Bipolar depression: trial-based insights to guide patient care

Double-blind, placebo-controlled trial of pioglitazone for bipolar depression

BACKGROUND

Objective of the present study was to conduct an 8-week double-blind, randomized, placebo-controlled trial to test the efficacy of pioglitazone in the treatment of bipolar depression.

METHODS

38 outpatients with bipolar disorder and current major depressive episode were randomized to pioglitazone (15-45 mg/day) or placebo. The use of concomitant mood stabilizers, antipsychotics, and antidepressants was permitted. The primary outcome measure was the 30-item Inventory of Depressive Symptomatology, Clinician Rated (IDS-C30) total score change from baseline to endpoint. Laboratory evaluations, including serum level of inflammatory and metabolic biomarkers, were conducted.

RESULTS

37 subjects were analyzed for efficacy (1 subject had no follow-up data). Mean reduction from baseline to week 8 in IDS-C30 score was-6.59 for pioglitazone and -11.63 for placebo. Mixed effects modeling indicated borderline statistically significant difference between the two groups (p = 0.056) in favor of placebo. On analysis of inflammatory and metabolic markers, a statistically significant negative correlation was noted between change in leptin levels and change in depression scores in the pioglitazone group (r = -0.61, p = 0.047) but not in the placebo group, the significance of which is unclear as the study failed to demonstrate antidepressant efficacy of pioglitazone over placebo. No serious adverse effects were reported, and pioglitazone was well-tolerated.

LIMITATIONS

small sample size with inadequate power, concomitant use of other psychotropic medications, and lack of statistical adjustment for multiple testing.

CONCLUSION

Current study does not support the antidepressant efficacy of pioglitazone in the treatment of bipolar depression. (240 words).

PPAR-γ agonism as a modulator of mood: proof-of-concept for pioglitazone in bipolar depression

BACKGROUND

Insulin resistance and other cardio-metabolic risk factors predict increased risk of depression and decreased response to antidepressant and mood stabilizer treatments. This proof-of-concept study tested whether administration of an insulin-sensitizing peroxisome proliferator-activated receptor (PPAR)-γ agonist could reduce bipolar depression symptom severity. A secondary objective was to determine whether levels of highly sensitive C-reactive protein and interleukin (IL)-6 predicted treatment outcome.

METHODS

Patients (n = 34) with bipolar disorder (I, II, or not otherwise specified) and metabolic syndrome/insulin resistance who were currently depressed (Quick Inventory of Depressive Symptoms [QIDS] total score ≥11) despite an adequate trial of a mood stabilizer received open-label, adjunctive treatment with the PPAR-γ agonist pioglitazone (15-30 mg/day) for 8 weeks. The majority of participants (76 %, n = 26) were experiencing treatment-resistant bipolar depression, having already failed two mood stabilizers or the combination of a mood stabilizer and a conventional antidepressant.

RESULTS

Supporting an association between insulin sensitization and depression severity, pioglitazone treatment was associated with a decrease in the total Inventory of Depressive Symptomatology (IDS-C30) score from 38.7 ± 8.2 at baseline to 21.2 ± 9.2 at week 8 (p < 0.001). Self-reported depressive symptom severity and clinician-rated anxiety symptom severity significantly improved over 8 weeks as measured by the QIDS (p < 0.001) and Structured Interview Guide for the Hamilton Anxiety Scale (p < 0.001), respectively. Functional improvement also occurred as measured by the change in total score on the Sheehan Disability Scale (-17.9 ± 3.6; p < 0.001). Insulin sensitivity increased from baseline to week 8 as measured by the Insulin Sensitivity Index derived from an oral glucose tolerance test (0.98 ± 0.3; p < 0.001). Higher baseline levels of IL-6 were associated with greater decrease in depression severity (parameter estimate β = -3.89, standard error [SE] = 1.47, p = 0.015). A positive correlation was observed between improvement in IDS-C30 score and change in IL-6 (r = 0.44, p < 0.01).

CONCLUSIONS

Open-label administration of the PPAR-γ agonist pioglitazone was associated with improvement in depressive symptoms and reduced cardio-metabolic risk. Reduction in inflammation may represent a novel mechanism by which pioglitazone modulates mood. (ClinicalTrials.gov Identifier: NCT00835120).

