Clinical and regulatory implications of active run-in phases in long-term studies for bipolar disorder

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.

Determinants of three-year clinical outcomes in real-world outpatients with bipolar disorder: The multicenter treatment survey for bipolar disorder in psychiatric outpatient clinics (MUSUBI)

BACKGROUND

There is limited evidence regarding predictors of long-term clinical outcomes in patients with bipolar disorder (BD). The objective of this study was to describe 3-year clinical outcomes and identify their predictors from participants in the multicenter treatment survey for BD in psychiatric outpatient clinics (MUSUBI).

METHODS

The MUSUBI was a naturalistic study investigating patients with BD in real-world clinical practice. Our study extracted data regarding 1647 outpatients with BD from 2016, 2017, and 2019 as baseline, 1-year, and 3-year assessments. As clinical outcomes, we assessed the presence of time ill (depressive and manic) during the 1 year prior to the 3-year assessment and durable remission (53 weeks or more) prior to the 3-year assessment.

RESULTS

Participants with durable remission prior to the 3-year assessment had significant associations with diagnosis of a personality disorder and duration of continuous remission at baseline. Regarding the presence of depressive symptoms during the 1 year prior to the 3-year assessment, work status, Global Assessment of Functioning (GAF) scores, suicidal ideation, and duration of continuous remission at baseline had significant associations with this outcome.

CONCLUSIONS

At the 3-year assessment, 19.3% of participants (318/1647) achieved durable remission, while 47.5% of them (782/1647) were not remitted. Our findings can help clinicians predict the illness course of BD by understanding demographic and clinical characteristics.

Pharmacological management of bipolar disorder: Japanese expert consensus

OBJECTIVES

The aim of this study was to develop a consensus guideline by certified experts of the Japanese Society of Clinical Neuropsychopharmacology on the psychopharmacological treatment for bipolar disorders I and II (BP-I and BP-II), in order to fill the gap in the literature and provide more concrete guidance for challenging and controversial real-world situations.

METHODS

Experts were asked to assess treatment options regarding 19 clinical situations of bipolar disorder with a nine-point Likert scale (one = "disagree" and nine = "agree"). According to the responses from 119 experts, the options were categorized into the first-, second-, and third-line treatments.

RESULTS

For the treatment of BP-I, lithium monotherapy was categorized as a first-line treatment for manic episodes (mean ± standard deviation score, 7.0 ± 2.2), depressive episodes (7.1 ± 2.0), and the maintenance phase (7.8 ± 1.8). Combination therapy of lithium and an atypical antipsychotic was endorsed for manic episodes (7.7 ± 1.7), depressive episodes with (7.1 ± 2.0) and without mixed features (6.9 ± 2.2), and the maintenance phase (6.9 ± 2.1). Similarly, in BP-II, lithium monotherapy was categorized as a first-line treatment for hypomanic episodes (7.3 ± 2.2), depressive episodes (7.0 ± 2.2), and the maintenance phase (7.3 ± 2.3), while combination therapy of lithium and an atypical antipsychotic was recommended for hypomanic episodes (6.9 ± 2.4).No antipsychotic monotherapy or antidepressant treatment was categorized as a first-line treatment for any type of episode.

CONCLUSIONS

These recommendations reflect the current evidence and represent the experts' consensus on using lithium for the treatment of bipolar disorder. Clinicians should consider the effectiveness and adverse effects of antipsychotic and antidepressant medications for the treatment of bipolar disorder.

Assessing risk of bias: a proposal for a unified framework for observational studies and randomized trials

BACKGROUND

Evidence based medicine aims to integrate scientific evidence, clinical experience, and patient values and preferences. Individual health care professionals need to appraise the evidence from randomized trials and observational studies when guidelines are not yet available. To date, tools for assessment of bias and terminologies for bias are specific for each study design. Moreover, most tools appeal only to methodological knowledge to detect bias, not to subject matter knowledge, i.e. in-depth medical knowledge about a topic. We propose a unified framework that enables the coherent assessment of bias across designs.

METHODS

Epidemiologists traditionally distinguish between three types of bias in observational studies: confounding, information bias, and selection bias. These biases result from a common cause, systematic error in the measurement or common effect of the intervention and outcome respectively. We applied this conceptual framework to randomized trials and show how it can be used to identify bias. The three sources of bias were illustrated with graphs that visually represent researchers' assumptions about the relationships between the investigated variables (causal diagrams).

RESULTS

Critical appraisal of evidence started with the definition of the research question in terms of the population of interest, the compared interventions and the main outcome. Next, we used causal diagrams to illustrate how each source of bias can lead to over- or underestimated treatment effects. Then, we discussed how randomization, blinded outcome measurement and intention-to-treat analysis minimize bias in trials. Finally, we identified study aspects that can only be appraised with subject matter knowledge, irrespective of study design.

