Combining norepinephrine and serotonin reuptake inhibition mechanisms for treatment of depression: a double-blind, randomized study

Lipopolysaccharide-binding protein expression is increased by stress and inhibits monoamine synthesis to promote depressive symptoms

Monoamine insufficiency is suggested to be associated with depressive features such as sadness, anhedonia, insomnia, and cognitive dysfunction, but the mechanisms that cause it are unclear. We found that the acute-phase protein lipopolysaccharide-binding protein (LBP) inhibits monoamine biosynthesis by acting as an endogenous inhibitor of dopamine-β-hydroxylase (DBH) and aromatic-L-amino-acid-decarboxylase (DDC). LBP expression was increased in individuals with depression and by diverse stress challenges in mice. LBP antibodies and LBP knockdown inhibited monoamine insufficiency and depression-like features in mice, which worsened with LBP overexpression or administration. Monoamine insufficiency and depression-like symptoms were not induced by stressful stimuli in LBP-deficient mice, further highlighting a role for LBP in stress-induced depression, and a peptide we designed that blocks LBP-DBH and LBP-DDC interactions showed anti-depression effects in mice. This study reveals an important role for LBP in regulating monoamine biosynthesis and suggests that targeting LBP may have potential as a treatment for some individuals with depression.

Combining Antidepressants vs Antidepressant Monotherapy for Treatment of Patients With Acute Depression: A Systematic Review and Meta-analysis

IMPORTANCE

Combining antidepressants is frequently done in the treatment of acute depression, but studies have yielded conflicting results.

OBJECTIVE

To conduct a systematic review and meta-analysis assessing efficacy and tolerability of combination therapy. Combinations using presynaptic α2-autoreceptor antagonists or bupropion were investigated separately.

DATA SOURCES

MEDLINE, Embase, PsycINFO, and the Cochrane Central Register of Controlled Trials were systematically searched from each database inception through January 2020.

STUDY SELECTION

Randomized clinical trials (RCTs) comparing combinations of antidepressants with antidepressant monotherapy in adult patients with acute depression were included.

DATA EXTRACTION AND SYNTHESIS

Following guidelines from Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) and recommendations from the Cochrane Handbook, 2 reviewers independently performed a literature search, study selection, data extraction, and evaluation of risk of bias. Data were pooled in random-effects analyses.

MAIN OUTCOMES AND MEASURES

Primary outcome was efficacy measured as standardized mean difference (SMD); secondary outcomes were response, remission, change from baseline in rating scale scores, number of dropouts, and number of dropouts due to adverse events.

RESULTS

Thirty-nine RCTs including 6751 patients were eligible. Combination treatment was statistically significantly associated with superior treatment outcomes relative to monotherapy (SMD = 0.31; 95% CI, 0.19-0.44). Combining a reuptake inhibitor with an antagonist of presynaptic α2-autoreceptors was superior to other combinations (SMD = 0.37; 95% CI, 0.19-0.55). Bupropion combinations were not superior to monotherapy (SMD = 0.10; 95% CI, -0.07 to 0.27). Numbers of dropouts and dropouts due to adverse events did not differ between treatments. Studies were heterogeneous, and there was indication of publication bias (Egger test result was positive; P = .007, df = 36), but results remained robust across prespecified secondary outcomes and sensitivity and subgroup analyses, including analyses restricted to studies with low risk of bias.

CONCLUSIONS AND RELEVANCE

In this meta-analysis of RCTs comparing combinations of antidepressants with antidepressant monotherapy, combining antidepressants was associated with superior treatment outcomes but not with more patients dropping out of treatment. Combinations using an antagonist of presynaptic α2-autoreceptors may be preferable and may be applied as a first-line treatment in severe cases of depression and for patients considered nonresponders.

Treatment-Resistant Depression in Poland—Epidemiology and Treatment

(1) Background: Major depressive disorder (MDD) is one of the most prevalent psychiatric disorders worldwide. Although several antidepressant drugs have been developed, up to 30% of patients fail to achieve remission, and acute remission rates decrease with the number of treatment steps required. The aim of the current project was to estimate and describe the population of treatment-resistant depression (TRD) patients in outpatient clinics in Poland. (2) Methods: The project involved a representative sample of psychiatrists working in outpatient clinics, chosen through a process of quota random sampling. The doctors completed two questionnaires on a consecutive series of patients with MDD, which captured the patients’ demographics, comorbidities, and medical histories. TRD was defined as no improvement seen after a minimum of two different antidepressant drug therapies applied in sufficient doses for a minimum of 4 weeks each. The data were weighted and extrapolated to the population of TRD outpatients in Poland. (3) Results: A total of 76 psychiatrists described 1781 MDD patients, out of which 396 fulfilled the criteria of TRD. The TRD patients constituted 25.2% of all MDD patients, which led to the number of TRD outpatients in Poland being estimated at 34,800. The demographics, comorbidities, medical histories, and histories of treatment of Polish TRD patients were described. In our sample of the TRD population (mean age: 45.6 ± 13.1 years; female: 64%), the patients had experienced 2.1 ± 1.6 depressive episodes (including the current one), and the mean duration of the current episode was 4.8 ± 4.4 months. In terms of treatment strategies, most patients (around 70%) received monotherapy during the first three therapies, while combination antidepressant drugs (ADs) were applied more often from the fourth line of treatment. The use of additional medications and augmentation was reported in only up to one third of the TRD patients. During all of the treatment steps, patients most often received a selective serotonin reuptake inhibitor (SSRI) and a serotonin norepinephrine reuptake inhibitor (SNRI). (4) Conclusions: TRD is a serious problem, affecting approximately one fourth of all depressive patients and nearly 35,000 Poles.

