Pharmacotherapy of bipolar depression: an update

Neurocognitive effects of six ketamine infusions and the association with antidepressant effects in treatment-resistant bipolar depression: a preliminary study

Objective

The N-methyl-D-aspartate subtype glutamate receptor antagonist ketamine has rapid antidepressant and antisuicidal effects in treating treatment-resistant bipolar depression (TRBD). The neurocognitive effects of repeated ketamine infusions in TRBD are not known.

Methods

Six intravenous infusions of ketamine (0.5 mg/kg over 40 min) were administered on a Monday–Wednesday–Friday schedule during a 12-day period on 16 patients with TRBD followed by a 2-week observational period. The assessment of neurocognitive function was conducted using the MATRICS Consensus Cognitive Battery at baseline, 13 and 26 days. Tasks were designed to test speed of processing, working memory, visual learning and verbal learning.

Results

A significant improvement was found only in scores of speed of processing (F = 9.9, p = 0.001) after a 2-week observational period, which was accounted for by the improvement of depression symptoms. There were no significant changes over time in terms of working memory, visual learning and verbal learning. Pearson correlation analysis showed that the improvement of depression symptoms through six ketamine infusions was greater among TRBD patients with lower working memory at baseline (r = 0.54, p = 0.03). In multiple regression analysis, the significant correlation was still maintained (beta = 0.67, t = 2.2, p = 0.04).

Conclusion

This preliminary study indicated that six ketamine infusions were not harmful but were slightly beneficial for speed of processing in TRBD. However, this change was mainly accounted for the improvement of depression symptoms over time. Lower baseline working memory appears to be associated with greater antidepressant response after completion of six ketamine infusions in patients with TRBD.

Agomelatine treatment corrects impaired sleep-wake cycle and sleep architecture and increases MT1 receptor as well as BDNF expression in the hippocampus during the subjective light phase of rats exposed to chronic constant light

RATIONALE

Exposure to chronic constant light (CCL) has a detrimental impact on circadian rhythms of motor activity and sleep/wake cycles. Agomelatine is an atypical antidepressant showing a chronotropic activity.

OBJECTIVES

In this study, we explored the role of melatonin (MT) receptors and brain-derived neurotrophic factor (BDNF) in the brain in the mechanism underlying the effects of agomelatine on diurnal variations of motor activity, sleep/wake cycle, and sleep architecture in a rat model of CCL.

METHODS

In Experiment #1, home cage activity was monitored automatically with cameras for a period of 24 h. The diurnal rhythm of MT_1, MT₂ receptors, and BDNF expression in the hippocampus and frontal cortex (FC), was tested using the ELISA test. In Experiment #2, rats were equipped with electroencephalographic (EEG) and electromyographic (EMG) electrodes and recordings were made under basal conditions (12:12 LD cycle + vehicle), LL + vehicle and LL + agomelatine (40 mg/kg/day for 21 days).

RESULTS

The rats exposed to CCL showed an impaired diurnal rhythm of motor activity and sleep/wake cycle with reduced NREM sleep and delta power and increased REM sleep and theta power. The duration and number of episodes of the wake were diminished during the subjective dark phase in this group. The circadian rhythm of MT₁ and MT₂ receptors and their expression did not change in the hippocampus and FC under CCL exposure, while the BDNF levels in the hippocampus decreased during the subjective light phase. Agomelatine restored the diurnal rhythm of motor activity, disturbed sleep/wake cycle, and sleep architecture, which effect was accompanied by an increase in MT₁ receptor and BDNF expression in the hippocampus at 10:00 in CCL rats.

CONCLUSIONS

These findings support the value of agomelatine as an antidepressant that can adjust circadian homeostasis of motor activity and sleep/wake cycle in a CCL model.

Acetylcholinesterase inhibitors and memantine in bipolar disorder: A systematic review and best evidence synthesis of the efficacy and safety for multiple disease dimensions

BACKGROUND

Acetylcholinesterase inhibitors (AceI) and memantine might prove useful in bipolar disorder (BD) given their neuroprotective and pro-cognitive effects, as highlighted by several case reports. We aimed to systematically review the efficacy and safety of AceI and memantine across multiple outcome dimensions in BD.

METHODS

Systematic PubMed and SCOPUS search until 04/17/2015 without language restrictions. Included were randomized controlled trials (RCTs), open label studies and case series of AceI or memantine in BD patients reporting quantitative data on depression, mania, psychotic symptoms, global functioning, or cognitive performance. We summarized results using a best-evidence based synthesis.

