Augmentation of antidepressants with atypical antipsychotics: a review of the current literature

Pharmacological Augmentation in Unipolar Depression: A Guide to the Guidelines

BACKGROUND

Pharmacological augmentation is a recommended strategy for patients with treatment-resistant depression. A range of guidelines provide advice on treatment selection, prescription, monitoring and discontinuation, but variation in the content and quality of guidelines may limit the provision of objective, evidence-based care. This is of importance given the side effect burden and poorer long-term outcomes associated with polypharmacy and treatment-resistant depression. This review provides a definitive overview of pharmacological augmentation recommendations by assessing the quality of guidelines for depression and comparing the recommendations made.

METHODS

A systematic literature search identified current treatment guidelines for depression published in English. Guidelines were quality assessed using the Appraisal of Guidelines for Research and Evaluation II tool. Data relating to the prescription of pharmacological augmenters were extracted from those developed with sufficient rigor, and the included recommendations compared.

RESULTS

Total of 1696 records were identified, 19 guidelines were assessed for quality, and 10 were included. Guidelines differed in their quality, the stage at which augmentation was recommended, the agents included, and the evidence base cited. Lithium and atypical antipsychotics were recommended by all 10, though the specific advice was not consistent. Of the 15 augmenters identified, no others were universally recommended.

CONCLUSIONS

This review provides a comprehensive overview of current pharmacological augmentation recommendations for major depression and will support clinicians in selecting appropriate treatment guidance. Although some variation can be accounted for by date of guideline publication, and limited evidence from clinical trials, there is a clear need for greater consistency across guidelines to ensure patients receive consistent evidence-based care.

The Care of Patients With Complex Mood Disorders

This article focuses on some common dilemmas facing clinicians, patients, and families in managing the treatment of complicated mood disorders. Specifically, this article reviews the interaction of depressive states, including unipolar, bipolar, and mixed, with other adversities, including comorbid physical and psychological disorders, personality vulnerabilities, misuse of drugs and alcohol, and social and family problems. These issues are not always clearly differentiated from the depressive illness. Each of these adversities can worsen an existing mood disorder and influence the patient's resolve to persist with a treatment plan. Although this article is not focused strictly on treatment-resistant depression, these coexisting issues make depressive states harder to manage therapeutically. For brevity, the aim of this article has been limited to discussion of some complex situations that psychiatrists in general practice may encounter.

Impact of Atypical Antipsychotics as Adjunctive Therapy on Psychiatric Cost and Utilization in Patients with Major Depressive Disorder

Introduction

Patients with major depressive disorder (MDD) incur high costs, despite established treatment options. Adding an atypical antipsychotic (AAP) to antidepressant therapy has shown to reduce depressive symptoms in MDD, but it remains unclear with which adjunctive AAP to initiate. As economic burden is one factor that can influence treatment selection, this study's objective was to evaluate the impact of adjunctive AAP choice on psychiatric costs and healthcare utilization in MDD.

Materials and Methods

This retrospective cohort study analyzed de-identified data from: (1) IBM^® MarketScan^® Commercial (C), Medicare Supplemental (MS), and MarketScan Multi-State Medicaid (M) Databases, and (2) Optum^® Clinformatics^® Datamart. Adult MDD patients were included if they had: initiated adjunctive AAPs during study identification period (7/1/15-9/30/16 MarketScan C/MS, and Optum; 7/1/15-6/30/16 MarketScan M), and ≥12 months of continuous enrollment before (baseline) and after (follow-up) first treatment date. Models included generalized linear models (GLMs) for psychiatric costs (total inpatient and outpatient services, excluding outpatient pharmacy costs), and a two-part model (logistic regression for psychiatric hospitalizations, GLM for psychiatric hospitalization costs among hospitalized patients); models were adjusted for baseline characteristics.

Results

The final study sample consisted of 10,325 patients (7657 aripiprazole, 1219 brexpiprazole, 827 lurasidone, 622 quetiapine). Using brexpiprazole as reference, lurasidone and quetiapine users had $1662 and $3894 higher psychiatric costs, respectively. Psychiatric costs were not statistically significantly different between aripiprazole and brexpiprazole (p>0.05). Quetiapine users had $15,159 (p<0.001) higher psychiatric hospitalization costs among those hospitalized, and higher odds of psychiatric hospitalization [2.11 (1.46-3.04); p<0.001] compared to brexpiprazole users. No statistically significant differences observed in psychiatric hospitalization risk comparing aripiprazole and lurasidone with brexpiprazole (p>0.05).

Conclusion

In MDD, brexpiprazole users had significantly lower psychiatric costs than lurasidone and quetiapine users, and significantly lower psychiatric hospitalization risk than quetiapine users. Adjunctive AAP choice may impact subsequent healthcare costs and utilization in MDD.

Depression

Major depression is a common illness that severely limits psychosocial functioning and diminishes quality of life. In 2008, WHO ranked major depression as the third cause of burden of disease worldwide and projected that the disease will rank first by 2030.¹ In practice, its detection, diagnosis, and management often pose challenges for clinicians because of its various presentations, unpredictable course and prognosis, and variable response to treatment.