Polypharmacy- Purpose, Benefits and Limitations

With what has become increasingly common among nearly all medical specialties, the number of patients who have various comorbid diseases both psychiatrically and mentally challenges the field of psychiatry. As a result, it is not uncommon physicians are imposed with treatment decisions regarding polypharmacy- the use of multiple medications to treat either different diseases, or even many times, the same illness. In recent years the concept of polypharmacy has been known to have a negative undertone, implying its use is inappropriate or causing more harm than potential benefit. Although the use of any medication should involve a risk versus benefit discussion, when used with good clinical judgment and pharmacologically sound knowledge this practice can be potentially life altering for patients.

Potential antidepressant-like effect of piperazine derivative LQFM212 in mice: Role of monoaminergic pathway and brain-derived neurotrophic factor

Major depression disorder (MDD) is one of the most widespread and debilitating psychiatric diseases and may be associated with other mental disorders such as anxiety. Despite advances in neurobiology studies, currently no established mechanism can explain all facets of MDD, and available drugs often show therapeutic delay for clinical effectiveness and response rates in patients are around 50 %. Previous activities of piperazine derivatives on CNS are indicators of its therapeutic potential for treating mental disorders. In this regard, we have previously shown that the piperazine derivative 2,6-di-tert-butyl-4-((4-(2-hydroxyethyl)piperazin-1-yl)methyl)phenol (LQFM212) has anxiolytic-like activity which involves serotonergic pathway, nicotinic receptors and BZD-site of GABA_A receptor, without cognitive impairments. Herein, was evaluated the potential antidepressant-like effect of LQFM212 on forced swimming test (FST) after a single dose of 54 μmol/kg and after repeated treatment for 15 days in mice. Pretreatment with WAY-100635, PCPA, prazosin, SCH-23390, sulpiride or AMPT reversed the antidepressant-like effect on FST, suggesting that monoaminergic pathway contributes for effects of LQFM212. Furthermore, repeated treatment with LQFM212 increased hippocampal BDNF levels dosed by ELISA kit. In assessment of possible adverse effects, repeated treatment with LQFM212 did not alter the body weight of the animals, glutathione levels in the liver, and serum levels of AST, ALT, urea, and creatinine. Taken together, the results showed that LQFM212 has an antidepressant-like effect that involves monoaminergic pathway and increased BDNF levels. This compound represents promising candidate for prototype of psychoactive drugs for treatment of anxiety and depression disorders since these pathological conditions may exist in comorbidities.

Pharmacological Treatments for Patients with Treatment-Resistant Depression

Over a third of patients with major depressive disorder (MDD) do not have an adequate response to first-line antidepressant treatments, i.e., they have treatment-resistant depression (TRD). These patients tend to have a more severe course of illness and are at an increased risk of suicide. Next step treatment options for patients with TRD, include switching to a different antidepressant, combining more than one antidepressant, or augmenting an antidepressant with another (non-antidepressant) medication. It is unclear which of these treatment approaches should be applied to a given patient, and in what order. Due to this ambiguity, comparing antidepressants and augmentation agents on the basis of their efficacy, tolerability, and speed of symptom relief would be beneficial for clinicians. To accomplish this, a systematic search was conducted following PRISMA guidelines. Only randomized controlled trials were included in this qualitative synthesis, resulting in 66 articles. This review identified several effective pharmaco-therapeutic strategies that are currently available for patients with TRD. Ketamine and esketamine appear to be effective for the treatment of TRD. Augmentation with certain second generation antipsychotics, such as quetiapine or aripiprazole is likewise effective, and may be preferred over switching to antidepressant monotherapy. While the combination of olanzapine and fluoxetine was one of the first pharmacotherapy approved for TRD, and its use may be limited by metabolic side-effects. Other effective strategies include augmentation with lithium, liothyronine (T3), lamotrigine, or combination of antidepressants including bupropion, tricyclics, or mirtazapine. There is insufficient research to demonstrate the efficacy of ziprasidone or levothyroxine (T4). A shared decision-making approach is recommended to guide treatment selection to address each patient’s individual needs.

Hamilton scale and MADRS are interchangeable in meta-analyses but can disagree at trial level

BACKGROUND AND OBJECTIVE

Major depressive disorder is a multidimensional disease, in which demonstrating the efficacy of treatments is difficult. The Hamilton Rating Scale for Depression (HRSD) and the Montgomery-Asberg Depression Rating Scale (MADRS) cover different domains but are used interchangeably as primary measures of the outcome in trials and-with standardized measures-in meta-analyses. We aimed at understanding (i) whether the choice of the outcome measurement tool can influence the outcome of a trial, and if so, (ii) whether one systematically outperforms the other, and (iii) whether using standardized measures of the effect in meta-analysis is justified.

METHODS

Short-term randomized trials in patients with major depressive disorder that used both the scales were systematically searched and the results were collected. To quantify the differences in the results-both in terms of the standardized mean difference (SMD) and odds ratio (OR) for response-and their range, data were analyzed and plotted with the Bland-Altman method.

RESULTS

161 comparisons from 80 studies were included, involving a total of 18,189 patients. Neither of the two scales appears systematically more sensitive to the treatment effect than the other in terms of SMDs (P-value = 0.06, 95% CI -0.044 to 0.001) or ORs (P-value = 0.15, 95% CI -0.25 to 0.04). However, the variability of differences between the HRSD and MADRS largely depends on the number of patients included in the comparison.