CONCLUSIONS

The unified framework encompassed the three main sources of bias for the effect of an assigned intervention on an outcome. It facilitated the integration of methodological and subject matter knowledge in the assessment of bias. We hope that graphical diagrams will help clarify debate among professionals by reducing misunderstandings based on different terminology for bias.

Factors Associated with Non-Remission in Bipolar Disorder: The Multicenter Treatment Survey for Bipolar Disorder in Psychiatric Outpatient Clinics (MUSUBI)

PURPOSE

The aim of this study was to identify factors associated with non-remission in bipolar disorder.

PATIENTS AND METHODS

The multicenter treatment survey for bipolar disorder in psychiatric outpatient clinics (MUSUBI) study used a questionnaire administered at 176 clinics throughout Japan from September to October 2016. Clinic psychiatrists performed a retrospective medical record survey of consecutive cases with bipolar disorder. Patients were considered to be in remission if they met all of the following criteria: they were not in a mixed state, their manic or depressive symptoms were either borderline or nonexistent (corresponding to 2 or 1 points on the Clinical Global Impressions Scale, Bipolar Version), and their psychiatrists clinically considered them to be in remission. Enrolled patients were classified into remitters group and non-remitters group and demographic and clinical characteristics were contrasted between the groups. Non-remitters were compared with remitters, using a series of logistic regression analyses.

RESULTS

A total of 3130 patients (1420 men; mean age: 50.3 years) were included in this study; 1307 patients (41.8%) were in remission. Of the remaining 1823 patients, 1260 (40.3%) had mild to severe depression, 261 (8.3%) suffered from manic or hypomanic episodes, and 302 (9.6%) were in a mixed state. Logistic regression analyses found the following eight factors to be significantly correlated with non-remission in patients with bipolar disorder: female gender, younger age, unemployed status, rapid cycling pattern, comorbid alcohol/substance abuse, poorer social function, lithium non-use, and antidepressant use.

CONCLUSION

The MUSUBI study, the largest nationwide investigation on bipolar disorder, identified eight clinically relevant factors associated with non-remission in bipolar patients. They have important clinical implications; further prospective studies are necessary to replicate these findings and to guide better managements for those in serious needs.

Psychotropic Medication of Acute Episodes of Mood Disorders: Current Prescription Attitude in Two Psychiatric Wards in Cagliari, Italy

Background:

Medication of acute episodes of mood disorders has changed over the last decades following the results of randomized clinical trials.

Objective:

The aim of this study was to analyze medication prescribed at discharge from two psychiatric wards. We focused on hospitalization as one of the best opportunities to start prophylaxis.

Methods:

We examined retrospectively the clinical records of 357 patients hospitalized for mood episodes in two psychiatric wards in the Cagliari area (SPDC-1 and SPDC-2) between 1 January and 31 December 2016. We focused on the psychotropic medication prescribed at discharge from the hospital.

Results:

Most patients were discharged with antipsychotics (86%) and/or benzodiazepines (89%). Combined medication was frequent, including various co-administration of first-generation and/or second-generation antipsychotics (26% of patients), or antipsychotics combined with mood-stabilizers (51% of patients). There was a preferential prescription of first-generation antipsychotics in SPDC-1, and of second-generation antipsychotics in SPDC-2. Prescription of lithium was significantly more frequent in SPDC-1.

Conclusion:

Although the treatment was in line with randomized clinical trials, the choice of individual psychotropic agents differed significantly between the two wards. Different prescription attitudes can have consequences on the long-term outcome of patients discharged from the hospital after an acute mood episode.

Innovative approaches to bipolar disorder and its treatment

All psychiatric disorders have suffered from a dearth of truly novel pharmacological interventions. In bipolar disorder, lithium remains a mainstay of treatment, six decades since its effects were serendipitously discovered. The lack of progress reflects several factors, including ignorance of the disorder's pathophysiology and the complexities of the clinical phenotype. After reviewing the current status, we discuss some ways forward. First, we highlight the need for a richer characterization of the clinical profile, facilitated by novel devices and new forms of data capture and analysis; such data are already promoting a reevaluation of the phenotype, with an emphasis on mood instability rather than on discrete clinical episodes. Second, experimental medicine can provide early indications of target engagement and therapeutic response, reducing the time, cost, and risk involved in evaluating potential mood stabilizers. Third, genomic data can inform target identification and validation, such as the increasing evidence for involvement of calcium channel genes in bipolar disorder. Finally, new methods and models relevant to bipolar disorder, including stem cells and genetically modified mice, are being used to study key pathways and drug effects. A combination of these approaches has real potential to break the impasse and deliver genuinely new treatments.