Royal Australian and New Zealand College of Psychiatrists clinical practice guidelines for mood disorders

OBJECTIVES

To provide guidance for the management of mood disorders, based on scientific evidence supplemented by expert clinical consensus and formulate recommendations to maximise clinical salience and utility.

METHODS

Articles and information sourced from search engines including PubMed and EMBASE, MEDLINE, PsycINFO and Google Scholar were supplemented by literature known to the mood disorders committee (MDC) (e.g., books, book chapters and government reports) and from published depression and bipolar disorder guidelines. Information was reviewed and discussed by members of the MDC and findings were then formulated into consensus-based recommendations and clinical guidance. The guidelines were subjected to rigorous successive consultation and external review involving: expert and clinical advisors, the public, key stakeholders, professional bodies and specialist groups with interest in mood disorders.

RESULTS

The Royal Australian and New Zealand College of Psychiatrists clinical practice guidelines for mood disorders (Mood Disorders CPG) provide up-to-date guidance and advice regarding the management of mood disorders that is informed by evidence and clinical experience. The Mood Disorders CPG is intended for clinical use by psychiatrists, psychologists, physicians and others with an interest in mental health care.

CONCLUSIONS

The Mood Disorder CPG is the first Clinical Practice Guideline to address both depressive and bipolar disorders. It provides up-to-date recommendations and guidance within an evidence-based framework, supplemented by expert clinical consensus.

MOOD DISORDERS COMMITTEE

Professor Gin Malhi (Chair), Professor Darryl Bassett, Professor Philip Boyce, Professor Richard Bryant, Professor Paul Fitzgerald, Dr Kristina Fritz, Professor Malcolm Hopwood, Dr Bill Lyndon, Professor Roger Mulder, Professor Greg Murray, Professor Richard Porter and Associate Professor Ajeet Singh.

INTERNATIONAL EXPERT ADVISORS

Professor Carlo Altamura, Dr Francesco Colom, Professor Mark George, Professor Guy Goodwin, Professor Roger McIntyre, Dr Roger Ng, Professor John O'Brien, Professor Harold Sackeim, Professor Jan Scott, Dr Nobuhiro Sugiyama, Professor Eduard Vieta, Professor Lakshmi Yatham.

AUSTRALIAN AND NEW ZEALAND EXPERT ADVISORS

Professor Marie-Paule Austin, Professor Michael Berk, Dr Yulisha Byrow, Professor Helen Christensen, Dr Nick De Felice, A/Professor Seetal Dodd, A/Professor Megan Galbally, Dr Josh Geffen, Professor Philip Hazell, A/Professor David Horgan, A/Professor Felice Jacka, Professor Gordon Johnson, Professor Anthony Jorm, Dr Jon-Paul Khoo, Professor Jayashri Kulkarni, Dr Cameron Lacey, Dr Noeline Latt, Professor Florence Levy, A/Professor Andrew Lewis, Professor Colleen Loo, Dr Thomas Mayze, Dr Linton Meagher, Professor Philip Mitchell, Professor Daniel O'Connor, Dr Nick O'Connor, Dr Tim Outhred, Dr Mark Rowe, Dr Narelle Shadbolt, Dr Martien Snellen, Professor John Tiller, Dr Bill Watkins, Dr Raymond Wu.

Optimizing the Use of Aripiprazole Augmentation in the Treatment of Major Depressive Disorder: From Clinical Trials to Clinical Practice

Major depressive disorder (MDD) is a recurrent, chronic, and devastating disorder leading to serious impairment in functional capacity as well as increasing public health care costs. In the previous decade, switching therapy and dose adjustment of ongoing antidepressants was the most frequently chosen subsequent treatment option for MDD. However, such recommendations were not based on firmly proven efficacy data from well-designed, placebo-controlled, randomized clinical trials (RCTs) but on practical grounds and clinical reasoning. Aripiprazole augmentation has been dramatically increasing in clinical practice owing to its unique action mechanisms as well as proven efficacy and safety from adequately powered and well-controlled RCTs. Despite the increased use of aripiprazole in depression, limited clinical information and knowledge interfere with proper and efficient use of aripiprazole augmentation for MDD. The objective of the present review was to enhance clinicians' current understanding of aripiprazole augmentation and how to optimize the use of this therapy in the treatment of MDD.

A Meta-Analysis Comparing Open-Label versus Placebo-Controlled Clinical Trials for Aripiprazole Augmentation in the Treatment of Major Depressive Disorder: Lessons and Promises

OBJECTIVE

The present study is to provide whether open-label studies (OLS) may properly foresee the efficacy of randomized, placebo-controlled trials (RCTs) using OLSs and RCTs data for aripiprazole in the treatment of MDD, with the use of meta-analysis approach.

METHODS

A search of the studies used the key terms "depression and aripiprazole" from the databases of PubMed/PsychInfo from Jan 2005 through July 2013. The data were selected and verified for publication in English-based peer-reviewed journals based on rigorous inclusion criteria. Extracted data were delivered into and run by the Comprehensive Meta Analysis program v2.