CONCLUSION

No systematic differences between the two scales were found supporting the use of standardized measures in meta-analyses. However, the same trial may give very different results with either scale, especially in small trials. Further research is needed to understand the causes of this variability.

The effects of intramuscular administration of scopolamine augmentation in moderate to severe major depressive disorder: a randomized, double-blind, placebo-controlled trial

INTRODUCTION

Major depressive disorder (MDD) is a common affective disorder. Currently established pharmacotherapies lack rapid clinical response, thereby limiting their ability to bring instant relief to patients. A series of clinical trials has demonstrated the antidepressant effects of scopolamine, yet few have studied the effects of add-on scopolamine to currently available antidepressants. It is not known whether conventional antidepressant treatment with a 3-day scopolamine injection could speed up oral antidepressant efficacy. The main focus of this study is to detect the capacity of the rapid-onset efficacy of such a treatment option.

METHODS AND ANALYSIS

This study consisted of a single-centre, double-blind, three-arm randomized trial with a 4-week follow-up period. Sixty-six participants meeting entry criteria were randomly allocated to three treatment groups: a high-dose group, a low-dose group and a placebo control group. Psychiatric rating scales were administered at baseline and seven viewing points following the administration of intramuscular injections. The primary outcome measure was length of time from randomization (baseline) to early improvement.

RESULTS

Both primary and secondary outcome measures consistently showed no differences among the three groups. The cumulative response rate and the remission rate were 72.7% (48/66) and 47.0% (31/66). Intramuscular scopolamine treatment was relatively well tolerated. Two subjects with high-dose injections dropped out because of a drug-related side effect.

CONCLUSION

Contrary to our prediction, we found that, compared to placebo (0.9% saline i.m.), scopolamine was not associated with a significantly faster antidepressant response rate.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03131050. Registered on 18 April 2017.

Pharmacological targeting of β2 -adrenoceptors is neuroprotective in the LPS inflammatory rat model of Parkinson's disease

BACKGROUND AND PURPOSE

Chronic inflammation may play a role in the pathogenesis of Parkinson's disease (PD). Noradrenaline is an endogenous neurotransmitter with anti-inflammatory properties. In the present investigation, we assessed the immunomodulatory and neuroprotective efficacy of pharmacologically targeting the CNS noradrenergic system in a rat model of PD.

EXPERIMENTAL APPROACH

The impact of treatment with the β2 -adrenoceptor agonists clenbuterol and formoterol was assessed in the intranigral LPS rat model of PD. The immunomodulatory potential of formoterol to influence the CNS response to systemic inflammation was also assessed.

KEY RESULTS

LPS-induced deficits in motor function (akinesia and forelimb-use asymmetry) and nigrostriatal dopamine loss were rescued by both agents. Treatment with the noradrenaline reuptake inhibitor atomoxetine reduced striatal dopamine loss and motor deficits following intranigral LPS injection. Co-treatment with the β2 -adrenoceptor antagonist ICI 118,551 attenuated the protective effects of atomoxetine. Systemic LPS challenge exacerbated reactive microgliosis, IL-1β production, dopamine cell loss in the substantia nigra, nerve terminal degeneration in the striatum, and associated motor impairments in animals that previously received intranigral LPS. This exacerbation was attenuated by formoterol treatment.

CONCLUSION AND IMPLICATIONS

The results indicate that pharmacologically targeting β2 -adrenoceptors has the propensity to regulate the neuroinflammatory phenotype in vivo and may be a potential neuroprotective strategy where inflammation contributes to the progression of dopaminergic neurodegeneration. In accordance with this, clinical agents such as β2 -adrenoceptor agonists may prove useful as immunomodulatory agents in the treatment of neurodegenerative conditions associated with brain inflammation.

Lithium Augmentation Versus Citalopram Combination in Imipramine-Resistant Major Depression: A 10-Week Randomized Open-Label Study

PURPOSE/BACKGROUND

According to available international clinical guides, tricyclic antidepressants are our first- or second-line treatment of choice for severe unipolar major depression. However, the therapeutic option after an unsuccessful response to a tricyclic antidepressant drug in unipolar major depression is still unclear.

METHODS/PROCEDURES

This 10-week randomized open-label study assessed the effectiveness of add-on lithium (adjusted to plasma levels) compared with add-on citalopram (30 mg/d) in 104 severe unipolar major depressive patients after a 10-week unsuccessful imipramine (adjusted to plasma level). Efficacy analyses examined changes in the severity of depression symptoms from baseline visit to endpoint and the comparative remission rate between treatment subgroups.

FINDINGS/RESULTS

The randomized sample consisted of 104 imipramine-resistant severe unipolar major depressed patients. Both, the percentage of remitters (40.4% vs 21.1%, P = 0.034) and the mean reduction of the Hamilton Depression Rating Scale score (58.8% vs 42.5%, P = 0.005) were significantly greater in the add-on citalopram subgroup at endpoint visit.

IMPLICATIONS/CONCLUSIONS

Although we should be cautious about generalizing these results to patients with a less severe unipolar major episode, results from the present study suggest that add-on citalopram is a very effective treatment option in unipolar major depressive episodes after an unsuccessful imipramine regimen.

Venlafaxine ER Blocks the Norepinephrine Transporter in the Brain of Patients with Major Depressive Disorder: a PET Study Using [18F]FMeNER-D2

BACKGROUND

The in vivo binding of clinical dose of venlafaxine on norepinephrine transporter has been questioned because venlafaxine has higher in vitro affinity to serotonin transporter than that to norepinephrine transporter. Although serotonin transporter occupancy of clinically relevant doses of venlafaxine has been reported, there has been no report of norepinephrine transporter occupancy in the human brain.