RESULTS

Out of 214 hits, 12 studies (RCTs=5, other designs=7, total n=422) were included. Donepezil (studies=5; treated=102 vs. placebo=21): there was strong evidence for no effect on mania and psychotic symptoms; low evidence indicating no effect on depression. Galantamine (studies=3; treated=21 vs. controls=20) (placebo=10, healthy subjects=10): there was strong evidence for no effect on mania; moderate evidence for no effect on depression; low evidence for no effect on global functioning. Memantine (studies=4; treated=152 vs. placebo=88): there was conflicting evidence regarding efficacy for mania, depression and global functioning.

LIMITATIONS

Paucity of RCTs; small sample size studies; heterogeneous design, outcome and patient characteristics.

CONCLUSION

There is limited but converging evidence of no effect of AceI in BD, and conflicting evidence about memantine in BD. Too few studies of mostly medium/low quality and lacking sufficient numbers of patients in specific mood states, especially mania, contributed data, focusing solely on short-term/medium-term treatment, necessitating additional high-quality research to yield more definite results.

Risk of manic switch associated with antidepressant therapy in pediatric bipolar depression

OBJECTIVE

The purpose of this study was to assess the risk of manic switch associated with antidepressants in Medicaid-enrolled pediatric patients with bipolar depression.

METHODS

This retrospective cohort study involved 2003-2007 Medicaid Analytic eXtract (MAX) data from four geographically diverse states. The study sample included children and adolescents (ages 6-18 years) who had received a diagnosis of bipolar disorder on two or more separate occasions or during a hospital discharge, followed by a diagnosis of depression. According to the pharmacotherapy received by these patients in the 30 days around the index bipolar depression diagnosis, patients were categorized into five mutually exclusive groups. Manic switch was defined as having received a diagnosis of mania within 6 weeks after the initiation of bipolar depression treatment. Relative risks of manic switch between antidepressant monotherapy/polytherapy and their alternatives were assessed using Cox proportional hazards model. The robustness of the conventional Cox proportional hazards model toward possible bias caused by unobserved confounders was tested using instrumental variable analysis, and the uncertainty regarding manic switch definition was tested by altering the duration of follow-up.

RESULTS

After applying all the selection criteria, 179 antidepressant monotherapy, 1047 second-generation antipsychotic (SGA) monotherapy, 570 mood stabilizer monotherapy, 445 antidepressant polytherapy, and 1906 SGA-mood stabilizer polytherapy users were identified. In Cox proportional hazard analyses, both antidepressant monotherapy and polytherapy exhibited higher risk of manic switch than their alternatives (antidepressant monotherapy vs. SGA monotherapy, hazard ratio [HR]=2.87 [95% CI: 1.10-7.49]; antidepressant monotherapy vs. mood stabilizer monotherapy, HR=1.41 [95% CI: 0.52-3.80); antidepressant polytherapy vs. SGA-mood stabilizer polytherapy, HR=1.61 [95% CI: 0.90-2.89]). However, only the comparison between antidepressant monotherapy and SGA monotherapy was statistically significant. The instrumental variable analysis did not detect endogeneity of the treatment variables. Extending the follow-up period from 6 weeks to 8 and 12 weeks generated findings consistent with the main analysis.

CONCLUSIONS

Study findings indicated a higher risk of manic switch associated with antidepressant monotherapy than with SGA monotherapy in pediatric patients with bipolar depression. The finding supported the clinical practice of cautious prescribing of antidepressants for brief periods.

Different neural responses to a moral valence decision task in unipolar and bipolar depression

Objectives. Patients affected by bipolar disorder (BP) and major depressive disorder (UP) share the susceptibility to experience depression and differ in their susceptibility to mania, but clinical studies suggest that the biological substrates of the two disorders could influence the apparently similar depressive phases. The few brain imaging studies available described different brain metabolic and neural correlates of UP and BP. Methods. We studied the BOLD neural response to a moral valence decision task targeting the depressive biases in information processing in 36 subjects (14 BP, 11 UP, and 11 controls). Results. Main differences between UP and controls and between UP and BP were detected in left ventrolateral prefrontal cortex (PFC, BA 47). Neural responses of BP patients differed from those of control subjects in multiple brain areas, including anterior cingulate cortex (ACC) and medial PFC, bilateral dorsolateral PFC, temporal cortex and insula, and parietal and occipital cortex. Conclusions. Our results are in agreement with hypotheses of dysfunctions in corticolimbic circuitries regulating affects and emotions in mood disorders and suggest that specific abnormalities, particularly in ventrolateral PFC, are not the same in UP and BP depression.