RESULTS

The pooled SMDs for the primary efficacy measure was statistically significant, pointing out the significant reduction of depressive symptoms after aripiprazole augmentation (AA) to current antidepressant treatment in OLSs (pooled SMD=-2.114, z=-9.625, p<0.001); similar results were also found in RCTs (pooled SMD=-2.202, z=-6.862, p<0.001). The meta-regression analysis revealed no influence of the study design for treatment outcome.

CONCLUSION

There was no difference in the treatment effects of aripiprazole as an augmentation therapy in both OLSs and RCTs, indicating that open-label design may be a potentially useful predictor for treatment outcomes of controlled-clinical trials. The proper conduction of OLSs may provide informative, useful and preliminary clinical data and factors to be involved in controlled-clinical trials, by which we may have better understanding on the role of AA (e.g., dosing issues, proper duration of treatment, specific population for AA) implicated in the treatment of MDD in clinical practice.

Fluoxetine-induced pancreatic beta cell dysfunction: New insight into the benefits of folic acid in the treatment of depression

BACKGROUND

Major depressive disorder is a common psychiatric illness with reported prevalence rates of 12-16% in persons aged 12 and over. Depression is also associated with a high risk of new onset of type 2 diabetes (T2D). This relationship between depression and diabetes may be related to depression itself and/or drugs prescribed. Importantly, the use of selective serotonin reuptake inhibitors (SSRIs), the most commonly prescribed class of antidepressants, increases the risk of developing T2D. However, the mechanism(s) underlying this association remains elusive.

METHODS

Here we examine the effects of the SSRI fluoxetine (Prozac®) on beta cell function utilizing INS-1E cells, a rat beta cell line, to elucidate the underlying molecular mechanisms.

RESULTS

Fluoxetine treatment significantly reduced glucose stimulated insulin secretion (GSIS). This decreased beta cell function was concomitant with an increased production of reactive oxygen species and oxidative damage which may contribute to decreased mitochondrial electron transport chain enzyme (ETC) activity. Importantly the fluoxetine-induced deficits in beta cell function were prevented by the addition of the antioxidant folic acid.

LIMITATIONS

These studies were conducted in vitro; the in vivo relevance remains to be determined.

CONCLUSIONS

These findings suggest that use of SSRI antidepressants may increase the risk of new-onset T2D by causing oxidative stress in pancreatic beta cells. However, folic acid supplementation in patients taking SSRIs may reduce the risk of new onset diabetes via protection of normal beta cell function.

Faster, better, stronger: towards new antidepressant therapeutic strategies

Major depression is a highly prevalent disorder and is predicted to be the second leading cause of disease burden by 2020. Although many antidepressant drugs are currently available, they are far from optimal. Approximately 50% of patients do not respond to initial first line antidepressant treatment, while approximately one third fail to achieve remission following several pharmacological interventions. Furthermore, several weeks or months of treatment are often required before clinical improvement, if any, is reported. Moreover, most of the commonly used antidepressants have been primarily designed to increase synaptic availability of serotonin and/or noradrenaline and although they are of therapeutic benefit to many patients, it is clear that other therapeutic targets are required if we are going to improve the response and remission rates. It is clear that more effective, rapid-acting antidepressants with novel mechanisms of action are required. The purpose of this review is to outline the current strategies that are being taken in both preclinical and clinical settings for identifying superior antidepressant drugs. The realisation that ketamine has rapid antidepressant-like effects in treatment resistant patients has reenergised the field. Further, developing an understanding of the mechanisms underlying the rapid antidepressant effects in treatment-resistant patients by drugs such as ketamine may uncover novel therapeutic targets that can be exploited to meet the Olympian challenge of developing faster, better and stronger antidepressant drugs.

The effect of prolonged exposure to morphine on canine cerebral 5-HT2A receptors measured with (123)I-R91150 SPECT

Down-stream neuronal alterations, including changes in the 5-HT-2A receptor system, play an important role in the etiology and treatment of depression. The present study examined the effect of prolonged opioid treatment on cerebral 5-HT2A receptors. Cerebral 5-HT2A receptor availability was estimated in seven healthy five-year-old female neutered Beagle dogs pre and post 10-day morphine treatment (oral sustained release morphine 20mg twice daily for 10 days) with (123)I-R-91150, a 5-HT2A selective radioligand, and SPECT. 5-HT2A receptor binding indices (BI) for the frontal, parietal, temporal and occipital cortex and the subcortical region were calculated. Statistical analysis was performed using a linear mixed-effect model with treatment as fixed effect and dog as random effect. Morphine treatment significantly (P≤0.05) lowered 5-HT2A BIs in the right and left frontal cortex, the right and left temporal cortex, the right and left parietal cortex, and the subcortical region. The decreased cerebral 5-HT2A receptor availability following prolonged morphine exposure provides further evidence for an interaction between the opioid and serotonergic system.