METHODS

This was an open-label, single center, exploratory positron emission tomography study. Twelve major depressive disorder patients who had responded to venlafaxine extended-release and 9 control subjects were recruited. Each subject participated in one positron emission tomography measurement with [18F]FMeNER-D2. Binding potential in brain was quantified by the area under the curve ratio method with thalamus as target and white matter as reference regions. The difference of binding potential values between control and patient groups divided to 2 dose ranges were evaluated. Norepinephrine transporter occupancy (%) for all the major depressive disorder patients was calculated using mean binding potential of control subjects as baseline. The relationships between dose or plasma concentration of total active moiety and occupancies of norepinephrine transporter were also estimated.

RESULTS

The binding potential of the patient group with 150 to 300 mg/d was significantly lower than that in the control subjects group (P = .0004 < .05/2). The norepinephrine transporter occupancy (8-61%) increased in a dose-dependent manner although a clear difference beyond 150 mg/d was not observed.

CONCLUSIONS

This study demonstrates that clinically relevant doses of venlafaxine extended-release block the norepinephrine transporter of the major depressive disorder patient's brain. The data support the notion that the antidepressant effect of venlafaxine involves a combination of serotonin transporter and norepinephrine transporter blockades.

Combining antidepressants: a review of evidence

Sequenced (stepped) treatment approaches are widely endorsed in the management of depression. Combining antidepressants is a recognised step for those failing to respond to monotherapy. Despite the limited evidence base, this strategy is widely used by clinicians in practice. Not every combination used clinically has a sound neuropharmacological rationale and the use of such combinations may increase the side-effect burden without any additional advantage to the patient. Efficacy of various antidepressant combinations along with the data on side-effect profile and toxicity of such combined treatments are reviewed here. The different combinations are considered by each class of antidepressant available in the UK.

Optimized regimens of combined medications for the treatment of major depressive disorder: a double-blind, randomized-controlled trial

INTRODUCTION

This study investigated if optimized dose regimens of escitalopram and bupropion combination from treatment initiation can be superior to either drug alone in speed of onset, remission rate, and maintenance of therapeutic efficacy.

METHODS

Patients from a single site (N=85) within a larger double-blind 12-week trial (N=245) showed a lower dropout rate (14% vs 40%) and used higher doses; therefore, this cohort was analyzed separately. Uniquely at this single site, after 12 weeks, non-remitters on a single drug received the other one in addition and combination non-remitters underwent a switch of escitalopram for duloxetine for a 6-week period. Escitalopram could be given up to 40 mg/day and bupropion up to 450 mg/day. A 6-month prolongation was then implemented in remitters, maintaining the double-blind design throughout. Remission was defined as ≤7 on the 17-item Hamilton Rating Scale for Depression, as in the initial publication.

RESULTS

At week 2, combination treatment was superior in remission rate (5/28) compared with both bupropion (0/26) and escitalopram monotherapies (0/31; P=0.03 and P=0.02, respectively). The week 12 remission rate of combination treatment showed a higher rate (15/28) relative to bupropion monotherapy (7/26; P=0.04), but not statistically different from escitalopram monotherapy (11/31; P=0.13). The 6-week augmentation produced remission in 7/21 monotherapy non-remitters and 0/6 in the switch group (P=0.13). Remission was sustained in 28/31 patients enrolled in the 6-month maintenance.

CONCLUSION

These results suggest that combination of escitalopram and bupropion from treatment initiation is superior to either monotherapy in speed of onset. The addition of a second drug in non-remitters can lead to additional remissions, as shown with other combinations of medications. Treatment prolongation using optimized regimens leads to low relapse rates.

Molecular mechanism of noradrenaline during the stress-induced major depressive disorder

Chronic stress-induced depression is a common hallmark of many psychiatric disorders with high morbidity rate. Stress-induced dysregulation of noradrenergic system has been implicated in the pathogenesis of depression. Lack of monoamine in the brain has been believed to be the main causative factor behind pathophysiology of major depressive disorder (MDD) and several antidepressants functions by increasing the monoamine level at the synapses in the brain. However, it is undetermined whether the noradrenergic receptor stimulation is critical for the therapeutic effect of antidepressant. Contrary to noradrenergic receptor stimulation, it has been suggested that the desensitization of β-adrenoceptor is involved in the therapeutic effect of antidepressant. In addition, enhanced noradrenaline (NA) release is central response to stress and thought to be a risk factor for the development of MDD. Moreover, fast acting antidepressant suppresses the hyperactivation of noradrenergic neurons in locus coeruleus (LC). However, it is unclear how they alter the firing activity of LC neurons. These inconsistent reports about antidepressant effect of NA-reuptake inhibitors (NRIs) and enhanced release of NA as a stress response complicate our understanding about the pathophysiology of MDD. In this review, we will discuss the role of NA in pathophysiology of stress and the mechanism of therapeutic effect of NA in MDD. We will also discuss the possible contributions of each subtype of noradrenergic receptors on LC neurons, hypothalamic-pituitary-adrenal axis (HPA-axis) and brain derived neurotrophic factor-induced hippocampal neurogenesis during stress and therapeutic effect of NRIs in MDD.

Effect of memantine combination therapy on symptoms in patients with moderate-to-severe depressive disorder: randomized, double-blind, placebo-controlled study

WHAT IS KNOWN AND OBJECTIVE

Current treatments for depressive disorders are far from optimum. This study was planned to evaluate possible antidepressant effects and safety of memantine, a selective N-methyl-d-aspartate receptor antagonist, in humans.

