Does the presence of accompanying symptom clusters differentiate the comparative effectiveness of second-line medication strategies for treating depression?

Different depression: motivational anhedonia governs antidepressant efficacy in Huntington's disease

Depression is more common in neurodegenerative diseases such as Huntington's disease than the general population. Antidepressant efficacy is well-established for depression within the general population: a recent meta-analysis showed serotonin norepinephrine reuptake inhibitors, tricyclic antidepressants and mirtazapine outperformed other antidepressants. Despite the severe morbidity, antidepressant choice in Huntington's disease is based on Class IV evidence. We used complementary approaches to determine treatment choice for depression in Huntington's disease: propensity score analyses of antidepressant treatment outcome using the ENROLL-HD data set, and a dissection of the cognitive mechanisms underlying depression in Huntington's disease using a cognitive battery based on the Research Domain Criteria for Depression. Study 1 included ENROLL-HD 5486 gene-positive adult patients started on an antidepressant medication for depression. Our outcome measures were depression (Hospital Anxiety and Depression Scale or Problem Behaviours Assessment 'Depressed Mood' item) at first follow-up (primary outcome) and all follow-ups (secondary outcome). The intervention was antidepressant class. We used Svyglm&Twang in R to perform propensity scoring, using known variables (disease progression, medical comorbidity, psychiatric morbidity, sedatives, number of antidepressants, demographics and antidepressant contraindications) to determine the probability of receiving different antidepressants (propensity score) and then included the propensity score in a model of treatment efficacy. Study 2 recruited 51 gene-positive adult patients and 26 controls from the South Wales Huntington's Disease Management Service. Participants completed a motor assessment, in addition to measures of depression and apathy, followed by tasks measuring consummatory anhedonia, motivational anhedonia, learning from reward and punishment and reaction to negative outcome. We used generalised linear models to determine the association between task performance and depression scores. Study 1 showed selective serotonin reuptake inhibitors outperformed serotonin norepinephrine reuptake inhibitors on the primary outcome (P = 0.048), whilst both selective serotonin reuptake inhibitors (P = 0.00069) and bupropion (P = 0.0045) were superior to serotonin norepinephrine reuptake inhibitors on the secondary outcome. Study 2 demonstrated an association between depression score and effort for reward that was not explained by apathy. No other mechanisms were associated with depression score. We found that selective serotonin reuptake inhibitors and bupropion outperform serotonin norepinephrine reuptake inhibitors at alleviating depression in Huntington's disease. Moreover, motivational anhedonia appears the most significant mechanism underlying depression in Huntington's disease. Bupropion is improves motivational anhedonia and has a synergistic effect with selective serotonin reuptake inhibitors. This work provides the first large-scale, objective evidence to determine treatment choice for depression in Huntington's disease, and provides a model for determining antidepressant efficacy in other neurodegenerative diseases.

Obligatory roles of dopamine D1 receptors in the dentate gyrus in antidepressant actions of a selective serotonin reuptake inhibitor, fluoxetine

Depression is a leading cause of disability. Current pharmacological treatment of depression is insufficient, and development of improved treatments especially for treatment-resistant depression is desired. Understanding the neurobiology of antidepressant actions may lead to development of improved therapeutic approaches. Here, we demonstrate that dopamine D1 receptors in the dentate gyrus act as a pivotal mediator of antidepressant actions in mice. Chronic administration of a selective serotonin reuptake inhibitor (SSRI), fluoxetine, increases D1 receptor expression in mature granule cells in the dentate gyrus. The increased D1 receptor signaling, in turn, contributes to the actions of chronic fluoxetine treatment, such as suppression of acute stress-evoked serotonin release, stimulation of adult neurogenesis and behavioral improvement. Importantly, under severely stressed conditions, chronic administration of a D1 receptor agonist in conjunction with fluoxetine restores the efficacy of fluoxetine actions on D1 receptor expression and behavioral responses. Thus, our results suggest that stimulation of D1 receptors in the dentate gyrus is a potential adjunctive approach to improve therapeutic efficacy of SSRI antidepressants.