The utilization of psychopharmacological treatment and medication adherence among Medicaid enrolled children and adolescents with bipolar depression

BACKGROUND

To examine the psychotropic medication utilization and compare adherence to treatment regimens in pediatric bipolar depression patients.

METHODS

2003-2007 MAX data from four geographically diverse states were used. According to the regimen received by the patients (6-18 years) in the first month after the index bipolar depression diagnosis, patients were categorized into six mutually exclusive groups. The month to month change of treatment regimen in each group was then assessed during the 6 month post-index bipolar depression diagnosis. Adherence to each regimen was measured as continuation of the initial regimen, switch to a new regimen, augmentation with medication from a different therapeutic category, and discontinuation of all pharmacotherapies. Repeated measure analysis was conducted to compare the trend of each adherence measure across the study groups.

RESULTS

Of the 5,460 subjects identified, 15.39% received antipsychotic monotherapy, 9.43% received mood stabilizer monotherapy, 5.77% received antidepressant monotherapy, 26.48% received mood stabilizer-antipsychotic polytherapy, 22.51% received antidepressant polytherapy, and 19.89% received antipsychotic-mood stabilizer-antidepressant polytherapy. At the end of the follow-up period, over 50% of the 1st month polytherapy users and less than 50% of the monotherapy users were continuing their initial regimen. Repeated measure analysis using antipsychotic monotherapy as the reference group suggested differences in trend slopes (p<0.05).

LIMITATIONS

In absence of structured clinical evaluation, bipolar disorder diagnoses cannot be ascertained in this study.

CONCLUSIONS

Bipolar depression patients were predominantly treated with combinations of psychotropic drugs. Potentially questionable practice, such as antidepressant monotherapy was used only in a small fraction of patients. Combination regimens had better adherence as compared to monotherapies.

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.

The effect of melatonergic and non-melatonergic antidepressants on sleep: weighing the alternatives

In DSM-IV the occurrence of disturbed sleep is one of the principal diagnostic criteria for major depressive disorder (MDD). Further, there is evidence of reciprocity between the two conditions such that, even in the absence of current depressive symptoms, disturbed sleep often predicts their development. The present review discusses the effects of antidepressants on sleep and evaluates the use of the recently developed melatonin agonist-selective serotonin antagonists on sleep and depression. Although many antidepressants such as the tricyclics, monoamine oxidase inhibitors, serotonin-norepinephrine reuptake inhibitors, several serotonin receptor antagonists and selective serotonin reuptake inhibitors (SSRIs) have all been found successful in treating depression, their use is often associated with a disruptive effect on sleep. SSRIs, currently the most widely prescribed of the antidepressants, are well known for their instigation or exacerbation of insomnia. The recently introduced novel melatonin agonist and selective serotonin antagonist antidepressant, agomelatine, which has melatonin MT(1) and MT(2) receptor agonist and 5-HT(2c) antagonist properties, has been useful in treating patients with MDD. Its rapid onset of action and effectiveness in improving the mood of depressed patients has been attributed to its ability to improve sleep quality. These properties underline the use of melatonin analogues as a promising alternative for the treatment of depression.

Treatment of bipolar disorder: new perspectives

Treatment of bipolar disorder (BD) has traditionally focused on alleviation of acute symptoms and prevention of future recurrences. Current treatment guide-lines advocate more or less similar treatment algorithms for all patients. Such approach largely ignores the clinical, genetic, and pathophysiological heterogeneity of BD, which makes certain patients more (or less) likely to respond to specific treatments. Variables such as family history, comorbidity, course of illness, quality and duration of previous remissions, physical and medical comorbidity, and side-effects may help in selecting the most effective treatment for an individual patient, yet their value is not recognized by current algorithms. As well, polymorphisms of specific genes may prove useful in predicting treatment outcome and/or understanding the pharmacological mechanisms of mood stabilization. Novel molecular targets have recently emerged from studies of mechanisms of action of available mood stabilizers. They include inhibitors of protein kinase C, inhibitors of glycogen synthase kinase, or medications modulating glutamatergic neurotransmission. As well, treatment targets are moving beyond acute symptoms and prevention of mood episodes. Cognitive deficits, persistence of residual symptoms, and increased mortality of BD are recognized as important for outcome of BD, yet are not always adequately addressed by traditional treatments.

