Re-evaluation of randomized control trials of lithium monotherapy: a cohort effect

The assessment of resistance to antidepressant treatment: Rationale for the Antidepressant Treatment History Form: Short Form (ATHF-SF)

There is considerable diversity in how treatment-resistant depression (TRD) is defined. However, every definition incorporates the concept that patients with TRD have not benefited sufficiently from one or more adequate trials of antidepressant treatment. This review examines the issues fundamental to the systematic evaluation of antidepressant treatment adequacy and resistance. These issues include the domains of interventions deemed effective in treatment of major depressive episodes (e.g., pharmacotherapy, brain stimulation, and psychotherapy), the subgroups of patients for whom distinct adequacy criteria are needed (e.g., bipolar vs. unipolar depression, psychotic vs. nonpsychotic depression), whether trials should be rated dichotomously as adequate or inadequate or on a potency continuum, whether combination and augmentation strategies require specific consideration, and the criteria used to evaluate the adequacy of treatment delivery (e.g., dose, duration), trial adherence, and clinical outcome. This review also presents the Antidepressant Treatment History Form: Short-Form (ATHF-SF), a completely revised version of an earlier instrument, and details how these fundamental issues were addressed in the ATHF-SF.

An Oldie but Goodie: Lithium in the Treatment of Bipolar Disorder through Neuroprotective and Neurotrophic Mechanisms

Lithium has been used for the treatment of bipolar disorder (BD) for the last sixty or more years, and recent studies with more reliable designs and updated guidelines have recommended lithium to be the treatment of choice for acute manic, mixed and depressive episodes of BD, along with long-term prophylaxis. Lithium’s specific mechanism of action in mood regulation is progressively being clarified, such as the direct inhibition on glycogen synthase kinase 3β, and its various effects on neurotrophic factors, neurotransmitters, oxidative metabolism, apoptosis, second messenger systems, and biological systems are also being revealed. Furthermore, lithium has been proposed to exert its treatment effects through mechanisms associated with neuronal plasticity. In this review, we have overviewed the clinical aspects of lithium use for BD, and have focused on the neuroprotective and neurotrophic effects of lithium.

Maintenance efficacy designs in psychiatry: Randomized discontinuation trials - enriched but not better

Introduction

Although classical randomized clinical trials (RCTs) are the gold standard for proof of drug efficacy, randomized discontinuation trials (RDTs), sometimes called “enriched” trials, are used increasingly, especially in psychiatric maintenance studies.

Methods

A narrative review of two decades of experience with RDTs.

Results

RDTs in psychiatric maintenance trials tend to use a dependent variable as a predictor: treatment response. Treatment responders are assessed for treatment response. This tautology in the logic of RDTs renders them invalid, since the predictor and the outcome are the same variable. Although RDTs can be designed to avoid this tautologous state of affairs, like using independent predictors of outcomes, such is not the case with psychiatric maintenance studies

Further, purported benefits of RDTs regarding feasibility were found to be questionable. Specifically, RDTs do not enhance statistical power in many settings, and, because of high dropout rates, produce results of questionable validity. Any claimed benefits come with notably reduced generalizability.

Conclusions

RDTs appear to be scientifically invalid as used in psychiatric maintenance designs. Their purported feasibility benefits are not seen in actual trials for psychotropic drugs. There is warrant for changes in federal policy regarding marketing indications for maintenance efficacy using the RDT design.

Pharmacological treatment and risk of psychiatric hospital admission in bipolar disorder

BackgroundClinical trials have examined the efficacy of drugs to prevent relapse in patients with bipolar disorder, however, their design often limits generalisation to routine clinical practice.AimsTo estimate the effectiveness of drugs used for maintenance treatment in bipolar disorder.MethodWe used national registers to identify 35 022 individuals diagnosed with bipolar disorder and information on lithium, valproate, carbamazepine, lamotrigine, quetiapine and olanzapine treatment from 2006 to 2009. The main outcome was psychiatric hospital admissions. We used stratified cox regression to compare periods on and off medication within the same individual.ResultsMedication with lithium, valproate, lamotrigine, olanzapine and quetiapine was associated with reduced rates of admission to hospital. Lithium was more effective than quetiapine and olanzapine. The effects of specific drugs depended on the polarity of the mood episode.ConclusionsOur findings complement results from randomised controlled trails, but suggest that lithium is more effective than both quetiapine and olanzapine in routine clinical practice.

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.

Maintenance treatment study designs in bipolar disorder: do they demonstrate that atypical neuroleptics (antipsychotics) are mood stabilizers?

In this conceptual review we argue that by certifying some of the atypical neuroleptics (or, if one prefers, antipsychotics) as indicated for the 'maintenance' treatment of bipolar disorder, the US FDA has created confusion in the field. These maintenance indications are based on studies using a 'relapse prevention' design, a design that does not address whether the agents tested can prevent new episodes of illness, i.e. recurrence prevention or true prophylaxis. We found that the relapse prevention design fails to prove that these agents are mood stabilizers because patients are pre-selected to respond to the study drug for an acute mood episode (mania) and when they relapse, they do so into an episode of the same polarity (i.e. mania). We believe that this represents withdrawal into the same mood episode that patients experienced before the maintenance study began, rather than prevention of a new mood episode, as research into the natural history of bipolar disorder indicates that such new episodes typically are of the opposite polarity. Thus, the inability of neuroleptics to prevent depression in such maintenance studies reflects the general inability to prevent any new mood episode recurrence (which we believe should be defined as 6 months or longer after the index episode). If one defines a mood stabilizer, as we do, as a drug that prevents new episodes of mania and depression in monotherapy, then these studies do not show that atypical neuroleptics are mood stabilizers. Future maintenance research studies in bipolar disorder should use the prophylaxis design (i.e. without pre-selection of drug responders), rather than the relapse prevention design.

Aripiprazole in the maintenance treatment of bipolar disorder: a critical review of the evidence and its dissemination into the scientific literature

BACKGROUND

Aripiprazole, a second-generation antipsychotic medication, has been increasingly used in the maintenance treatment of bipolar disorder and received approval from the U.S. Food and Drug Administration for this indication in 2005. Given its widespread use, we sought to critically review the evidence supporting the use of aripiprazole in the maintenance treatment of bipolar disorder and examine how that evidence has been disseminated in the scientific literature.

METHODS AND FINDINGS

We systematically searched multiple databases to identify double-blind, randomized controlled trials of aripiprazole for the maintenance treatment of bipolar disorder while excluding other types of studies, such as open-label, acute, and adjunctive studies. We then used a citation search to identify articles that cited these trials and rated the quality of their citations. Our evidence search protocol identified only two publications, both describing the results of a single trial conducted by Keck et al., which met criteria for inclusion in this review. We describe four issues that limit the interpretation of that trial as supporting the use of aripiprazole for bipolar maintenance: (1) insufficient duration to demonstrate maintenance efficacy; (2) limited generalizability due to its enriched sample; (3) possible conflation of iatrogenic adverse effects of abrupt medication discontinuation with beneficial effects of treatment; and (4) a low overall completion rate. Our citation search protocol yielded 80 publications that cited the Keck et al. trial in discussing the use of aripiprazole for bipolar maintenance. Of these, only 24 (30%) mentioned adverse events reported and four (5%) mentioned study limitations.

CONCLUSIONS

A single trial by Keck et al. represents the entirety of the literature on the use of aripiprazole for the maintenance treatment of bipolar disorder. Although careful review identifies four critical limitations to the trial's interpretation and overall utility, the trial has been uncritically cited in the subsequent scientific literature. Please see later in the article for the Editors' Summary.