lithium Battery: assessing the neurocognitive profile of lithium in bipolar disorder

OBJECTIVE

The aim of the present study was to characterize the neurocognitive effects of lithium in bipolar disorder to inform clinical and research approaches for further investigation.

METHODS

Key words pertaining to neurocognition in bipolar disorder and lithium treatment were used to search recognized databases to identify relevant literature. The authors also retrieved gray literature (e.g., book chapters) known to them and examined pertinent articles from bibliographies.

RESULTS

A limited number of studies have examined the effects of lithium on neurocognition in bipolar disorder and, although in some domains a consistent picture emerges, in many domains the findings are mixed. Lithium administration appears to reshape key components of neurocognition - in particular, psychomotor speed, verbal memory, and verbal fluency. Notably, it has a sophisticated neurocognitive profile, such that while lithium impairs neurocognition across some domains, it seemingly preserves others - possibly those vulnerable to the effects of bipolar disorder. Furthermore, its effects are likely to be direct and indirect (via mood, for example) and cumulative with duration of treatment. Disentangling the components of neurocognition modulated by lithium in the context of a fluctuating and complex illness such as bipolar disorder is a significant challenge but one that therefore demands a stratified and systematic approach, such as that provided by the Lithium Battery.

CONCLUSIONS

In order to delineate the effects of lithium therapy on neurocognition in bipolar disorder within both research and clinical practice, a greater understanding and measurement of the relatively stable neurocognitive components is needed to examine those that indeed change with lithium treatment. In order to achieve this, we propose a Lithium Battery-Clinical and a Lithium Battery-Research that can be applied to these respective settings.

Royal Australian and New Zealand College of Psychiatrists clinical practice guidelines for mood disorders

OBJECTIVES

To provide guidance for the management of mood disorders, based on scientific evidence supplemented by expert clinical consensus and formulate recommendations to maximise clinical salience and utility.

METHODS

Articles and information sourced from search engines including PubMed and EMBASE, MEDLINE, PsycINFO and Google Scholar were supplemented by literature known to the mood disorders committee (MDC) (e.g., books, book chapters and government reports) and from published depression and bipolar disorder guidelines. Information was reviewed and discussed by members of the MDC and findings were then formulated into consensus-based recommendations and clinical guidance. The guidelines were subjected to rigorous successive consultation and external review involving: expert and clinical advisors, the public, key stakeholders, professional bodies and specialist groups with interest in mood disorders.

RESULTS

The Royal Australian and New Zealand College of Psychiatrists clinical practice guidelines for mood disorders (Mood Disorders CPG) provide up-to-date guidance and advice regarding the management of mood disorders that is informed by evidence and clinical experience. The Mood Disorders CPG is intended for clinical use by psychiatrists, psychologists, physicians and others with an interest in mental health care.

CONCLUSIONS

The Mood Disorder CPG is the first Clinical Practice Guideline to address both depressive and bipolar disorders. It provides up-to-date recommendations and guidance within an evidence-based framework, supplemented by expert clinical consensus.

MOOD DISORDERS COMMITTEE

Professor Gin Malhi (Chair), Professor Darryl Bassett, Professor Philip Boyce, Professor Richard Bryant, Professor Paul Fitzgerald, Dr Kristina Fritz, Professor Malcolm Hopwood, Dr Bill Lyndon, Professor Roger Mulder, Professor Greg Murray, Professor Richard Porter and Associate Professor Ajeet Singh.

INTERNATIONAL EXPERT ADVISORS

Professor Carlo Altamura, Dr Francesco Colom, Professor Mark George, Professor Guy Goodwin, Professor Roger McIntyre, Dr Roger Ng, Professor John O'Brien, Professor Harold Sackeim, Professor Jan Scott, Dr Nobuhiro Sugiyama, Professor Eduard Vieta, Professor Lakshmi Yatham.

AUSTRALIAN AND NEW ZEALAND EXPERT ADVISORS

Professor Marie-Paule Austin, Professor Michael Berk, Dr Yulisha Byrow, Professor Helen Christensen, Dr Nick De Felice, A/Professor Seetal Dodd, A/Professor Megan Galbally, Dr Josh Geffen, Professor Philip Hazell, A/Professor David Horgan, A/Professor Felice Jacka, Professor Gordon Johnson, Professor Anthony Jorm, Dr Jon-Paul Khoo, Professor Jayashri Kulkarni, Dr Cameron Lacey, Dr Noeline Latt, Professor Florence Levy, A/Professor Andrew Lewis, Professor Colleen Loo, Dr Thomas Mayze, Dr Linton Meagher, Professor Philip Mitchell, Professor Daniel O'Connor, Dr Nick O'Connor, Dr Tim Outhred, Dr Mark Rowe, Dr Narelle Shadbolt, Dr Martien Snellen, Professor John Tiller, Dr Bill Watkins, Dr Raymond Wu.