Effects of escitalopram/quetiapine combination therapy versus escitalopram monotherapy on hypothalamic-pituitary-adrenal-axis activity in relation to antidepressant effectiveness

The hypothalamic-pituitary-adrenocortical (HPA) system is believed to play an important role in the pathophysiology of major depressive disorder. In this context, the atypical antipsychotic quetiapine (QUE) has been shown to inhibit HPA system activity in healthy subjects. In this study we investigated whether the putative inhibitory effects of QUE on HPA system activity may contribute to its antidepressant efficacy. We analyzed the effects of QUE as an augmentation to the selective serotonin reuptake inhibitor (SSRI) escitalopram (ESC) on HPA system activity in comparison to a monotherapy with ESC in relation to the antidepressant effectiveness. HPA axis activity (cortisol and ACTH) was measured by means of the dexamethasone/corticotropin-releasing hormone (DEX/CRH) test which was performed before (week 0) and during (week 1, week 5) antidepressant psychopharmacotherapy. The combination therapy, but not the ESC monotherapy showed significantly inhibiting effects on HPA system activity leading to stepwise down-regulation. ACTH concentrations were reduced in the ESC/QUE group during five weeks of treatment. The inhibitory effect of QUE maybe involved in its antidepressant effects as an augmentation strategy.

Pharmacological management of unipolar depression

OBJECTIVE

To be used in conjunction with 'Psychological management of unipolar depression' [Lampe et al. Acta Psychiatr Scand 2013;127(Suppl. 443):24-37] and 'Lifestyle management of unipolar depression' [Berk et al. Acta Psychiatr Scand 2013;127(Suppl. 443):38-54]. To provide clinically relevant recommendations for the use of pharmacological treatments in depression derived from a literature review.

METHOD

Using our previous Clinical Practice Guidelines [Malhi et al. Clinical practice recommendations for bipolar disorder. Acta Psychiatr Scand 2009;119(Suppl. 439):27-46] as a foundation, these clinician guidelines target key practical considerations when prescribing pharmacotherapy. A comprehensive review of the literature was conducted using electronic database searches (PubMed, MEDLINE), and the findings have been synthesized and integrated alongside clinical experience.

RESULTS

The pharmacotherapy of depression is an iterative process that often results in partial and non-response. Beyond the initiation of antidepressants, the options within widely used strategies, such as combining agents and switching between agents, are difficult to prescribe because of the paucity of pertinent research. However, there is some evidence for second-line strategies, and a non-prescriptive algorithm can be derived that is based broadly on principles rather than specific steps.

CONCLUSION

Depression is by its very nature a heterogeneous illness that is consequently difficult to treat. Invariably, situation-specific factors often play a significant role and must be considered, especially in the case of partial and non-response. Consulting with colleagues and trialling alternate treatment paradigms are essential strategies in the management of depression.

Aripiprazole: a dopamine modulator that mimics methylphenidate in producing faster antidepressant effects

Up to 60% of depressed patients do not respond to two months of pharmacotherapy, and late treatment responses are often correlated with poor outcomes and may be characterized as treatment-resistant depression (TRD). Previous studies have noted that the addition of a psychostimulant such as methylphenidate to the therapeutic regimen of patients with TRD or those depressed patients with comorbid fatigue, advanced age, or a major medical illness showed significant improvement within two weeks. One explanation for the benefit of methylphenidate in treating TRD is that it enhances the level of dopamine in the brain. Adjunctive low dose aripiprazole in patients with TRD has also become a common intervention. Several studies have focused on aripiprazole's pharmacodynamic and pharmacokinetic profiles, but no definitive comments on its antidepressant effects. We hypothesize that a low dose of aripiprazole might play a role as a dopamine agonist similar to that of methylphenidate due to its partial dopamine D2 agonist and 30% intrinsic dopaminergic activity. In addition to its use in patients with TRD, adjunctive aripiprazole might work like methylphenidate in those depressed patients with fatigue, advanced age, or major illnesses. A new drug invention which combined an antidepressant with an adequate dose of aripiprazole should be considered. The neurobiological basis for this combination in treating TRD awaits further study.

Clinical issues in use of atypical antipsychotics for depressed patients

Major depressive disorder (MDD) is a chronic, recurrent mental disease that causes serious disability. Because currently available antidepressants have limited efficacy with respect to response and remission in patients with MDD, clinicians must choose the best available treatment interventions for patients who do not respond to initial antidepressant treatment. The existing literature demonstrates that augmentation with atypical antipsychotics (AAs) shows higher response and remission rates compared with antidepressant monotherapy, but is associated with more withdrawals due to adverse events. In this paper, specific clinical issues in the use of AA augmentation for patients with MDD are briefly discussed. Given the limited information and clinical knowledge on the proper and effective use of AAs for MDD, future research should focus on practical clinical issues that can be commonly seen in routine practice but have not been addressed yet. This is because the use of AAs is likely to expand as there is good evidence for their effectiveness and tolerability as augmentation therapy for patients with MDD.

Effect of atypical antipsychotics on fetal growth: is the placenta involved?