Lamotrigine as add-on treatment to lithium and divalproex: lessons learned from a double-blind, placebo-controlled trial in rapid-cycling bipolar disorder

OBJECTIVES

A substantial portion of the morbidity associated with rapid-cycling bipolar disorder (RCBD) stems from refractory depression. This study assessed the antidepressant effects of lamotrigine as compared with placebo when used as add-on therapy for rapid-cycling bipolar depression non-responsive to the combination of lithium plus divalproex.

METHODS

During Phase 1 of this trial, hypomanic, manic, mixed, and/or depressed outpatients (n = 133) aged 18-65 years with DSM-IV RCBD type I or II were initially treated with the open combination of lithium and divalproex for up to 16 weeks. During Phase 2, subjects who did not meet the criteria for stabilization (n = 49) (i.e., remained in or cycled into the depressed phase) were randomly assigned to double-blind, adjunctive lamotrigine (n = 23) or adjunctive placebo (n = 26). The primary endpoint was the mean change in depression symptom severity from the beginning of Phase 2 to the end of Phase 2 (week 12) on the Montgomery-Åsberg Depression Rating Scale (MADRS) total score. Data were analyzed by analysis of covariance with last observation carried forward and a mixed-models analysis.

RESULTS

  During Phase 1, a high rate of study discontinuations occurred due to intolerable side effects (13/133; 10%) and study non-adherence (22/133; 17%). Only 14% (19/133) stabilized on the open combination of lithium and divalproex. Among the 49 (37%) patients randomized to the double-blind adjunctive treatment phase, mean ± standard error change from baseline on the MADRS total score was -8.5 ± 1.7 points for lamotrigine and -9.1 ± 1.5 points for placebo (p = not significant; mixed-models analysis). No significant differences were observed in the rates of response, remission, or bimodal response between lamotrigine and placebo.

CONCLUSIONS

The poor tolerability, lack of efficacy, and high rate of early discontinuation with the combination of lithium and divalproex suggests this regimen was ineffective for the majority of patients with RCBD. Among patients who did not stabilize on lithium and divalproex, the addition of lamotrigine was no more effective than placebo in reducing depression severity. The findings suggest an opportunity for several design modifications to enhance signal detection in future trials of RCBD. The main limitation is the small number of subjects randomized to double-blind treatment.

Lithium use in bipolar disorder: Summary of evidence for acute mania, acute depression, and maintenance treatment

Lithium has been used for more than 50 years for the treatment of bipolar disorder. There is a substantial body of literature about use of lithium in this condition, much of it with conflicting results. Many guidelines and algorithms support the use of lithium for treatment of episodes of acute mania and depression. However, additional research exploring prevention of depressive and manic relapse, treatment of acute depression, and use of combination treatments are needed.

Methods to limit attrition in longitudinal comparative effectiveness trials: lessons from the Lithium Treatment - Moderate dose Use Study (LiTMUS) for bipolar disorder

BACKGROUND

High attrition rates, which occur frequently in longitudinal clinical trials of interventions for bipolar disorder, limit the interpretation of results.

PURPOSE

The aim of this article is to present design approaches that limited attrition in the Lithium Treatment - Moderate dose Use Study (LiTMUS) for bipolar disorder.

METHODS

LiTMUS was a 6-month randomized, longitudinal multisite comparative effectiveness trial that enrolled bipolar participants who were at least mildly ill. Participants were randomized to either low to moderate doses of lithium or no lithium; other treatments needed for mood stabilization were administered in a guideline-informed, empirically supported, and personalized fashion to participants in both treatment arms.

RESULTS

Components of the study design that may have contributed to low attrition (16%) among 283 participants randomized included the use of (1) an intent-to-treat design, (2) a randomized adjunctive single-blind design, (3) participant reimbursement, (4) assessment of intent to attend the next study visit (included a discussion of attendance obstacles when intention was low), (5) quality care with limited participant burden, and (6) target windows for study visits.

LIMITATIONS

The relationships between attrition and effectiveness and tolerability of treatment have not been analyzed yet.