Lithium nephrotoxicity

Reports of toxic effects on the kidney of lithium treatment emerged very soon after lithium therapy was introduced. Lithium-induced nephrogenic diabetes insipidus is usually self-limiting or not clinically dangerous. Some reports of irreversible chronic kidney disease and renal failure were difficult to attribute to lithium treatment since chronic kidney disease and renal failure exist in the population at large. In recent years, large-scale epidemiological studies have convincingly shown that lithium treatment elevates the risk of chronic kidney disease and renal failure. Most patients do not experience renal side effects. The most common side effect of polyuria only weakly predicts increasing creatinine or reduced kidney function. Among those patients who do experience decrease in creatinine clearance, some may require continuation of lithium treatment even as their creatinine increases. Other patients may be able to switch to a different mood stabilizer medication, but kidney function may continue to deteriorate even after lithium cessation. Most, but not all, evidence today recommends using a lower lithium plasma level target for long-term maintenance and thereby reducing risks of severe nephrotoxicity.

Inflammation and lithium: clues to mechanisms contributing to suicide-linked traits

Suicide is one of the leading causes of death in the United States, yet it remains difficult to understand the mechanistic provocations and to intervene therapeutically. Stress is recognized as a frequent precursor to suicide. Psychological stress is well established to cause activation of the inflammatory response, including causing neuroinflammation, an increase of inflammatory molecules in the central nervous system (CNS). Neuroinflammation is increasingly recognized as affecting many aspects of CNS functions and behaviors. In particular, much evidence demonstrates that inflammatory markers are elevated in traits that have been linked to suicidal behavior, including aggression, impulsivity and depression. Lithium is recognized as significantly reducing suicidal behavior, is anti-inflammatory and diminishes aggression, impulsivity and depression traits, each of which is associated with elevated inflammation. The anti-inflammatory effects of lithium result from its inhibition of glycogen synthase kinase-3 (GSK3). GSK3 has been demonstrated to strongly promote inflammation, aggressive behavior in rodents and depression-like behaviors in rodents, whereas regulation of impulsivity by GSK3 has not yet been investigated. Altogether, evidence is building supporting the hypothesis that stress activates GSK3, which in turn promotes inflammation, and that inflammation is linked to behaviors associated with suicide, including particularly aggression, impulsivity and depression. Further investigation of these links may provide a clearer understanding of the causes of suicidal behavior and provide leads for the development of effective preventative interventions, which may include inhibitors of GSK3.

Histone deacetylase inhibitors reverse manic-like behaviors and protect the rat brain from energetic metabolic alterations induced by ouabain

Studies have revealed alterations in mitochondrial complexes in the brains of bipolar patients. However, few studies have examined changes in the enzymes of the tricarboxylic acid cycle. Several preclinical studies have suggested that histone deacetylase inhibitors may have antimanic effects. The present study aims to investigate the effects of lithium, valproate and sodium butyrate, a histone deacetylase inhibitor, on the activity of tricarboxylic acid cycle enzymes in the brains of rats subjected to an animal model of mania induced by ouabain. Wistar rats received a single intracerebroventricular injection of ouabain or cerebrospinal fluid. Starting on the day following the intracerebroventricular injection, the rats were treated for 7days with intraperitoneal injections of saline, lithium, valproate or sodium butyrate. Risk-taking behavior, locomotor and exploratory activities were measured using the open-field test. Citrate synthase, succinate dehydrogenase, and malate dehydrogenase were examined in the frontal cortex and hippocampus. All treatments reversed ouabain-related risk-taking behavior and hyperactivity in the open-field test. Ouabain inhibited tricarboxylic acid cycle enzymes in the brain, and valproate and sodium butyrate but not lithium reversed this ouabain-induced dysfunction. Thus, protecting the tricarboxylic acid cycle may contribute to the therapeutic effects of histone deacetylase inhibitors.