Anatomo-Physiologic Basis for Auricular Stimulation

Introduction: Stimulation of cranial nerves modulates central nervous system (CNS) activity via the extensive connections of their brainstem nuclei to higher-order structures. Clinical experience with vagus-nerve stimulation (VNS) demonstrates that it produces robust therapeutic effects, however, posing concerns related to its invasiveness and side-effects. Discussion: Trigeminal nerve stimulation (TNS) has been recently proposed as a valid alternative to VNS. The ear presents afferent vagus and trigeminal-nerve distribution; its innervation is the theoretical basis of different reflex therapies, including auriculotherapy. An increasing number of studies have shown that several therapeutic effects induced by invasive VNS and TNS, can be reproduced by noninvasive auricular-nerve stimulation. However, the sites and neurobiologic mechanisms by which VNS and TNS produce their therapeutic effects are not clear yet. Conclusions: Accumulating evidence suggests that VNS and TNS share multiple levels and mechanisms of action in the CNS.

[Unsatisfactory response: definition and involvement]

In the treatment of unipolar depression, treatment response is a key issue in terms of evolution and prognosis. Within this concept, the inadequate response includes the worsening, the lack of response, partial response and poor tolerance. This lack of response may be related to intrinsic factors to the individual, but also to more extrinsic environmental factors. In this review, we explore this concept through its links with adherence and treatment duration. In this field, the concept of early response can be a powerful indicator of therapeutic response, which conditions the prescription of antidepressants beyond the strict framework of the sufficient period of 4 to 6 weeks. In addition to its impact on prognosis, the literature data show that the insufficient response is a significant burden in terms of medical and economic cost, and somatic comorbidity; and justifies a systematic identification of this dimension. Therefore self-reports (QIDS; BDI) will be preferred to the clinician-rated depression symptom rating scales (MADRS, HAMD) that require a specific training. Identifying predictors of non-response would be an attractive target for prescribers but the results to date are not operative.

Efficacy and tolerability of switching therapy to vortioxetine versus other antidepressants in patients with major depressive disorder

OBJECTIVES

To assess the relative efficacy and tolerability of vortioxetine against different antidepressant monotherapies in patients with major depressive disorder (MDD) with inadequate response to selective serotonin reuptake inhibitor (SSRI) or serotonin-norepinephrine reuptake inhibitor (SNRI) therapy.

METHODS

A systematic search was conducted for monotherapy studies in patients with MDD with inadequate response to first-line therapy. Treatments included SSRIs, SNRIs, and other antidepressants. Identified studies underwent a three-stage screening/data extraction process and critical appraisal. Adjusted indirect treatment comparisons (ITCs) on systematic literature review outputs were made using Bucher's method, comparing remission rates and withdrawal rates due to adverse events (AEs).

RESULTS

Of 27 studies meeting the inclusion criteria, a few studies were of high quality according to the National Institute of Health and Care Excellence checklist. Three studies contributed to an evidence network for quantitative assessment comparing vortioxetine with agomelatine, sertraline, venlafaxine XR, and bupropion SR. Vortioxetine had a statistically significantly higher remission rate than agomelatine (risk difference [RD]: -11.0% [95% CI: -19.4; -2.6]), and numerically higher remission rates than sertraline (RD: -14.4% [95% CI: -29.9; 1.1]), venlafaxine (RD: -7.20% [95% CI: -24.3; 9.9]), and bupropion (RD: -10.70% [95% CI: -27.8; 6.4]). Withdrawal rates due to AEs were statistically significantly lower for vortioxetine than sertraline (RD: 12.1% [95% CI: 3.1; 21.1]), venlafaxine XR (RD: 12.3% [95% CI: 0.8; 23.8]), and bupropion SR (RD: 18.3% [95% CI: 6.4; 30.1]).

CONCLUSIONS

The current systematic literature review found a few high quality switch studies assessing monotherapies in patients with MDD with inadequate response to SSRI/SNRIs. ITCs indicated that switching to vortioxetine leads to numerically higher remission rates compared with other antidepressants. Vortioxetine is a well tolerated treatment, showing statistically lower withdrawal rates due to AEs compared with other antidepressants. Vortioxetine is a relevant therapeutic alternative in patients experiencing inadequate response to prior SSRI or SNRI therapy.

