Augmentation of antidepressants with atypical antipsychotics for treatment-resistant major depressive disorder

Therapeutic armamentarium for treating depression

Depressive disorders are highly prevalent and are a leading cause of disability, morbidity, and mortality worldwide; however, they often remain undertreated or untreated. This article provides a broad overview of the many strategies for treating depression. More than 24 antidepressant medications and depression-focused psychotherapies are available as first-choice options for treating depression. When patients have not had a satisfactory treatment response, the 2 main strategies are switching to an alternative antidepressant therapy or adding a second antidepressant therapy. A large number of medication combinations have been reported in the literature, and some have been shown to be effective in controlled studies. Nonstandard alternatives to conventional antidepressant treatments include exercise, light therapy, sleep deprivation, and various complementary and alternative therapies. For more chronic and refractory forms of depression, various neuromodulation therapies are available or are being investigated. Because depressive disorders are common in primary care and other medical settings, medical practitioners should be aware of the therapeutic armamentarium available for treating depression.

Affinity of aporphines for the human 5-HT2A receptor: insights from homology modeling and molecular docking studies

Analogs of nantenine were docked into a modeled structure of the human 5-HT(2A) receptor using ICM Pro, GLIDE, and GOLD docking methods. The resultant docking scores were used to correlate with observed in vitro apparent affinity (K(e)) data. The GOLD docking algorithm when used with a homology model of 5-HT(2A), based on a bovine rhodopsin template and built by the program MODELLER, gives results which are most in agreement with the in vitro results. Further analysis of the docking poses among members of a C1 alkyl series of nantenine analogs, indicate that they bind to the receptor in a similar orientation, but differently than nantenine. Besides an important interaction between the protonated nitrogen of the C1 alkyl analogs and residue Asp155, we identified Ser242, Phe234, and Gly238 as key residues responsible for the affinity of these compounds for the 5-HT(2A) receptor. Specifically, the ability of some of these analogs to establish a H-bond with Ser242 and hydrophobic interactions with Phe234 and Gly238 appears to explain their enhanced affinity as compared to nantenine.

In the clinic. Depression

This issue provides a clinical overview of depression focusing on prevention, diagnosis, treatment, practice improvement, and patient information. Readers can complete the accompanying CME quiz for 1.5 credits. Only ACP members and individual subscribers can access the electronic features of In the Clinic. Non-subscribers who wish to access this issue of In the Clinic can elect "Pay for View." Subscribers can receive 1.5 category 1 CME credits by completing the CME quiz that accompanies this issue of In the Clinic. The content of In the Clinic is drawn from the clinical information and education resources of the American College of Physicians (ACP), including PIER (Physicians' Information and Education Resource) and MKSAP (Medical Knowledge and Self Assessment Program). Annals of Internal Medicine editors develop In the Clinic from these primary sources in collaboration with the ACP's Medical Education and Publishing division and with assistance of science writers and physician writers. Editorial consultants from PIER and MKSAP provide expert review of the content. Readers who are interested in these primary resources for more detail can consult www.acponline.org, http://pier.acponline.org, and other resources referenced within each issue of In the Clinic.

Pharmacologic approaches to treatment resistant depression: a re-examination for the modern era

IMPORTANCE OF THE FIELD

Treatment-resistant depression (TRD) is common and debilitating. Initial treatment is often insufficient to achieve full remission in a given depressive episode, resulting in more frequent episodes, worsened severity, and major disability.

AREAS COVERED IN THIS REVIEW

This review surveys literature on the diagnosis and pharmacological management of TRD in light of recent developments. Evidence regarding commonly used treatment options is critically examined and key recommendations are offered. The review ends by considering drugs acting on the melatonin, acetylcholine, and glutamate systems that hold promise as future options for TRD.

WHAT THE READER WILL GAIN

Recent trends and research findings have impacted how the evidence supporting different approaches to TRD should be evaluated. For example, many earlier TRD studies employed tricyclics as the primary antidepressant, but tricyclics have now been superseded by selective serotonin reuptake inhibitors (SSRIs) in routine clinical practice. This deficiency has been addressed by the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study, the largest effectiveness study of TRD ever conducted. However, design characteristics of the STAR*D study preclude simple comparisons with earlier studies.