METHODS

Sixty-six outpatients with the diagnosis of moderate-to-severe major depressive disorder, based on DSM-V diagnostic criteria, were recruited to participate in a parallel, randomized, controlled trial. Sixty-two participants completed 6 weeks of treatment with either memantine (20 mg/day) plus sertraline (200 mg/day) or placebo plus sertraline (200 mg/day). Patients were evaluated using the Hamilton Depression Rating Scale (HDRS) at baseline and at weeks 2, 4 and 6. Comparison of treatment efficacy in improving depressive symptoms between the two groups was the principal outcome measure.

RESULTS AND DISCUSSION

A repeated-measures analysis demonstrated significant time × treatment interaction on HDRS score [F (2·09, 125·67) = 5·09, P = 0·007]. Significantly greater improvement was seen at all three follow-up sessions as well as significantly greater response rates at weeks 4 and 6 (P = 0·018 and P < 0·001, respectively) in the memantine group. Significantly more early improvers and more rapid response to treatment were observed in the memantine group (P = 0·001 and P < 0·001, respectively). A significant reduction was observed in HDRS score from baseline to the study endpoint in both memantine (P < 0·001, Cohen's d = 12·71) and placebo groups (P < 0·001, Cohen's d = 5·13). No serious adverse event occurred. No significantly greater remission rate was seen in the adjunctive memantine therapy.

WHAT IS NEW AND CONCLUSION

A 6-week course of treatment with memantine as adjunct to sertraline showed a favourable safety and efficacy profile in patients with major depressive disorder. Nonetheless, larger controlled studies of longer duration are necessary to assess long-term safety, efficacy and optimal dosing.

The Effects of Methylphenidate on Resting-State Functional Connectivity of the Basal Nucleus of Meynert, Locus Coeruleus, and Ventral Tegmental Area in Healthy Adults

Background: Methylphenidate (MPH) influences catecholaminergic signaling. Extant work examined the effects of MPH on the neural circuits of attention and cognitive control, but few studies have investigated the effect of MPH on the brain's resting-state functional connectivity (rsFC).

Methods: In this observational study, we compared rsFC of a group of 24 healthy adults who were administered an oral 45 mg dose of MPH with a group of 24 age and gender matched controls who did not receive MPH. We focused on three seed regions: basal nucleus of Meynert (BNM), locus coeruleus (LC), and ventral tegmental area/substantia nigra, pars compacta (VTA/SNc), each providing cholinergic, noradrenergic and dopaminergic inputs to the cerebral cortex. Images were pre-processed and analyzed as in our recent work (Li et al., 2014; Zhang et al., 2015). We used one-sample t-test to characterize group-specific rsFC of each seed region and two-sample t-test to compare rsFC between groups.

Results: MPH reversed negative connectivity between BNM and precentral gyri. MPH reduced positive connectivity between LC and cerebellum, and induced positive connectivity between LC and right hippocampus. MPH decreased positive VTA/SNc connectivity to the cerebellum and putamen, and reduced negative connectivity to left middle occipital gyrus.

Conclusion: MPH had distinct effects on the rsFC of BNM, LC, and VTA/SNc in healthy adults. These new findings may further our understanding of the role of catecholaminergic signaling in Attention Deficit Hyperactivity Disorder (ADHD) and Parkinson's disease and provide insights into the therapeutic mechanisms of MPH in the treatment of clinical conditions that implicate catecholaminergic dysfunction.

[Switching and combining strategies of antidepressant medications]

Switching antidepressant medication may be helpful in depressed patients having no benefit from the initial antidepressant treatment. Before considering switching strategy, the initial antidepressant treatment should produce no therapeutic effect after at least 4 weeks of administration at adequate dosage. Choosing an antidepressant of pharmacologically distinct profile fails to consistently demonstrate a significant superiority in terms of effectiveness over the switching to another antidepressant within the same pharmacological class. Augmenting SSRI/SNRIs with mirtazapine/mianserin has become the most recommended strategy of antidepressant combinations. Augmenting SSRI with tricyclic drugs is now a less recommended strategy of antidepressant combinations given the increased risk for the occurrence of pharmacokinetic drug-drug interactions and adverse effects.

Combining Antidepressants in Acute Treatment of Depression: A Meta-Analysis of 38 Studies Including 4511 Patients

OBJECTIVE

Combining antidepressants (ADs) for therapy of acute depression is frequently employed, but randomized studies have yielded conflicting results. We conducted a systematic review and meta-analysis aimed at determining efficacy and tolerability of combination therapy.

METHODS

MEDLINE, Embase, PsycINFO, and CENTRAL databases were systematically searched through March 2014 for controlled studies comparing combinations of ADs with AD monotherapy in adult patients suffering from acute depression. The prespecified primary outcome was standardized mean difference (SMD), secondary outcomes were response, remission, and dropouts.

RESULTS

Among 8688 articles screened, 38 studies were eligible, including 4511 patients. Combination treatment was statistically, significantly superior to monotherapy (SMD 0.29; 95% CI 0.16 to 0.42). During monotherapy, slightly fewer patients dropped out due to adverse events (OR 0.90; 95% CI 0.53 to 1.53). Studies were heterogeneous (I(2) = 63%), and there was indication of moderate publication bias (fail-safe N for an effect of 0.1:44), but results remained robust across prespecified secondary outcomes and subgroups, including analyses restricted to randomized controlled trials and low risk of bias studies. Meta-regression revealed an association of SMD with difference in imipramine-equivalent dose. Combining a reuptake inhibitor with an antagonist of presynaptic α2-autoreceptors was superior to other combinations.