Biological rationale and potential clinical use of gabapentin and pregabalin in bipolar disorder, insomnia and anxiety: protocol for a systematic review and meta-analysis

INTRODUCTION

Gabapentin has been extensively prescribed off-label for psychiatric indications, with little established evidence of efficacy. Gabapentin and pregabalin, a very similar drug with the same mechanism of action, bind to a subunit of voltage-dependent calcium channels which are implicated in the aetiopathogenesis of bipolar disorder, anxiety and insomnia. This systematic review and meta-analysis aims to collect and critically appraise all the available evidence about the efficacy and tolerability of gabapentin and pregabalin in the treatment of bipolar disorder, insomnia and anxiety.

METHODS AND ANALYSIS

We will include all randomised controlled trials (RCTs) reported as double-blind and comparing gabapentin or pregabalin with placebo or any other active pharmacological treatment (any preparation, dose, frequency, route of delivery or setting) in patients with bipolar disorder, anxiety or insomnia. For consideration of adverse effects (tolerability), single-blind or open-label RCTs and non-randomised evidence will also be summarised. The main outcomes will be efficacy (measured as dichotomous and continuous outcome) and acceptability (proportion of patients who dropped out of the allocated treatment). Published and unpublished studies will be sought through relevant database searches, trial registries and websites; all reference selection and data extraction will be conducted by at least 2 independent reviewers. We will conduct a random-effects meta-analysis to synthesise all evidence for each outcome. Heterogeneity between studies will be investigated by the I² statistic. Data from included studies will be entered into a funnel plot for investigation of small-study effects. No subgroup analysis will be undertaken, but we will carry out sensitivity analyses about combination treatment, psychiatric comorbidity, use of rescue medications and fixed versus random-effects model.

ETHICS AND DISSEMINATION

This review does not require ethical approval. This protocol has been registered on PROSPERO (CRD42016041802). The results of the systematic review will be disseminated via publication in a peer-reviewed journal.

Pharmacological agents to reduce readmissions in bipolar disorder

It is well recognized that medications have an important role to play in preventing relapse in bipolar disorder. The impact these treatments have on rates of admission to hospital in particular has been less well studied. We combined data on hospitalization from 11 randomized controlled trials in a network meta-analysis. We found that the published evidence demonstrates significant reductions in admission rates compared to placebo from lithium (risk ratio (RR) 0.44, 95% confidence interval (CI) 0.32-0.59), valproate (RR 0.50, 95% CI 0.28-0.90), a combination of lithium and valproate (RR 0.50, 95% CI 0.28-0.90), carbamazepine (RR 0.46, 95% CI 0.29-0.73) and olanzapine (RR 0.27, 95% CI 0.16-0.43). The evidence base contributing to these estimates remains fairly small, leading to broad confidence intervals for estimates of effect. More precise estimates could be obtained if unpublished outcomes data from other trials in this area became available. Several pharmacological treatments appear to be effective at reducing the need for hospital admission in people with bipolar disorder.

The International College of Neuropsychopharmacology (CINP) Treatment Guidelines for Bipolar Disorder in Adults (CINP-BD-2017), Part 1: Background and Methods of the Development of Guidelines

BACKGROUND

This paper includes a short description of the important clinical aspects of Bipolar Disorder with emphasis on issues that are important for the therapeutic considerations, including mixed and psychotic features, predominant polarity, and rapid cycling as well as comorbidity.

METHODS

The workgroup performed a review and critical analysis of the literature concerning grading methods and methods for the development of guidelines.

RESULTS

The workgroup arrived at a consensus to base the development of the guideline on randomized controlled trials and related meta-analyses alone in order to follow a strict evidence-based approach. A critical analysis of the existing methods for the grading of treatment options was followed by the development of a new grading method to arrive at efficacy and recommendation levels after the analysis of 32 distinct scenarios of available data for a given treatment option.

CONCLUSION

The current paper reports details on the design, method, and process for the development of CINP guidelines for the treatment of Bipolar Disorder. The rationale and the method with which all data and opinions are combined in order to produce an evidence-based operationalized but also user-friendly guideline and a specific algorithm are described in detail in this paper.

Using the contribution matrix to evaluate complex study limitations in a network meta-analysis: a case study of bipolar maintenance pharmacotherapy review

Background

Limitations in the primary studies constitute one important factor to be considered in the grading of recommendations assessment, development, and evaluation (GRADE) system of rating quality of evidence. However, in the network meta-analysis (NMA), such evaluation poses a special challenge because each network estimate receives different amounts of contributions from various studies via direct as well as indirect routes and because some biases have directions whose repercussion in the network can be complicated.