There is currently considerable uncertainty regarding prescribing practices for pregnant women with severe and persistent psychiatric disorders. The physician and the mother have to balance the risks of untreated psychiatric illness against the potential fetal toxicity associated with pharmacological exposure. This is especially true for women taking atypical antipsychotics. Although these drugs have limited evidence for teratological risk, there are reports of altered fetal growth, both increased and decreased, with maternal atypical antipsychotic use. These effects may be mediated through changes in the maternal metabolism which in turn impacts placental function. However, the presence of receptors targeted by atypical antipsychotics in cell lineages present in the placenta suggests that these drugs can also have direct effects on placental function and development. The signaling pathways involved in linking the effects of atypical antipsychotics to placental dysfunction, ultimately resulting in altered fetal growth, remain elusive. This paper focuses on some possible pathways which may link atypical antipsychotics to placental dysfunction.

Increase of antipsychotic medication in depressive inpatients from 2000 to 2007: results from the AMSP International Pharmacovigilance Program

While international guidelines recommend monotherapy with antidepressants for depressed patients, recent investigation has demonstrated augmenting effects of antipsychotics (APs) in patients with major depression. We set out to investigate the use of APs in a European sample of depressed inpatients and the possible changes in their prescription over the period from 2000 to 2007. On two reference days in the years 2000 (32 psychiatric institutions, N=1078) and 2007 (54 psychiatric institutions, N=1826), the following data were recorded for all depressed inpatients (ICD-10: F32.00, F32.01, F32.1, F32.10, F32.11, F32.2, F33.0, F33.00, F33.01, F33.1, F33.10, F33.11, F33.2), monitored as part of the AMSP (Arzneimittelsicherheit in der Psychiatrie) surveillance programme: age, sex, ICD-10 diagnosis and all medication applied on that day. Depressed inpatients with psychotic symptoms were excluded. We found a significant increase in the number of AP-treated inpatients from 37.9% in 2000 to 45.8% in 2007 (χ²=17.257, p<0.001). The number of inpatients who received an atypical AP rose significantly between 2000 and 2007, from 12.8% to 28.3% (χ²=93.37, p<0.001). On the contrary, the percentage of inpatients receiving typical APs showed a significant decrease from 30.2% to 24.1% over the same period (χ²=13.179, p<0.001). Examining only the subgroup of severely depressed inpatients we found an increase in the number of AP-treated inpatients, but this was not statistically significant (χ²=2.047, p=0.15). Our study revealed a significant increase in the usage of atypical APs. However, this effect was not only due to augmentation strategies for severely depressed inpatients. Further studies are needed to examine possible putative effects of AP augmentation treatment in mild to moderate depression.

Treatment-resistant depression: therapeutic trends, challenges, and future directions

BACKGROUND

Patients with major depression respond to antidepressant treatment, but 10%-30% of them do not improve or show a partial response coupled with functional impairment, poor quality of life, suicide ideation and attempts, self-injurious behavior, and a high relapse rate. The aim of this paper is to review the therapeutic options for treating resistant major depressive disorder, as well as evaluating further therapeutic options.

METHODS

In addition to Google Scholar and Quertle searches, a PubMed search using key words was conducted, and relevant articles published in English peer-reviewed journals (1990-2011) were retrieved. Only those papers that directly addressed treatment options for treatment-resistant depression were retained for extensive review.

RESULTS

Treatment-resistant depression, a complex clinical problem caused by multiple risk factors, is targeted by integrated therapeutic strategies, which include optimization of medications, a combination of antidepressants, switching of antidepressants, and augmentation with non-antidepressants, psychosocial and cultural therapies, and somatic therapies including electroconvulsive therapy, repetitive transcranial magnetic stimulation, magnetic seizure therapy, deep brain stimulation, transcranial direct current stimulation, and vagus nerve stimulation. As a corollary, more than a third of patients with treatment-resistant depression tend to achieve remission and the rest continue to suffer from residual symptoms. The latter group of patients needs further study to identify the most effective therapeutic modalities. Newer biomarker-based antidepressants and other drugs, together with non-drug strategies, are on the horizon to address further the multiple complex issues of treatment-resistant depression.

CONCLUSION

Treatment-resistant depression continues to challenge mental health care providers, and further relevant research involving newer drugs is warranted to improve the quality of life of patients with the disorder.

Glycogen Synthase Kinase-3 is an Intermediate Modulator of Serotonin Neurotransmission

Serotonin is a neurotransmitter with broad functions in brain development, neuronal activity, and behaviors; and serotonin is the prominent drug target in several major neuropsychiatric diseases. The multiple actions of serotonin are mediated by diverse serotonin receptor subtypes and associated signaling pathways. However, the key signaling components that mediate specific function of serotonin neurotransmission have not been fully identified. This review will provide evidence from biochemical, pharmacological, and animal behavioral studies showing that serotonin regulates the activation states of brain glycogen synthase kinase-3 (GSK3) via type 1 and type 2 serotonin receptors. In return, GSK3 directly interacts with serotonin receptors in a highly selective manner, with a prominent effect on modulating serotonin 1B receptor activity. Therefore, GSK3 acts as an intermediate modulator in the serotonin neurotransmission system, and balanced GSK3 activity is essential for serotonin-regulated brain function and behaviors. Particularly important, several classes of serotonin-modulating drugs, such as antidepressants and atypical antipsychotics, regulate GSK3 by inhibiting its activity in brain, which reinforces the importance of GSK3 as a potential therapeutic target in neuropsychiatric diseases associated with abnormal serotonin function.