TAKE HOME MESSAGE

A shortcoming of most treatment recommendations for TRD is their reliance on older studies that do not reflect the current preeminence of SSRIs in clinical practice. This has distorted the prioritization of pharmacological strategies for TRD. Efforts to correct this distortion with effectiveness research, designed to better reflect current practice trends, require critical consideration of the strengths and limitations of this approach.

Selective serotonin reuptake inhibitors potentiate the rapid antidepressant-like effects of serotonin4 receptor agonists in the rat

BACKGROUND

We have recently reported that serotonin(4) (5-HT(4)) receptor agonists have a promising potential as fast-acting antidepressants. Here, we assess the extent to which this property may be optimized by the concomitant use of conventional antidepressants.

METHODOLOGY/PRINCIPAL FINDINGS

We found that, in acute conditions, the 5-HT(4) agonist prucalopride was able to counteract the inhibitory effect of the selective serotonin reuptake inhibitors (SSRI) fluvoxamine and citalopram on 5-HT neuron impulse flow, in Dorsal Raphé Nucleus (DRN) cells selected for their high (>1.8 Hz) basal discharge. The co-administration of both prucalopride and RS 67333 with citalopram for 3 days elicited an enhancement of DRN 5-HT neuron average firing rate, very similar to what was observed with either 5-HT(4) agonist alone. At the postsynaptic level, this translated into the manifestation of a tonus on hippocampal postsynaptic 5-HT(1A) receptors, that was two to three times stronger when the 5-HT(4) agonist was combined with citalopram. Similarly, co-administration of citalopram synergistically potentiated the enhancing effect of RS 67333 on CREB protein phosphorylation within the hippocampus. Finally, in the Forced Swimming Test, the combination of RS 67333 with various SSRIs (fluvoxamine, citalopram and fluoxetine) was more effective to reduce time of immobility than the separate administration of each compound.

CONCLUSIONS/SIGNIFICANCE

These findings strongly suggest that the adjunction of an SSRI to a 5-HT(4) agonist may help to optimize the fast-acting antidepressant efficacy of the latter.

Trends in antipsychotic drug use by very young, privately insured children

OBJECTIVE

This study describes recent trends and patterns in antipsychotic treatment of privately insured children aged 2 through 5 years.

METHOD

A trend analysis is presented of antipsychotic medication use (1999-2001 versus 2007) stratified by patient characteristics. Data are analyzed from a large administrative database of privately insured individuals. Participants were privately insured children, aged 2 through 5 years, with 12 months of continuous service enrollment in 1999-2001 (N = 400,196) or 2007 (N = 755,793). The main outcomes are annualized rates of antipsychotic use and adjusted rate ratios (ARR) of year effect on rate of antipsychotic use adjusted for age, sex, and treated mental disorder.

RESULTS

The annualized rate of any antipsychotic use per 1,000 children increased from 0.78 (95% confidence interval [CI] 0.69-0.88) (1999-2001) to 1.59 (95% CI 1.50-1.68) (2007) (ARR 1.76, 95% CI 1.56-2.00). Significant increases in antipsychotic drug use were evident for boys (ARR 1.66, 95% CI 1.44-1.90) and girls (ARR 2.26, 95% CI 1.70-3.01) and for children diagnosed with several different psychiatric disorders. Among antipsychotic-treated children in the 2007 sample, pervasive developmental disorder or mental retardation (28.2%), attention deficit/hyperactivity disorder (ADHD) (23.7%), and disruptive behavior disorder (12.9%) were the most common clinical diagnoses. Fewer than one-half of antipsychotic-treated young children received a mental health assessment (40.8%), a psychotherapy visit (41.4%), or a visit with a psychiatrist (42.6%) during the year of antipsychotic use.

CONCLUSIONS

Despite increasing rates of antipsychotic use by very young children, provision of formal mental health services remains sparse. These service patterns highlight a critical need to improve the availability of specialized and well integrated mental health care for very young children with serious mental health problems.