Effects of lithium on inflammation

Lithium is an effective medication for the treatment of bipolar affective disorder. Accumulating evidence suggests that inflammation plays a role in the pathogenesis of bipolar disorder and that lithium has anti-inflammatory effects that may contribute to its therapeutic efficacy. This article summarizes the studies which examined the effects of lithium on pro- and anti-inflammatory mediators. Some of the summarized data suggest that lithium exerts anti-inflammatory effects (e.g., suppression of cyclooxygenase-2 expression, inhibition of interleukin (IL)-1β and tumor necrosis factor-α production, and enhancement of IL-2 and IL-10 synthesis). Nevertheless, there is a large body of data which indicates that under certain experimental conditions lithium also exhibits pro-inflammatory properties (e.g., induction of IL-4, IL-6 and other pro-inflammatory cytokines synthesis). The reviewed studies utilized various experimental model systems, and it is thus difficult to draw an unequivocal conclusion regarding the effect of lithium on specific inflammatory mediators.

Effect of quetiapine XR on depressive symptoms and sleep quality compared with lithium in patients with bipolar depression

BACKGROUND

Bipolar depression is one of the most serious psychiatric conditions. In addition, sleep disturbance in bipolar disorder is common, and therapeutic agents restoring sleep disturbances in bipolar disorder patients will be clinically beneficial. In the current study, we compared the effect of quetiapine XR with lithium on depressive symptoms and sleep in bipolar depression patients during 8 weeks of trial.

METHODS

An open-label, randomized comparison of sleep-activity and depressive symptoms between 8-week quetiapine XR monotherapy and lithium monotherapy for bipolar depression was conducted. Each assessment consisted of HDRS-17, Clinical Global Impression-severity (CGI-S), and self-reported Pittsburgh Sleep Quality Index (PSQI). Actigraphy-measured sleep parameters were assessed.

RESULTS

A total of 42 patients (35.7±10.9 years; gender: male 15, female 27) with bipolar depression were screened out. Out of 42 patients, six patients were excluded before randomization. After randomization, seven patients were withdrawn. Twenty-nine patients with more than two visits after randomization (lithium group: 17, quetiapine XR group: 12, mean age: 36.1±10.4, gender: male 13, female 16) were included in the final analysis. In both groups, Hamilton Depression Rating Scale (HDRS) scores were significantly decreased at weeks 1, 2, 4, 6, and 8 compared with baseline. Remission rate (HDRS≤7) in the quetiapine XR was significantly higher than that of the lithium group. In the quetiapine XR group, PSQI scores at weeks 1, 2, 4, 6, and 8 was significantly decreased compared with baseline. Sleep efficiency at weeks 6 and 8 was significantly increased. WASO at week 8 was significantly decreased.

LIMITATIONS

First, the present study was conducted with the relatively small number of study subjects. Second, bias could have affected the study results due to its open-label design. Third, study subjects were made up of high proportion of bipolar II disorder patients.

CONCLUSIONS

Quetiapine XR monotherapy was more effective in treating bipolar depression than lithium. In particular, quetiapine XR treatment improved both subjective and objective sleep quality in patients with bipolar depression. However, relationship between favorable sleep quality and depressive symptom improvement were limited.

Molecular actions and clinical pharmacogenetics of lithium therapy

Mood disorders, including bipolar disorder and depression, are relatively common human diseases for which pharmacological treatment options are often not optimal. Among existing pharmacological agents and mood stabilizers used for the treatment of mood disorders, lithium has a unique clinical profile. Lithium has efficacy in the treatment of bipolar disorder generally, and in particular mania, while also being useful in the adjunct treatment of refractory depression. In addition to antimanic and adjunct antidepressant efficacy, lithium is also proven effective in the reduction of suicide and suicidal behaviors. However, only a subset of patients manifests beneficial responses to lithium therapy and the underlying genetic factors of response are not exactly known. Here we discuss preclinical research suggesting mechanisms likely to underlie lithium's therapeutic actions including direct targets inositol monophosphatase and glycogen synthase kinase-3 (GSK-3) among others, as well as indirect actions including modulation of neurotrophic and neurotransmitter systems and circadian function. We follow with a discussion of current knowledge related to the pharmacogenetic underpinnings of effective lithium therapy in patients within this context. Progress in elucidation of genetic factors that may be involved in human response to lithium pharmacology has been slow, and there is still limited conclusive evidence for the role of a particular genetic factor. However, the development of new approaches such as genome-wide association studies (GWAS), and increased use of genetic testing and improved identification of mood disorder patients sub-groups will lead to improved elucidation of relevant genetic factors in the future.