CONCLUSIONS

These components of the LiTMUS design may have limited attrition and may inform the design of future randomized comparative effectiveness trials among similar patients and those from other difficult-to-follow populations.

Treatment options for bipolar depression: a systematic review of randomized, controlled trials

This meta-analysis examined the effectiveness of treatments of bipolar depression. Trials were identified using the MEDLINE, EMBASE, http://www.clinicaltrials.gov, and Cochrane databases (1993 to July 2008). The outcome measures included mean change in Montgomery-Asberg Depression Rating Scale (MADRS) or Hamilton Depression Rating Scale (HAM-D) total scores, and rates of response and remission. Overall, 19 publications were included. Medications included quetiapine, lamotrigine, paroxetine, lithium, olanzapine, aripiprazole, phenelzine, and divalproex. The most trials were identified for quetiapine (5) and lamotrigine (6). Not all medications were associated with symptomatic improvement (significant reduction in MADRS/HAM-D total scores vs placebo), with lamotrigine, paroxetine, aripiprazole, and lithium not being different from placebo. Highest reductions in MADRS scores versus placebo were reported for the olanzapine-fluoxetine combination (1 trial: -6.6; 95% confidence interval [CI], -9.59 to -3.61; P = 0.000) and quetiapine monotherapy (5 trials: for 300 mg/d, -4.8; 95% CI, -6.18 to -3.49; P = 0.000; for 600 mg/d, -4.8; 95% CI, -6.22 to -3.28; P = 0.000), with quetiapine monotherapy also showing the highest reduction in HAM-D scores (4 trials: -4.0; 95% CI, -5.0 to -2.9; P = 0.000). All medications except paroxetine, lithium, aripiprazole, and phenelzine significantly improved the ratio of probabilities of response (overall rate, 1.31; 95% CI, 1.22-1.40) and remission (1.32; 95% CI, 1.20-1.45) versus placebo. Variability in efficacy exists between treatments of bipolar depression. Quetiapine and the olanzapine-fluoxetine combination showed the greatest symptomatic improvement. Efficacy considerations will need to be balanced against safety and tolerability of the individual agents.

Bipolar depression: overview and commentary

Depressive phases are the most prevalent component of bipolar disorders, even with modern treatment. Bipolar depressive morbidity is often misdiagnosed and is limited in response to available treatments. These conditions are especially debilitating and are associated with psychiatric comorbidity, substance abuse, functional disability, and increased mortality owing to early suicide and accidents, and later medical illnesses. There is growing awareness that bipolar depression is one of the greatest challenges in modern psychiatry. It is essential to differentiate various forms of depression, dysthymia, and dysphoric mixed states of bipolar disorders from the clinical features of more common, unipolar major depressive disorders. In bipolar depression, antidepressant responses often are unsatisfactory, and these agents probably are overused. Emerging treatments, including several anticonvulsant and modern antipsychotic drugs, as well as lithium-alone or in selected combinations-are partially effective for bipolar depression. Interest in recognizing bipolar depression and seeking more effective, specific, and safer treatments for it are growing.

An update on the treatment of bipolar depression

BACKGROUND

Although depression accounts for a large part of the burden associated with bipolar disorder, its drug treatment has been under-studied.

OBJECTIVE

To provide the best available evidence supporting the pharmacotherapy of bipolar depression.

METHODS

A systematic review was conducted, focusing on randomized, controlled trials (RCTs) and meta-analyses.

RESULTS/CONCLUSIONS

Despite FDA approval of both the olanzapine-fluoxetine combination and quetiapine for the treatment of acute bipolar depression, independent RCTs (i.e., not trials conducted 'under the umbrella' of a drug company) have not found any drug to have antidepressant effects similar to those seen in unipolar depression. A practice-based suggestion, valuable for both short- and long-term treatment, might be to have a background of mood stabilizers and to add drugs, following one of several treatment options, trusting to find a drug with a degree of effectiveness by trial and error. The list of drugs that could be used would include all the current antidepressants, the olanzapine-fluoxetine combination and probably quetiapine too. Special features and situations might also influence treatment options.