Critical appraisal and update on the clinical utility of agomelatine, a melatonergic agonist, for the treatment of major depressive disease in adults

This article describes the pharmacology of the novel atypical antidepressant drug agomelatine, critically reviews and evaluates its clinical use for the treatment of major depression, and suggests areas for further research. Agomelatine is a synthetic analog of the hormone melatonin. It stimulates the activity of melatonin MT1 and MT2 receptors and inhibits the activity of serotonin 5HT-2C receptor subtypes. Three acute trials demonstrated clinically modest, but statistically significant benefits over placebo. Three acute trials did not find agomelatine more effective than placebo. A meta-analysis of these six trials demonstrated a small, statistically significant, marginally clinically relevant difference between agomelatine and placebo. The only placebo-controlled study in elderly patients did not demonstrate a significant benefit for agomelatine. It was more effective than placebo in only one of two relapse prevention studies. Agomelatine was generally well tolerated compared to placebo. Its side-effect profile is different than and compares favorably to other antidepressant drugs. The overall tolerability of agomelatine in head-to-head comparisons was not substantially better than active drug comparators. Agomelatine is contraindicated in patients with impaired liver function and in patients taking drugs that potently inhibit CYP-1A2 metabolic enzymes. Because elevated liver enzymes are common, and there is a rare risk of more serious liver reactions, routine laboratory monitoring of liver function is recommended periodically throughout treatment. Agomelatine does not have clinically significant advantages compared to other antidepressant drugs, and it has certain limitations and disadvantages. Because of its unique pharmacology and relatively benign tolerability profile, however, it may be a useful alternative for patients who do not respond to or cannot tolerate other antidepressant drugs.

Fluoxetine and olanzapine combination therapy in treatment-resistant major depression: review of efficacy and safety data

BACKGROUND

There has been growing evidence supporting the use of atypical antipsychotic drugs as adjunctive treatments in patients with major depression who fail to respond adequately to antidepressants.

OBJECTIVE

To review the efficacy and safety data for one such combination, fluoxetine (FLX) + olanzapine (OLZ) in treatment-resistant depression (TRD).

METHODS

We reviewed published randomized, controlled acute-phase studies, as well as available long-term clinical studies.

RESULTS/CONCLUSIONS

In each acute-phase study (n = 5), FLX/OLZ group experienced rapid antidepressant effects and, in two of these studies, resulted in significantly greater improvement at study end point compared with antidepressant monotherapy. These effects were strongest when TRD was defined as having failed at least two antidepressant trials during the current depressive episode. FLX + OLZ was generally well tolerated; however, increases in body weight and prolactin levels with FLX + OLZ were greater than that of antidepressant monotherapy groups and were similar to OLZ monotherapy. However, changes in random total cholesterol were also greatest for FLX + OLZ and were greater in magnitude than that of OLZ or FLX monotherapy. Long-term effectiveness/safety data are sparse, and comparison trials and sequential treatment studies involving FLX + OLZ and other antidepressant-atypical antipsychotic combinations are lacking. Thus, the exact place of FLX + OLZ among other available options for TRD is difficult to determine.

Medicating mood with maintenance in mind: bipolar depression pharmacotherapy

OBJECTIVES

Bipolar depression is a core feature of bipolar disorder, a phase in which many patients spend the majority of time and one that confers a significant degree of burden and risk. The purpose of this paper is to briefly review the evidence base for the pharmacotherapy of bipolar depression and to discuss the recommendations for its optimal management.

METHODS

A detailed literature review was undertaken with a particular emphasis on pharmacological treatment strategies for bipolar depression across the acute and maintenance phases of the illness. Electronic library and Web-based searches were performed using recognised tools (MEDLINE, PubMED, EMBASE and PsychINFO) to identify the pertinent literature. A summary of the evidence base is outlined and then distilled into broad clinical recommendations to guide the pharmacological management of bipolar depression.

RESULTS

Partitioning treatment into acute and maintenance therapy is difficult based on the paucity of current evidence. The evidence from treatment trials favours the use of lithium and lamotrigine as first-line treatment in preference to valproate, and indicates that, for acute episodes, quetiapine and olanzapine have perhaps achieved equivalence at least in terms of efficacy. However, the effectiveness of the atypical antipsychotics in maintenance therapy is constrained by the potential for significant side effects of individual agents and the lack of both long-term research data and clinical experience in treating bipolar disorder as compared to other agents. Conversely, lithium and the anticonvulsants are generally slower to effect symptomatic change, and this limits their usefulness.