Stability of lithium treatment in bipolar disorder - long-term follow-up of 346 patients

Background

The purpose of this study was to investigate the effectiveness and stability of long-term lithium treatment in a prospective, international, multicenter cohort of bipolar patients in a naturalistic setting.

Methods

Patients were selected according to DSM IV criteria for bipolar disorder and required long-term treatment. They were prospectively followed and documented in five centers belonging to the International Group for the Study of Lithium-Treated Patients. This was a prospective cohort study without a comparison group. Lithium treatment was administered in a naturalistic and specialized outpatient setting. All patients underwent a comprehensive psychiatric examination, which included the use of standard rating scales, as well as an evaluation of clinical course based on the morbidity index (MI).

Wald tests were used to assess the significance of fixed effects and covariates when analyzing the relationship between depressive, manic, and total morbidity index and several characteristics of illness course.

Results and discussion

A total of 346 patients with bipolar disorder I or II were followed for a mean period of 10.0 years (standard deviation (SD) 6.2, range 1 to 20). The morbidity index remained stable over time: the mean MI was 0.125 (SD 0.299) in year 1 and 0.110 (SD 0.267) in year 20. The MI was not associated with the duration of lithium treatment, the number or frequency of episodes prior to treatment, or latency from the onset of bipolar disorder to the start of lithium treatment. The drop-out rate was high over the study period. Our findings suggest that long-term response to lithium maintenance treatment remains stable over time.

The ARIQUELI study: potentiation of quetiapine in bipolar I nonresponders with lithium versus aripiprazole

BACKGROUND

The treatment of bipolar disorder (BD) remains a challenge due to the complexity of the disease. Current guidelines represent an effort to assist clinicians in routine practice but have several limitations, particularly concerning long-term treatment. The ARIQUELI (efficacy and tolerability of the combination of lithium or aripiprazole in young bipolar non or partial responders to quetiapine monotherapy) study aims to evaluate two different augmentation strategies for quetiapine nonresponders or partial responders in acute and maintenance phases of BD treatment.

METHODS/DESIGN

The ARIQUELI study is a single-site, parallel-group, randomized, outcome assessor-blinded trial. BD I patients according to the DSM-IV-TR, in depressive, manic/hypomanic or mixed episode, aged 18 to 40 years, are eligible. After diagnostic assessments, patients initiated treatment in phase I with quetiapine. Nonresponders or partial responders after 8 weeks are allocated into one of two groups, potentiated with either lithium (0.5 to 0.8 mEq/l) or aripiprazole (10 or 15 mg). Patients will be followed up for 8 weeks in phase I (acute treatment), 6 months in phase II (continuation treatment) and 12 months in phase III (maintenance treatment). Outcome assessors are blinded to the treatment. The primary outcome is the evaluation of changes in mean scores on the CGI-BP-M between baseline and the endpoint at the end of each study phase.

DISCUSSION

The ARIQUELI study is currently in progress, with patients undergoing acute treatment (phase I), potentiation (phase II) and maintenance (phase III). The study will be extended until January 2015. Trials comparing lithium and aripiprazole with potentiate treatment in young BD I nonresponders to quetiapine in monotherapy can provide relevant information on the safety of these drugs in clinical practice. Long-term treatment is an issue of great importance and should be evaluated further through more in-depth studies given that BD is a chronic disease.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01710163.

Mood-dependent changes of serum lithium concentration in a rapid cycling patient maintained on stable doses of lithium carbonate

OBJECTIVE

Serum lithium levels may be influenced by mood state. We report on a 58-year-old female patient suffering from rapid cycling bipolar disorder. Her serum lithium levels varied greatly, despite stable medication.

METHODS

The patient was observed over a one-year period.

RESULTS

The patient received a stable medication of lithium carbonate (450 mg), valproate (1500 mg), and clozapine (200 mg). Investigating mood and serum lithium levels over one year revealed six manic and six depressive phases. The mean lithium serum level was 0.67 mmol/L in the depressive states, 0.39 mmol/L in the manic states (t = 4.11, p = 0.001 versus depression), and 0.40 mmol/L in the euthymic states (t = 3.58, p = 0.003 versus depression). Noncompliance was ruled out. The patient gained up to 8 kg during manic phases, accompanied by pretibial edema.

CONCLUSIONS

Changes in serum lithium concentration are probably not caused by altered lithium, but by water metabolism. During mania, body water increases, leading to dilution and therefore a reduction in serum lithium levels. As there is no proof for any other known cause of hypervolemia, we propose the hypothesis that the increase in body water is due to a variant of idiopathic edema.