Antidepressant drug development: Focus on triple monoamine reuptake inhibition

Many patients with major depressive disorder (MDD) only partially respond, and some have no clinically meaningful response, to current widely used antidepressant drugs. Due to the purported role of dopamine in the pathophysiology of depression, triple-reuptake inhibitors (TRIs) that simultaneously inhibit serotonin (5-HT), norepinephrine (NE) and dopamine reuptake could be a useful addition to the armamentarium of treatments for MDD. A TRI should more effectively activate mesolimbic dopamine-related reward-networks, restore positive mood and reduce potent 5-HT reuptake blockade associated "hypodopaminergic" adverse effects of decreased libido, weight gain and "blunting" of emotions. On the other hand, dopaminergic effects raise concern over abuse liability and TRIs may have many of the cardiovascular effects associated with NET inhibition. Several clinical development programs for potential TRI antidepressants have failed to demonstrate significantly greater efficacy than placebo or standard of care. Successful late-stage clinical development of a TRI is more likely if experimental research studies in the target population of depressed patients have demonstrated target engagement that differentially and dose-dependently improves assessments of reward-network dysfunction relative to existing antidepressants. TRI treatment could be individualized on the basis of predictive markers such as the burden of decreased positive mood symptoms and/or neuroimaging evidence of reward network dysfunction. This review focuses on how the next generation of monoamine-based treatments could be efficiently developed to address unmet medical need in MDD.

Patient-reported outcomes before and after treatment of major depressive disorder

Patient reported outcomes (PROs) of quality of life (QoL), functioning, and depressive symptom severity are important in assessing the burden of illness of major depressive disorder (MDD) and to evaluate the impact of treatment. We sought to provide a detailed analysis of PROs before and after treatment of MDD from the large Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study. This analysis examines PROs before and after treatment in the second level of STAR*D. The complete data on QoL, functioning, and depressive symptom severity, were analyzed for each STAR*D level 2 treatment. PROs of QoL, functioning, and depressive symptom severity showed substantial impairments after failing a selective serotonin reuptake inhibitor trial using citalopram (level 1). The seven therapeutic options in level 2 had positive statistically (P values) and clinically (Cohen's standardized differences [Cohen's d]) significant impact on QoL, functioning, depressive symptom severity, and reduction in calculated burden of illness. There were no statistically significant differences between the interventions. However, a substantial proportion of patients still suffered from patient-reported QoL and functioning impairment after treatment, an effect that was more pronounced in nonremitters. PROs are crucial in understanding the impact of MDD and in examining the effects of treatment interventions, both in research and clinical settings.

Efficacy and safety of selegiline transdermal system (STS) for the atypical subtype of major depressive disorder: pooled analysis of 5 short-term, placebo-controlled trials

OBJECTIVE

The objective of the present study is to investigate the efficacy and safety of the selegiline transdermal system (STS) in major depressive disorder (MDD) with atypical features.

METHODS

This was a post-hoc analysis of 5 short-term trials. The atypical subtype was defined as the presence of at least 1 item with a score of 2 or greater from items 22-26 on the 28-item Hamilton Depression Rating Scale (HAMD-28), and a maximum score of 1 point for items 6 (insomnia late), 12 (somatic symptoms, gastrointestinal), and 16 (loss of weight) to exclude vegetative features of melancholic depression. The mean changes of HAMD-28 total score from baseline to the endpoint (response rate defined as ≥50% reduction in HAMD-28 scores and remission rate defined as ≤10 HAMD-28 total score at the treatment endpoint) were compared between atypical and nonatypical groups.

RESULTS

In this analysis, 352 subjects (STS = 168 vs placebo = 184) met the definition of atypical subtype at baseline. STS (n = 641) significantly decreased HAMD-28 total score compared with placebo (n = 648) from beginning to end of treatment (-10.7 ± 9.3 vs -9.4 ± 9.3; p = 0.014). STS showed comparable efficacy in patients with the atypical subtype compared with the nonatypical subtype for placebo-subtracted mean change in HAMD-28 total score (-2.11 ± 1.01 vs. -1.0 ± 0.60; p = 0.34), odds ratio (OR) for response (1.41 vs 1.23, p = 0.62), and OR for remission (1.77 vs 1.18, p = 0.22).