CONCLUSIONS

There has been a tendency for research trials of bipolar depression to differentiate the illness cross-sectionally into the acute and maintenance phases of bipolar depression; however, in clinical terms, bipolar depression invariably follows a longitudinal course in which the phases of illness are inextricably linked, and useful acute treatments are typically continued in maintenance. Therefore, when medicating mood in acute bipolar depression it is imperative to keep maintenance in mind as it is this aspect of treatment that determines long-term success.

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

For over half a century, lithium has been the gold standard amongst the pharmacological armamentarium used to treat bipolar disorder. Its ascendancy in this regard has been attributed partly to its primacy of discovery and clinical implementation; however, it is important to consider how it has achieved success and retained its prominence and whether this is because of its unique profile and specificity of actions. In this paper, we briefly discuss the clinical evidence in support of lithium specificity and argue for its continuing use in those patients most likely to benefit, namely, patients with 'classic' bipolar disorder. Further, we suggest that accurate characterization of 'lithium responders' through focused research is likely to yield novel treatments and assist in better understanding of the pathophysiology of the illness. In addition, the unique antisuicidal actions of lithium warrant further examination, as do its impressive properties as a prophylactic agent. This is particularly so given the high morbidity associated with bipolar disorder and its potential for suicide. Hence, in this paper, after describing the changing diagnostic backdrop against which much of the research to date has been conducted, we discuss the clinical therapeutic profile of lithium in both the acute and long-term management of bipolar disorder and its phenotypic specificity of action. We demonstrate that lithium possesses significant clinical and therapeutic efficacy that is very individual and thus remains the treatment of choice for bipolar disorder when used specifically in select patients.

Evidence-based guidelines for treating bipolar disorder: revised second edition--recommendations from the British Association for Psychopharmacology

The British Association for Psychopharmacology guidelines specify the scope and target of treatment for bipolar disorder. The second version, like the first, is based explicitly on the available evidence and presented, like previous Clinical Practice guidelines, as recommendations to aid clinical decision making for practitioners: they may also serve as a source of information for patients and carers. The recommendations are presented together with a more detailed but selective qualitative review of the available evidence. A consensus meeting, involving experts in bipolar disorder and its treatment, reviewed key areas and considered the strength of evidence and clinical implications. The guidelines were drawn up after extensive feedback from participants and interested parties. The strength of supporting evidence was rated. The guidelines cover the diagnosis of bipolar disorder, clinical management, and strategies for the use of medicines in treatment of episodes, relapse prevention and stopping treatment.

Augmentation of antidepressants with perospirone for treatment-resistant major depressive disorder

We examined the efficacy and tolerability of perospirone, a dopamine D2 and 5-HT2A receptor antagonist and a partial 5-HT1A receptor agonist, in the augmentation of antidepressant treatment of partially responding and nonresponding patients with major depressive disorder. Twelve patients with major depressive disorder and an incomplete or no response to different kinds of antidepressants (selective serotonin reuptake inhibitor, milnacipran, or sulpride) monotherapy or polytherapy for 8 weeks or more were treated with perospirone augmentation in an eight-week, open-label study. Data were gathered from July 2006 to March 2008. The mean duration of antidepressant pharmacotherapy at baseline was 28 weeks. At baseline, the mean (+/-SD) of the MADRS scores was 35.8+/-10.1. The mean (+/-SD) initial dose of perospirone was 7.0+/-2.9 mg/day and the final dose was 11.7+/-6.6 mg/day. Significant reductions in MADRS scores were observed at weeks 2, 4, 6 and 8. Although two of the twelve subjects who completed the protocol achieved remission by the study endpoint, five of the twelve patients were responders (i.e., >50% improvement in the MADRS score). Sleepiness and tremor were observed in six patients and one patient, respectively, resulting in a reduction of perospirone dose due to these side effects. The discontinuation rate after 8 weeks of treatment was zero. These findings suggest that perospirone may be an effective augmentation strategy for improving therapeutic response in patients with treatment-resistant major depressive disorder when administered in combination with standard antidepressant therapy. Based on this clinical evidence, a double-blind, placebo-controlled trial is warranted.