Findings

In this report we use the NMA of maintenance pharmacotherapy of bipolar disorder (17 interventions, 33 studies) and demonstrate how to quantitatively evaluate the impact of study limitations using netweight, a STATA command for NMA. For each network estimate, the percentage of contributions from direct comparisons at high, moderate or low risk of bias were quantified, respectively. This method has proven flexible enough to accommodate complex biases with direction, such as the one due to the enrichment design seen in some trials of bipolar maintenance pharmacotherapy.

Conclusions

Using netweight, therefore, we can evaluate in a transparent and quantitative manner how study limitations of individual studies in the NMA impact on the quality of evidence of each network estimate, even when such limitations have clear directions.

Recurrence rates in bipolar disorder: Systematic comparison of long-term prospective, naturalistic studies versus randomized controlled trials

Bipolar disorder (BD) is a recurrent, lifelong illness with high risks of disability and excess mortality. Despite many treatment options with demonstrated short-term efficacy, evidence concerning long-term treatment effectiveness in BD remains limited and the relative value of naturalistic studies versus randomized, controlled trials (RCTs) in its assessment, uncertain. Systematic computer-searching yielded 10 naturalistic studies and 15 RCTs suitable for analysis of recurrence rates and their association with treatments and selected clinical factors. In naturalistic studies (3904 BD subjects, 53.3% women, 85.8% BD-I, mean onset age 29.1, followed up to 2.1 years), the pooled recurrence rate was 55.2% (26.3%/year). In RCTs (4828 subjects, 50.9% women, 96.0% BD-I, mean onset age 23.1, followed up to 1.9 years), the pooled recurrence rate was 39.3% (21.9%/year) with mood-stabilizing drug-treatment versus 60.6% (31.3%/year) with placebo; drug-versus-placebo outcomes favored antipsychotics over lithium, and disfavor an approved anticonvulsant. Depressive episode-polarity increased from 27.7% at intake to 52.0% at first-recurrence (p<0.0001). Recurrence rate (%/year) did not differ by study-type, was greater with younger onset and rapid-cycling, and paradoxically declined with longer observation. In short, recurrences of major affective episodes up to two years during putative mood-stabilizing treatment of BD patients in prospective, naturalistic studies and RCTs were substantial and similar (26.3 vs. 21.9%/year). Episode-polarity shifted strongly toward depressive first-recurrences. These findings support the value of naturalistic studies to complement long-term RCTs, and add to indications that control of depression in BD remains particularly unsatisfactory.

Comparative efficacy and tolerability of pharmacological treatments in the maintenance treatment of bipolar disorder: a systematic review and network meta-analysis

BACKGROUND

Lithium is the established standard in the long-term treatment of bipolar disorder, but several new drugs have been assessed for this indication. We did a network meta-analysis to investigate the comparative efficacy and tolerability of available pharmacological treatment strategies for bipolar disorder.

METHODS

We systematically searched Embase, Medline, PreMedline, PsycINFO, and the Cochrane Central Register of Controlled Trials for randomised controlled trials published before June 28, 2013, that compared active treatments for bipolar disorder (or placebo), either as monotherapy or as add-on treatment, for at least 12 weeks. The primary outcomes were the number of participants with recurrence of any mood episode, and the number of participants who discontinued the trial because of adverse events. We assessed efficacy and tolerability of bipolar treatments using a random-effects network meta-analysis within a Bayesian framework.

FINDINGS

We screened 114 potentially eligible studies and identified 33 randomised controlled trials, published between 1970 and 2012, that examined 17 treatments for bipolar disorder (or placebo) in 6846 participants. Participants assigned to all assessed treatments had a significantly lower risk of any mood relapse or recurrence compared with placebo, except for those assigned to aripiprazole (risk ratio [RR] 0·62, 95% credible interval [CrI] 0·38-1·03), carbamazepine (RR 0·68, 0·44-1·06), imipramine (RR 0·95, 0·66-1·36), and paliperidone (RR 0·84, 0·56-1·24). Lamotrigine and placebo were significantly better tolerated than carbamazepine (lamotrigine, RR 5·24, 1·07-26·32; placebo, RR 3·60, 1·04-12·94), lithium (RR 3·76, 1·13-12·66; RR 2·58, 1·33-5·39), or lithium plus valproate (RR 5·95, 1·02-33·33; RR 4·09, 1·01-16·96).

INTERPRETATION

Although most of the drugs analysed were more efficacious than placebo and generally well tolerated, differences in the quality of evidence and the side-effect profiles should be taken into consideration by clinicians and patients. In view of the efficacy in prevention of both manic episode and depressive episode relapse or recurrence and the better quality of the supporting evidence, lithium should remain the first-line treatment when prescribing a relapse-prevention drug in patients with bipolar disorder, notwithstanding its tolerability profile.

FUNDING

None.