Bipolar depression: trial-based insights to guide patient care

For the majority of patients with bipolar disorder, major depressive episodes represent the most debilitating and difficult-to-treat illness dimension. Patients spend significantly more time depressed than manic or hypomanic, and attempt suicide more frequently during this illness phase, yet the availability of treatments remains limited. The discovery of more effective therapeutics for managing depressive episodes is arguably the greatest unmet need in bipolar disorder. This article provides an evidence-based summary of pharmacological treatments for the acute and longitudinal management of bipolar depression. Clinical trial results are reviewed for a diverse array of compounds, inclusive of traditional mood stabilizers (eg, lithium and divalproex), atypical antipsychotics, unimodal antidepressants, and modafinil. Where applicable, differences in efficacy across compounds are examined through discussion of number needed to treat and effect size determinations. A pragmatic clinical approach is presented for management of the depressed phase of bipolar disorder.

[Cognitive-behavioral therapy for depression]

OBJECTIVE

To describe the use of cognitive techniques and to review studies on the efficacy of CBT in the treatment of depression.

METHOD

A non-systematic review of the literature of original studies complemented with data from meta-analyses and specialized textbooks.

RESULTS

The fundamentals of cognitive-behavioral therapy in the treatment of depression are described and the evidence of short- and long-term efficacy is reviewed. The use of pharmacological therapy in conjunction with CBT is also discussed.

CONCLUSIONS

CBT in the treatment of depression is one of the therapeutic modalities with the highest empirical evidence of efficacy, whether applied alone or in combination with pharmacotherapy.

Aripiprazole monotherapy in nonpsychotic bipolar I depression: results of 2 randomized, placebo-controlled studies

Although most treatment research on bipolar disorder has focused on mania, depressive episodes occur more frequently among patients with bipolar disorder. Here, we report the results of 2 identically designed, 8-week, multicenter, randomized, double-blind, placebo-controlled studies (CN138-096 and CN138-146) to evaluate the efficacy and safety of aripiprazole monotherapy in outpatients with bipolar I disorder experiencing a major depressive episode without psychotic features. Patients were randomized to placebo or aripiprazole (initiated at 10 mg/d, then flexibly dosed at 5-30 mg/d based on clinical effect and tolerability). The primary end point was mean change from baseline to Week 8 (last observation carried forward) in the Montgomery-Asberg Depression Rating Scale total score. In Studies 1 and 2, respectively, 186 and 187 patients were randomized to aripiprazole, and 188 and 188 to placebo. Although statistically significant differences were observed during Weeks 1 to 6, aripiprazole did not achieve statistical significance versus placebo at Week 8 in either study in the change in Montgomery-Asberg Depression Rating Scale total (primary end point). In addition, despite early statistical separation on the Clinical Global Impressions Bipolar Version Severity of Illness-Depression score (key secondary end point), aripiprazole was not superior to placebo at end point. Aripiprazole was associated with a higher incidence of akathisia, insomnia, nausea, fatigue, restlessness, and dry mouth versus placebo. More patients discontinued with aripiprazole versus placebo in Study 1 (46.8% vs 35.1%) and Study 2 (41.2% vs 29.8%). Aripiprazole monotherapy-as dosed in this study design-was not significantly more effective than placebo in the treatment of bipolar depression at end point (Week 8).

Quetiapine: a review of its use in the treatment of bipolar depression

Quetiapine (Seroquel) is the only atypical antipsychotic approved in the US for use as monotherapy in both bipolar mania and depression, offering potential compliance advantages. Monotherapy with oral quetiapine 300 mg/day is effective in the treatment of patients with bipolar I or II depression. Rapid and sustained improvements in depressive and anxiety symptoms are seen with quetiapine, as well as improvements in health-related quality of life (HR-QOL). Quetiapine is generally well tolerated in bipolar depression and is not associated with an increased risk of treatment-emergent mania. Thus, despite the current lack of data from active comparator trials, quetiapine monotherapy should be considered a first-line option for the acute treatment of bipolar depression.

Physiogenomic association of statin-related myalgia to serotonin receptors

We employed physiogenomic analyses to investigate the relationship between myalgia and selected polymorphisms in serotonergic genes, based on their involvement with pain perception and transduction of nociceptive stimuli. We screened 195 hypercholesterolemic, statin-treated patients, all of whom received either atorvastatin, simvastatin, or pravastatin. Patients were classified as having no myalgia, probable myalgia, or definite myalgia, and assigned a myalgia score of 0, 0.5, or 1, respectively. Fourteen single nucleotide polymorphisms (SNPs) were selected from candidates within the 5-HT receptor gene families [5a-hydroxytryptamine receptor genes (HTR) 1D, 2A, 2C, 3A, 3B, 5A, 6, 7] and the serotonin transporter gene (SLC6A4). SNPs in the HTR3B and HTR7 genes, rs2276307 and rs1935349, respectively, were significantly associated with the myalgia score. Individual differences in pain perception and nociception related to specific serotonergic gene variants may affect the development of myalgia in statin-treated patients.