Sexual dysfunction, depression, and the impact of antidepressants

Sexual dysfunction is a common symptom of depression. Although decreased libido is most often reported, difficulties with arousal, resulting in vaginal dryness in women and erectile dysfunction in men, and absent or delayed orgasm are also prevalent. Sexual dysfunction is also a frequent adverse effect of treatment with most antidepressants and is one of the predominant reasons for premature drug discontinuation. Selective serotonin reuptake inhibitors are the most widely prescribed antidepressants and have significant effects on arousal and orgasm compared with antidepressants that target norepinephrine, dopamine, and melatonin systems. The availability of an antidepressant that does not cause or exacerbate sexual dysfunction represents an advance in pharmacotherapy for mood disorders and should reduce treatment noncompliance and decrease the need for switching antidepressants or adding antidotes. The purpose of this review was to provide an update on the prevalence, psychobiology, and relative adverse effect burden of sexual dysfunction associated with different antidepressants.

Novel treatments for major depressive disorder

Data from a variety of studies, including the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study, have shown that fewer patients achieve remission from symptoms of major depressive disorder (MDD) and other depressive disorders after taking the first-prescribed antidepressant treatment than was expected. The goal of treatment is true remission: the complete absence of symptoms. Achieveing less than true remission is associated with MDD recurrence and continued impairment.

Pharmacologic and therapeutic strategies in treatment-resistant depression. Switching antidepressants vs. conventional augmentation strategies

Antidepressants have been available since the 1950s, when the monoamine oxidase inhibitors were first discovered. Since then, our armamentarium of antidepressants has progressively expanded with the discovery of the tricyclic antidepressants (TCAs) in the 1960s, the selective serotonin reuptake inhibitors (SSRIs) in the 1980s, and, subsequently, the serotonin norepinephrine reuptake inhibitors (SNRIs), and other agents possessing a diverse mechanism of action including buproprion, and mirtazapine.

Aripiprazole: in major depressive disorder

Aripiprazole, an oral quinolinone, is the first atypical antipsychotic agent to be approved in the US as adjunctive treatment in adult patients with major depressive disorder (MDD). In two large, well-designed trials in patients with MDD who had an inadequate response to standard antidepressant therapy, 6 weeks' adjunctive therapy with aripiprazole 2-20 mg/day improved mean Montgomery Asberg Depression Rating Scale (MADRS) total scores (primary endpoint) to a significantly greater extent than adjunctive placebo treatment. Improvements in mean MADRS total score during the double-blind phase favoured adjunctive aripiprazole treatment from 1-2 weeks onward, with per-protocol subgroup analyses showing that mean changes were not affected by the specific standard antidepressant therapy used, age or sex of the patient or the mean MADRS total scores at the start of double-blind adjunctive therapy. In general, secondary endpoint scores, including those for the Sheehan Disability Scale, Clinical Global Impression (CGI) Improvement scale and CGI Severity of Illness scale, improved to a significantly greater extent with adjunctive aripiprazole than with adjunctive placebo treatment, with significantly higher response and remission rates in the aripiprazole groups. In these two pivotal trials, adjunctive aripiprazole 2-20 mg/day was generally well tolerated, with most treatment-emergent adverse events being of mild to moderate severity.

Olanzapine and fluoxetine combination therapy for treatment-resistant depression: review of efficacy, safety, and study design issues

Treatment-resistant depression (TRD) is a common occurrence in clinical practice. Up to 30% of patients with major depression do not respond to conventional antidepressant treatment, while a significantly greater number of patients experience only partial symptom reduction. Numerous strategies may be applied by the practicing clinician to overcome limitations in the effectiveness of antidepressant monotherapy, including combining drug treatment with evidence-supported psychotherapies, combining antidepressants (combination pharmacotherapy), and combining antidepressants with other non-antidepressant psychotropic medications (augmentation treatment). One such augmentation strategy, the combination of the selective serotonin reuptake inhibitor, fluoxetine (FLX), with the atypical antipsychotic drug, olanzapine (OLZ), is supported by the results of four randomized, double-blind, acute phase studies of patients who had responded inadequately to antidepressant monotherapy. In each study, the FLX/OLZ combination caused rapid reduction in Montgomery-Asberg Depression Rating scale scores, with two of the four studies showing significantly greater improvement than antidepressant monotherapy at study endpoint. Effects of the FLX/OLZ combination were strongest in cases where failure to respond to two antidepressants prior to randomization was established during the current depressive episode. The FLX/OLZ combination was well-tolerated; however, body weight gain and increases in prolactin were greater than that of the antidepressant monotherapy groups, and were comparable to that of OLZ monotherapy. While effective during acute-phase treatment, questions remain regarding the long-term efficacy and safety of FLX/OLZ relative to antidepressant monotherapy and other combination strategies. Efforts aimed at determining the placement of FLX/OLZ among the available options for addressing TRD are limited by lack of comparison and sequential treatment studies. Important aspects of study design and directions for future research are discussed.