CONCLUSION

Combining ADs seems to be superior to monotherapy with only slightly more patients dropping out. Combining a reuptake inhibitor with an antagonist of presynaptic α2-autoreceptors seems to be significantly more effective than other combinations. Overall, our search revealed a dearth of well-designed studies.

Safety and tolerability of antidepressant co-treatment in acute major depressive disorder: results from a systematic review and exploratory meta-analysis

INTRODUCTION

Although antidepressant (AD) monotherapy is recommended first-line for major depressive disorder (MDD), AD + AD co-treatment is common.

AREAS COVERED

We conducted the first systematic review searching PubMed/MEDLINE/PsycInfo/Embase from database inception until 1 June 2015 for acute randomized trials in ≥ 20 adults with MDD comparing AD monotherapy with AD + AD co-treatment that reported quantitative data on adverse events (AEs). Meta-analyzing 23 studies (n = 2435, duration = 6.6 weeks) AD monotherapy and AD + AD co-treatment were similar regarding intolerability-related discontinuation (risk ratio [RR] = 1.38, 95% CI = 0.89 - 1.10) and frequency of ≥ 1 AE (RR = 1.19, 95% CI = 0.95 - 1.49). Nevertheless, AD + AD co-treatment was associated with significantly greater burden regarding 4/25 AEs (tremor: RR = 1.55, 95% CI = 1.01 - 2.38; sweating: RR = 1.95, 95% CI = 1.13 -3.38, ≥ 7% weight gain: RR = 3.15, 95% CI = 1.34 - 7.41; weight gain = 2.17, 95% CI = 0.71 - 3.63 kg), but not more CNS, gastrointestinal, sexual or alertness-related AEs. However, 11/25 AEs (44.0%) were reported in only 1 - 2 studies. Adding noradrenergic and specific serotonergic antidepressants (NaSSA) or tricyclic antidepressants (TCA) to selective serotonin reuptake inhibitors (SSRIs) was specifically associated with more AEs.

EXPERT OPINION

The potential for increased AEs with AD + AD co-treatment needs to be considered vis-à-vis unclear efficacy benefits of this strategy. In particular, NaSSAs and TCAs should be added to SSRIs with caution. Clearly, more data on side-effect burden of AD + AD co-treatment are needed.

Evidence-based guidelines for treating depressive disorders with antidepressants: A revision of the 2008 British Association for Psychopharmacology guidelines

A revision of the 2008 British Association for Psychopharmacology evidence-based guidelines for treating depressive disorders with antidepressants was undertaken in order to incorporate new evidence and to update the recommendations where appropriate. A consensus meeting involving experts in depressive disorders and their management was held in September 2012. Key areas in treating depression were reviewed and the strength of evidence and clinical implications were considered. The guidelines were then revised after extensive feedback from participants and interested parties. A literature review is provided which identifies the quality of evidence upon which the recommendations are made. These guidelines cover the nature and detection of depressive disorders, acute treatment with antidepressant drugs, choice of drug versus alternative treatment, practical issues in prescribing and management, next-step treatment, relapse prevention, treatment of relapse and stopping treatment. Significant changes since the last guidelines were published in 2008 include the availability of new antidepressant treatment options, improved evidence supporting certain augmentation strategies (drug and non-drug), management of potential long-term side effects, updated guidance for prescribing in elderly and adolescent populations and updated guidance for optimal prescribing. Suggestions for future research priorities are also made.

When is antidepressant polypharmacy appropriate in the treatment of depression?

Depression is a serious medical condition that is often only partially improved or completely unchanged after standard treatment with antidepressant medications. Various approaches have been developed to treat this subgroup of individuals with ‘treatment-resistant’ depression; but many individuals continue to live with chronic depressive symptoms that seriously affect their quality of life and overall functioning. One relatively new strategy is ‘antidepressant polypharmacy’ – simultaneously administering two or more antidepressant medications. Given the heterogeneity of the etiology of depression, this approach could improve therapeutic outcomes by concurrently activating multiple neurological pathways with different mechanisms of action, but there is also the risk that using multiple antidepressants would increase the prevalence and severity of side effects. Further work is needed to assess the potential benefits and risks of this strategy to managing treatmentresistant depression.

Pharmacological treatment approaches to difficult-to-treat depression

In the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) trial of almost 3000 patients with depression in the United States, 50% responded to the initial trial of a selective serotonin reuptake inhibitor antidepressant, but only a third achieved remission (nil or minimal depressive symptoms). The final remission rate, even after four potential treatment steps, was only 70%. This finding reflects the reality of clinical practice and highlights the need to employ the best available evidence in the management of people with complex depression. Before adopting a pharmacological strategy for a patient with difficult-to-treat depression, general clinical issues (such as missed psychiatric diagnoses, unresolved psychological issues and treatment non-adherence) should be considered. While there is no strong evidence for the order of implementing evidence-based pharmacological strategies for difficult-to-treat depression, we recommend: i) increase antidepressant dose; ii) switch to different antidepressant; iii) augment with a non-antidepressant agent; and iv) combine antidepressants. Sometimes it may be more appropriate to consider augmentation before switching antidepressants. The use of psychological interventions or other physical treatments such as electroconvulsive therapy should be considered at each step in management.