Prenatal Cocaine Disrupts Serotonin Signaling-Dependent Behaviors: Implications for Sex Differences, Early Stress and Prenatal SSRI Exposure

Prenatal cocaine (PC) exposure negatively impacts the developing nervous system, including numerous changes in serotonergic signaling. Cocaine, a competitive antagonist of the serotonin transporter, similar to selective serotonin reuptake inhibitors (SSRIs), also blocks dopamine and norepinephrine transporters, leaving the direct mechanism through which cocaine disrupts the developing serotonin system unclear. In order to understand the role of the serotonin transporter in cocaine's effect on the serotonergic system, we compare reports concerning PC and prenatal antidepressant exposure and conclude that PC exposure affects many facets of serotonergic signaling (serotonin levels, receptors, transporters) and that these effects differ significantly from what is observed following prenatal SSRI exposure. Alterations in serotonergic signaling are dependent on timing of exposure, test regimens, and sex. Following PC exposure, behavioral disturbances are observed in attention, emotional behavior and stress response, aggression, social behavior, communication, and like changes in serotonergic signaling, these effects depend on sex, age and developmental exposure. Vulnerability to the effects of PC exposure can be mediated by several factors, including allelic variance in serotonergic signaling genes, being male (although fewer studies have investigated female offspring), and experiencing the adverse early environments that are commonly coincident with maternal drug use. Early environmental stress results in disruptions in serotonergic signaling analogous to those observed with PC exposure and these may interact to produce greater behavioral effects observed in children of drug-abusing mothers. We conclude that based on past evidence, future studies should put a greater emphasis on including females and monitoring environmental factors when studying the impact of PC exposure.

A review of treating depression in diabetes: emerging findings

BACKGROUND

Depression in patients with diabetes is associated with poorer adherence and worse health outcomes, however treating depression may help improve these outcomes.

OBJECTIVE

The present systematic review identified published papers to evaluate treatments for depression in patients with diabetes.

RESULTS

Seventeen studies that met criteria were identified, indicating that psychosocial interventions, particularly cognitive-behavior therapy, anti-depressant medications, and collaborative care are effective in the treatment of depression in patients with diabetes.

CONCLUSION

Evidence for the efficacy of these interventions in improving glycemic control was mixed. No study targeted adherence to treatment or health behaviors in addition to depression, which may be necessary to maximize improvement in diabetes outcomes such as glycemic control.

Aripiprazole in anorexia nervosa and low-weight bulimia nervosa: case reports

OBJECTIVE

There has been much interest in the use of atypical antipsychotics in anorexia nervosa (AN). However, newer, more weight-neutral medications have not been studied in AN, and there are no reports of the use of antipsychotics in bulimia nervosa (BN).

METHOD

We report on the treatment of eight patients (five with AN and three with BN) with aripiprazole for time periods of four months to more than three years.

RESULTS

All individuals had reduced distress around eating, fewer obsessional thoughts about food, weight and body image, significant lessening of eating-disordered behaviors, and gradual weight restoration where appropriate. Depression, generalized anxiety, and cognitive flexibility improved as well.

DISCUSSION

In summary, these findings support the need to perform controlled trials of aripiprazole in AN and BN.

The role of serotonin receptor subtypes in treating depression: a review of animal studies

RATIONALE

Serotonin reuptake inhibitors (SSRIs) are effective in treating depression. Given the existence of different families and subtypes of 5-HT receptors, multiple 5-HT receptors may be involved in the antidepressant-like behavioral effects of SSRIs.

OBJECTIVE

Behavioral pharmacology studies investigating the role of 5-HT receptor subtypes in producing or blocking the effects of SSRIs were reviewed.

RESULTS

Few animal behavior tests were available to support the original development of SSRIs. Since their development, a number of behavioral tests and models of depression have been developed that are sensitive to the effects of SSRIs, as well as to other types of antidepressant treatments. The rationale for the development and use of these tests is reviewed. Behavioral effects similar to those of SSRIs (antidepressant-like) have been produced by agonists at 5-HT(1A), 5-HT(1B), 5-HT(2C), 5-HT(4), and 5-HT(6) receptors. Also, antagonists at 5-HT(2A), 5-HT(2C), 5-HT(3), 5-HT(6), and 5-HT(7) receptors have been reported to produce antidepressant-like responses. Although it seems paradoxical that both agonists and antagonists at particular 5-HT receptors can produce antidepressant-like effects, they probably involve diverse neurochemical mechanisms. The behavioral effects of SSRIs and other antidepressants may also be augmented when 5-HT receptor agonists or antagonists are given in combination.