CONCLUSION

STS appears to be comparably efficacious and tolerable in atypical and nonatypical subtypes of MDD. Adequately powered, controlled, clinical trials are necessary to confirm our findings.

Patient-reported outcomes before and after treatment of major depressive disorder

Patient reported outcomes (PROs) of quality of life (QoL), functioning, and depressive symptom severity are important in assessing the burden of illness of major depressive disorder (MDD) and to evaluate the impact of treatment. We sought to provide a detailed analysis of PROs before and after treatment of MDD from the large Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study. This analysis examines PROs before and after treatment in the second level of STAR*D. The complete data on QoL, functioning, and depressive symptom severity, were analyzed for each STAR*D level 2 treatment. PROs of QoL, functioning, and depressive symptom severity showed substantial impairments after failing a selective serotonin reuptake inhibitor trial using citalopram (level 1). The seven therapeutic options in level 2 had positive statistically (P values) and clinically (Cohen's standardized differences [Cohen's d]) significant impact on QoL, functioning, depressive symptom severity, and reduction in calculated burden of illness. There were no statistically significant differences between the interventions. However, a substantial proportion of patients still suffered from patient-reported QoL and functioning impairment after treatment, an effect that was more pronounced in nonremitters. PROs are crucial in understanding the impact of MDD and in examining the effects of treatment interventions, both in research and clinical settings.

Treatment resistant depression: strategies for primary care

Depression is commonly diagnosed and treated in primary care. Recent evidence indicates that the majority of depressed patients will not fully recover with an initial antidepressant treatment. This paper reviews commonly used options for treatment after an inadequate initial antidepressant response. The alternatives range widely, and include escalating the dose of the initial antidepressant, switching to an alternative medication, combining two antidepressants with different mechanisms of action (e.g., bupropion + SSRI or mirtazapine + venlafaxine), adding other medications such as lithium or certain atypical antipsychotics (olanzapine, aripiprazole, or quetiapine) to the antidepressant, adding a natural product such as l-methylfolate or s-adenosylmethionine (SAMe), or adding cognitive behavioral psychotherapy. What agent to be used will depend on the comfort level of the primary care practitioner and the availability of Psychiatry referral. However, it is reasonable to take one or more additional steps to attempt to achieve remission.

Comparative effectiveness of second-generation antidepressants for accompanying anxiety, insomnia, and pain in depressed patients: a systematic review

BACKGROUND

Patients with major depressive disorder (MDD) often suffer from accompanying symptoms that influence the choice of pharmacotherapy with second-generation antidepressants (SGAs). We conducted a systematic review to determine the comparative effectiveness of citalopram, escitalopram, fluoxetine, fluvoxamine, paroxetine, sertraline, desvenlafaxine, duloxetine, venlafaxine, bupropion, mirtazapine, nefazodone, and trazodone, for accompanying anxiety, insomnia, and pain in patients with MDD.

METHODS

We conducted searches in multiple databases including MEDLINE®, Embase, the Cochrane Library, International Pharmaceutical Abstracts, and PsycINFO, from 1980 through August 2011 and reviewed reference lists of pertinent articles. We dually reviewed abstracts, full-text articles, and abstracted data. We included randomized, head-to-head trials of SGAs of at least 6 weeks' duration. We grouped SGAs into three classes for the analysis: selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors, and others. We graded the strength of the evidence as high, moderate, low, or very low based on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group (GRADE) approach.

RESULTS

We located 19 head-to-head trials in total: 11 on anxiety, six on insomnia, and four on pain. For the majority of comparisons, the strength of the evidence was moderate or low: evidence is weakened by inconsistency and imprecision. For treating anxiety, insomnia, and pain moderate evidence suggests that the SSRIs do not differ.

CONCLUSIONS

Evidence guiding the selection of an SGA based on accompanying symptoms of depression is limited. Very few trials were designed and adequately powered to answer questions about accompanying symptoms; analyses were generally of subgroups in larger MDD trials.