Emerging antidepressants to treat major depressive disorder

Depression is a common disorder with an annual risk of a depressive episode in the United States of 6.6%. Only 30-40% of patients remit with antidepressant monotherapy, leaving 60-70% of patients who do not optimally respond to therapy. Unremitted depressive patients are at increased risk for suicide. Considering the prevalence of treatment resistant depression and its consequences, treatment optimization is imperative. This review summarizes the latest treatment modalities for major depressive disorder including pharmacotherapy, electroconvulsive therapy, repetitive transcranial magnetic stimulation and psychotherapy. Through advancements in research to better understand the pathophysiology of depression, advances in treatment will be realized.

Efficacy and safety of olanzapine/fluoxetine combination vs fluoxetine monotherapy following successful combination therapy of treatment-resistant major depressive disorder

This study assessed prevention of relapse in patients with treatment-resistant depression (TRD) taking olanzapine/fluoxetine combination (OFC). Patients with major depressive disorder (MDD) who failed to satisfactorily respond to ≥ 2 different antidepressants for ≥ 6 weeks within the current MDD episode were acutely treated for 6-8 weeks, followed by stabilization (12 weeks) on OFC. Those who remained stable were randomized to OFC or fluoxetine for up to 27 weeks. Time-to-relapse was the primary efficacy outcome defined as 50% increase in Montgomery-Åsberg Depression Rating Scale score with Clinical Global Impressions-Severity of Depression score of ≥ 4; hospitalization for depression or suicidality; or discontinuation for lack of efficacy or worsening of depression or suicidality. A total of 444 patients were randomized 1:1 to OFC (N=221) or fluoxetine (N=223). Time-to-relapse was significantly longer in OFC-treated patients compared with fluoxetine-treated patients (p<0.001). Treatment-emergent weight gain and some mean and categorical fasting metabolic changes were significantly greater in OFC-treated patients. Clinically significant weight gain (≥ 7%) was observed in 55.7% of patients who remained on OFC throughout the study, including the relapse-prevention phase (up to 47 weeks). There were no significant differences between patients treated with OFC and fluoxetine in extrapyramidal symptoms or serious adverse events. We believe this is the first controlled relapse-prevention study in subjects with TRD that supports continued use of a second-generation antipsychotic beyond stabilization. A thorough assessment of benefits and risks (in particular metabolic changes) associated with continuing treatment with OFC or fluoxetine must be done based on individual patient needs.

Combination antidepressant therapy for major depressive disorder: speed and probability of remission

INTRODUCTION

Only about a third of patients with an episode of major depressive disorder remit with a given treatment and few remissions occur within the first weeks of treatment. This study tested whether combining escitalopram and bupropion as initial treatment would result in quicker remission and a higher remission rate than monotherapy with either drug.

METHOD

Two hundred forty-five outpatients aged 18-65 having non-psychotic, non-bipolar major depression were randomly assigned to double-blind treatment with bupropion or escitalopram or the combination dosed to a maximum of bupropion 450 mg/d and/or escitalopram 40 mg/d for 12 weeks. A Montgomery-Asberg Depression Rating Scale score of 22 was required for randomization, while a Hamilton Rating Scale for Depression score ≤ 7 defined remission. We hypothesized that bupropion plus escitalopram would outperform both monotherapies in both earlier onset of remission and higher rate of remission.

RESULTS

Primary analyses did not demonstrate that dual therapy outperformed both monotherapies in either timing of remission or remission rate. All three treatments were well tolerated.

DISCUSSION

These results do not support initial use of bupropion plus escitalopram to speed or enhance antidepressant response.

CLINICAL TRIALS REGISTRATION

NCT00519428.

Evidence-based, pharmacological treatment guideline for depression in Korea, revised edition

This paper aims to introduce, summarize, and emphasize the importance of the 'Evidence-Based, Pharmacological Treatment Guideline for Depression in Korea, Revised Edition'. The guideline broadly covers most aspects of the pharmacological treatment of patients in Korea diagnosed with moderate to severe major depression according to the DSM-IV TR. The guideline establishment process involved determining and answering a number of key questions, searching and selecting publications, evaluating recommendations, preparing guideline drafts, undergoing external expert reviews, and obtaining approval. A guideline adaptation process was conducted for the revised edition. The guideline strongly recommends pharmacological treatment considered appropriate to the current clinical situation in Korea, and should be considered helpful when selecting the appropriate pharmacological treatment of patients diagnosed with major depressive disorder. Therefore, the wide distribution of this guideline is recommended.

Combination pharmacotherapy in unipolar depression

It is estimated that between 60 and 80% of those with major depressive disorder do not achieve full symptomatic remission from first-line antidepressant monotherapy. Residual depressive symptoms substantially impair quality of life and add to the risk of recurrence. It is now clear that depression would benefit from more vigorous treatment, in order to ameliorate its disease burden. While there are established algorithms in situations of treatment resistance, the use of combination pharmacotherapy in unipolar depression is a relatively under-investigated area of treatment and may be an effective and tolerable strategy that maximizes the available resources. This paper reviews the current evidence for combination pharmacotherapy in unipolar depression and discusses its clinical applications.

Antidepressant combinations: cutting edge psychopharmacology or passing fad?

This article reviews the rationale for and history of combining antidepressants, as well as the current state of the evidence, in the treatment of major depression. Although it has long been suggested that some individuals may benefit from regimens that combine two dissimilar antidepressants, enthusiasm for this practice has waxed and waned and there was never a strong empirical foundation to support this practice. The tangibly better safety profiles of the newer generation antidepressants, both singly and in combination, have permitted greater use of such combinations in contemporary practice than ever before. Combinations that pair a selective serotonin reuptake inhibitor (SSRI) or serotonin norepinephrine reuptake inhibitor (SNRI) with a dissimilar antidepressant, such as bupropion or mirtazapine, are now widely used for patients who have not responded to trials of first- or second-line antidepressant monotherapies and have been tested as a potential way of speeding the benefits of treatment. However, there still is no strong evidence that even the most widely used combinations have particular merit and clinicians should be mindful that alternatives exist with more established efficacy. Moreover, aside from selected cases of drug-drug interactions, it may take full therapeutic doses of both drugs across a typically adequate duration of exposure to achieve the desired effects of combined treatment.