CONCLUSIONS

The involvement of 5-HT receptors in the antidepressant-like effects of SSRIs is complex and involves the orchestration of stimulation and blockade at different 5-HT receptor subtypes. Individual 5-HT receptors provide opportunities for the development of a newer generation of antidepressants that may be more beneficial and effective than SSRIs.

Is glycogen synthase kinase-3 a central modulator in mood regulation?

Little is known regarding the mechanisms underlying the complex etiology of mood disorders, represented mainly by major depressive disorder and bipolar disorder. The 1996 discovery that lithium inhibits glycogen synthase kinase-3 (GSK3) raised the possibility that impaired inhibition of GSK3 is associated with mood disorders. This is now supported by evidence from animal biochemical, pharmacological, molecular, and behavioral studies and from human post-mortem brain, peripheral tissue, and genetic studies that are reviewed here. Mood disorders may result in part from impairments in mechanisms controlling the activity of GSK3 or GSK3-regulated functions, and disruptions of these regulating systems at different signaling sites may contribute to the heterogeneity of mood disorders. This substantial evidence supports the conclusion that bolstering the inhibitory control of GSK3 is an important component of the therapeutic actions of drugs used to treat mood disorders and that GSK3 is a valid target for developing new therapeutic interventions.

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.

Aripiprazole as adjunct to a mood stabilizer and citalopram in bipolar depression: a randomized placebo-controlled pilot study

OBJECTIVE

The use of atypical antipsychotics (AAPs) for the treatment of unipolar and bipolar depression has been more and more frequently evaluated, and aripiprazole showed positive effects in the treatment of unipolar depression. However, no placebo-controlled studies of adjunctive aripiprazole for the treatment of bipolar depression have been performed yet.

METHODS

In this prospective, double-blind, placebo-controlled, randomized trial, 23 inpatients with bipolar depression according to DSM-IV criteria were included. Before randomization, patients had to be on a constant mood stabilizer treatment with lithium or valproate for at least 1 week. After inclusion, all patients were openly treated with additional citalopram and with additional aripiprazole or placebo for 6 weeks. The primary outcome parameter was the reduction in depressive symptoms according to the Hamilton Depression Rating Scale (HDRS) within 6 weeks.

RESULTS

After 6 weeks of treatment, the HDRS score decreased in both groups. There was no significant difference between both the groups at any point of time with respect to the HDRS.

CONCLUSIONS

Derived from this small pilot study, adjunctive aripiprazole does not seem to be a promising strategy for the acute treatment of bipolar depression. However, this lack of additional benefit seems to stem from the already good effectiveness of the control group, namely the treatment with citalopram.

Therapeutic options for treatment-resistant depression

Treatment-resistant depression (TRD) presents major challenges for both patients and clinicians. There is no universally accepted definition of TRD, but results from the US National Institute of Mental Health's (NIMH) STAR*D (Sequenced Treatment Alternatives to Relieve Depression) programme indicate that after the failure of two treatment trials, the chances of remission decrease significantly. Several pharmacological and nonpharmacological treatments for TRD may be considered when optimized (adequate dose and duration) therapy has not produced a successful outcome and a patient is classified as resistant to treatment. Nonpharmacological strategies include psychotherapy (often in conjunction with pharmacotherapy), electroconvulsive therapy and vagus nerve stimulation. The US FDA recently approved vagus nerve stimulation as adjunctive therapy (after four prior treatment failures); however, its benefits are seen only after prolonged (up to 1 year) use. Other nonpharmacological options, such as repetitive transcranial stimulation, deep brain stimulation or psychosurgery, remain experimental and are not widely available. Pharmacological treatments of TRD can be grouped in two main categories: 'switching' or 'combining'. In the first, treatment is switched within and between classes of compounds. The benefits of switching include avoidance of polypharmacy, a narrower range of treatment-emergent adverse events and lower costs. An inherent disadvantage of any switching strategy is that partial treatment responses resulting from the initial treatment might be lost by its discontinuation in favour of another medication trial. Monotherapy switches have also been shown to have limited effectiveness in achieving remission. The advantage of combination strategies is the potential to build upon achieved improvements; they are generally recommended if partial response was achieved with the current treatment trial. Various non-antidepressant augmenting agents, such as lithium and thyroid hormones, are well studied, although not commonly used. There is also evidence of efficacy and increasing use of atypical antipsychotics in combination with antidepressants, for example, olanzapine in combination with fluoxetine (OFC) or augmentation with aripiprazole. The disadvantages of a combination strategy include multiple medications, a broader range of treatment-emergent adverse events and higher costs. Several experimental pharmaceutical treatment alternatives for TRD are also being explored in combination with antidepressants or as monotherapy. These less studied alternative compounds include pindolol, inositol, CNS stimulants, hormones, herbal supplements, omega-3 fatty acids, S-adenosyl-L-methionine, folic acid, lamotrigine, modafinil, riluzole and topiramate. In summary, despite an increasing variety of choices for the treatment of TRD, this condition remains universally undefined and represents an area of unmet medical need. There are few known approved pharmacological agents for TRD (aripiprazole and OFC) and overall outcomes remain poor. This might be an indication that depression itself is a heterogeneous condition with a great diversity of pathologies, highlighting the need for careful evaluation of individuals with depressive symptoms who are unresponsive to treatment. Clearly, more research is needed to provide clinicians with better guidance in making those treatment decisions--especially in light of accumulating evidence that the longer patients are unsuccessfully treated, the worse their long-term prognosis tends to be.