Augmentation strategies for treatment-resistant depression

PURPOSE OF REVIEW

The majority of patients with depression fail to remit on one or more antidepressant trials. These patients have treatment-resistant depression (TRD) with high relapsing rates. Augmentation pharmacotherapy refers to the addition of drugs that are not standard antidepressants in order to enhance the effect of a classical antidepressant drug. This review highlights the current status and future research directions of augmentation treatments for TRD with a special focus on research data published within the past year.

RECENT FINDINGS

Atypical antipsychotics, stimulants, pindolol, lithium, lamotrigine and mecamylamine were tested for efficacy in clinical trials. Most of the trials were not controlled or had limited sample size. Recent data now support the use of some atypical antipsychotics to augment depression resistant to the newer, more selective, antidepressants.

SUMMARY

Lithium and triiodothyronin (T3) augmentation of tricyclic agents remains the best studied strategy. Data converge to demonstrate the efficacy of some atypical antipsychotics as augmenting agents to selective serotonin reuptake inhibitors. Further adequately powered controlled trials on augmentation pharmacotherapy of TRD are necessary.

Elevated 5-HT 2A receptors in postmortem prefrontal cortex in major depression is associated with reduced activity of protein kinase A

Previous human postmortem brain tissue research has implicated abnormalities of 5-HT receptor availability in depression and suicide. Although altered abundance of 5-HT 1A, 5-HT 2A, and 5-HT 2C receptors (5-HT(1A), 5-HT(2A), and 5-HT(2C)) has been reported, the causes remain obscure. This study evaluated the availability of these three receptor subtypes in postmortem brain tissue specimens from persons with a history of major depression (MDD) and normal controls and tested the relationships to protein kinases A and C (PKA, PKC). Samples were obtained from postmortem brain tissue (Brodmann area 10) from 20 persons with a history of MDD and 20 matched controls as determined by a retrospective diagnostic evaluation obtained from family members. Levels of 5-HT(1A), 5-HT(2A), and 5-HT(2C) receptor were quantitated via Western blot analyses. Basal and stimulated PKA and PKC activity were also determined. The depressed samples showed significantly increased 5-HT(2A) receptor abundance relative to controls, but no differences in 5-HT(1A) or 5-HT(2C) receptors. Basal and cyclic AMP-stimulated PKA activity was also reduced in the depressed sample; PKC activity was not different between groups. 5-HT(2A) receptor availability was significantly inversely correlated with PKC activity in controls, but with PKA activity in the depressed sample. Increased 5-HT(2A) receptor abundance and decreased PKA activity in the depressed sample are consistent with prior reports. The correlation of 5-HT(2A) receptor levels with PKA activity in the depressed group suggests that abnormalities of 5-HT(2A) receptor abundance may depend on receptor uncoupling and heterologous regulation by PKA.

New developments in the management of major depressive disorder and generalized anxiety disorder: role of quetiapine

Quetiapine has demonstrated efficacy in schizophrenia, bipolar disorder and in the treatment of specific symptom clusters such as agitation and sleep problems in mood disorders. In this review, randomized controlled studies demonstrating efficacy, safety and tolerability of quetiapine in major depressive disorder (MDD) and general anxiety disorder (GAD) are evaluated. The results show that quetiapine monotherapy and quetiapine augmentation of antidepressant treatment in MDD and GAD are efficacious for short-term and maintenance treatment at a dose range between 50 and 300 mg/day. Quetiapine appears to have a specific but overall mild side-effect profile, though, some adverse effects such as sedation and somnolence may lead to withdrawal from treatment in some patients. Overall, the available evidence suggests that there is a significant role for quetiapine in the treatment of MDD and GAD.