Augmentation effect of combination therapy of aripiprazole and antidepressants on forced swimming test in mice

RATIONALE

A deficiency in brain monoamine systems (serotonin, dopamine, and/or norepinephrine) have long been hypothesized for the pathogenesis of depression. Drugs enhancing neurotransmission of those monoamines have been proven to have antidepressant effects. We hypothesized that aripiprazole, a partial D(2) agonist, could increase the activity of various antidepressants in the mice forced swimming test (FST), an animal model of depression.

OBJECTIVES

The scope of this study was to investigate the antidepressant-like effect of aripiprazole, when combined with conventional antidepressants drugs.

MATERIALS AND METHODS

This study assessed the effects of co-administration of aripiprazole with selective serotonin reuptake inhibitors (SSRIs; sertraline, paroxetine, and citalopram), selective serotonin-norepinephrine reuptake inhibitors (SNRIs; venlafaxine and minalcipran), selective norepinephrine reuptake inhibitor (NRI; desipramine), and the dual dopamine and norepinephrine reuptake inhibitor (bupropion), using the FST in mice. Subactive doses of aripiprazole and antidepressants sertraline, paroxetine, citalopram, venlafaxine, minalcipran, bupropion (4 and 8 mg/kg), and desipramine (2 and 4 mg/kg) were given i.p. 30 and 45 min, respectively, before the test.

RESULTS

Aripiprazole (0.03 and 0.06 mg/kg) combined with inactive doses of antidepressants, increased the activity of all antidepressants with the exception of bupropion and desipramine.

CONCLUSION

The augmentation effects of aripiprazole, in the present study, are in agreement with clinical evidence suggesting that aripiprazole may enhance the efficacy of therapeutic effect of SSRIs and SNRIs but not of NRI. These results suggest that augmentation effect of aripiprazole only appears when 5-HT system is activated and might implicate complex regulation between dopamine and 5-HT(1A) and 5-HT(2A) receptors.

Effects of olanzapine and quetiapine on corticotropin-releasing hormone release in the rat brain

An altered regulation of the corticotropin-releasing hormone (CRH) system in the CNS is consistently associated with anxiety and depression; several drugs used to treat CNS disorders modulate--usually in a negative manner--CRH turnover in the brain, and it can be postulated that their effectiveness may be at least in part related to their effects on CRH. This study was aimed to investigate the effects of two atypical antipsychotics also employed in the treatment of bipolar disorders, i.e. quetiapine (QTP) and olanzapine (OLZ), on CRH release from isolated rat brain regions. Acute rat hypothalamic and hippocampal explants were exposed for 1 h to plain medium or medium containing the test drugs, either under baseline conditions or after stimulation of CRH release by veratridine or 56 mM KCl. CRH immunoreactivity present in the incubation medium and in the tissues was assessed by radioimmunoassay. QTP 10 microM but not OLZ inhibited baseline CRH secretion from the hypothalamus; neither drug affected basal CRH release from the hippocampus. Both QTP and OLZ, 1 and 10 microM, inhibited veratridine- or K(+)-stimulated CRH release from the hypothalamus, whereas OLZ only, when given at 10 microM, was able to inhibit stimulated CRH release from the hippocampus. In conclusion, two widely used atypical antipsychotics, QTP and OLZ are able to acutely reduce the release of CRH from isolated rat hypothalami and hippocampi.

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.

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.

Initial effectiveness, partial remission, and full remission in depression: focus on long-term treatment with SNRIs

Full remission, defined as the absence of all significant symptoms of depression over at least 6 months, is the ultimate goal of antidepressant therapy. Remission takes time and studies have shown that remission rates continue to rise for at least 3 months after initial improvement. Depression is a recurrent condition with a cumulative probability of recurrence of 40% over 2 years and 70% over 5 years after the first depressive episode. In addition the risk of recurrence increases with each new depressive episode. Continuing antidepressant treatment beyond the acute response significantly decreases the risk of recurrence. A double-blind study with the serotonin norepinephrine reuptake inhibitor milnacipran, for example, has shown that patients in remission following treatment with milnacipran who continued the active treatment for a further 12 months had significantly less relapse (P<.05) than those switched to placebo. In spite of the importance of maintaining antidepressant therapy, many patients do not continue treatment. Among the principal reasons for this are side effects and worries of psychological or physical dependence. To reduce the risk of relapse, treatment with effective, well-tolerated antidepressants with few withdrawal effects should be pursued for at least 6 months and possibly longer in patients already experiencing relapse.