Fluoxetine versus other types of pharmacotherapy for depression

BACKGROUND

Depression is common in primary care and is associated with marked personal, social and economic morbidity, thus creating significant demands on service providers. The antidepressant fluoxetine has been studied in many randomised controlled trials (RCTs) in comparison with other conventional and unconventional antidepressants. However, these studies have produced conflicting findings.Other systematic reviews have considered selective serotonin reuptake inhibitor (SSRIs) as a group which limits the applicability of the indings for fluoxetine alone. Therefore, this review intends to provide specific and clinically useful information regarding the effects of fluoxetine for depression compared with tricyclics (TCAs), SSRIs, serotonin-noradrenaline reuptake inhibitors (SNRIs), monoamineoxidase inhibitors (MAOIs) and newer agents, and other conventional and unconventional agents.

OBJECTIVES

To assess the effects of fluoxetine in comparison with all other antidepressive agents for depression in adult individuals with unipolar major depressive disorder.

SEARCH METHODS

We searched the Cochrane Collaboration Depression, Anxiety and Neurosis Review Group Controlled Trials Register (CCDANCTR)to 11May 2012. This register includes relevant RCTs from the Cochrane Central Register of Controlled Trials (CENTRAL) (all years),MEDLINE (1950 to date), EMBASE (1974 to date) and PsycINFO (1967 to date). No language restriction was applied. Reference lists of relevant papers and previous systematic reviews were handsearched. The pharmaceutical company marketing fluoxetine and experts in this field were contacted for supplemental data.

SELECTION CRITERIA

All RCTs comparing fluoxetine with any other AD (including non-conventional agents such as hypericum) for patients with unipolar major depressive disorder (regardless of the diagnostic criteria used) were included. For trials that had a cross-over design only results from the first randomisation period were considered.

DATA COLLECTION AND ANALYSIS

Data were independently extracted by two review authors using a standard form. Responders to treatment were calculated on an intention-to-treat basis: dropouts were always included in this analysis. When data on dropouts were carried forward and included in the efficacy evaluation, they were analysed according to the primary studies; when dropouts were excluded from any assessment in the primary studies, they were considered as treatment failures. Scores from continuous outcomes were analysed by including patients with a final assessment or with the last observation carried forward. Tolerability data were analysed by calculating the proportion of patients who failed to complete the study due to any causes and due to side effects or inefficacy. For dichotomous data, odds ratios (ORs) were calculated with 95% confidence intervals (CI) using the random-effects model. Continuous data were analysed using standardised mean differences (SMD) with 95% CI.

MAIN RESULTS

A total of 171 studies were included in the analysis (24,868 participants). The included studies were undertaken between 1984 and 2012. Studies had homogenous characteristics in terms of design, intervention and outcome measures. The assessment of quality with the risk of bias tool revealed that the great majority of them failed to report methodological details, like the method of random sequence generation, the allocation concealment and blinding. Moreover, most of the included studies were sponsored by drug companies, so the potential for overestimation of treatment effect due to sponsorship bias should be considered in interpreting the results. Fluoxetine was as effective as the TCAs when considered as a group both on a dichotomous outcome (reduction of at least 50% on the Hamilton Depression Scale) (OR 0.97, 95% CI 0.77 to 1.22, 24 RCTs, 2124 participants) and a continuous outcome (mean scores at the end of the trial or change score on depression measures) (SMD 0.03, 95% CI -0.07 to 0.14, 50 RCTs, 3393 participants). On a dichotomousoutcome, fluoxetine was less effective than dothiepin or dosulepin (OR 2.13, 95% CI 1.08 to 4.20; number needed to treat (NNT) =6, 95% CI 3 to 50, 2 RCTs, 144 participants), sertraline (OR 1.37, 95% CI 1.08 to 1.74; NNT = 13, 95% CI 7 to 58, 6 RCTs, 1188 participants), mirtazapine (OR 1.46, 95% CI 1.04 to 2.04; NNT = 12, 95% CI 6 to 134, 4 RCTs, 600 participants) and venlafaxine(OR 1.29, 95% CI 1.10 to 1.51; NNT = 11, 95% CI 8 to 16, 12 RCTs, 3387 participants). On a continuous outcome, fluoxetine was more effective than ABT-200 (SMD -1.85, 95% CI -2.25 to -1.45, 1 RCT, 141 participants) and milnacipran (SMD -0.36, 95% CI-0.63 to -0.08, 2 RCTs, 213 participants); conversely, it was less effective than venlafaxine (SMD 0.10, 95% CI 0 to 0.19, 13 RCTs,3097 participants). Fluoxetine was better tolerated than TCAs considered as a group (total dropout OR 0.79, 95% CI 0.65 to 0.96;NNT = 20, 95% CI 13 to 48, 49 RCTs, 4194 participants) and was better tolerated in comparison with individual ADs, in particular amitriptyline (total dropout OR 0.62, 95% CI 0.46 to 0.85; NNT = 13, 95% CI 8 to 39, 18 RCTs, 1089 participants), and among the newer ADs ABT-200 (total dropout OR 0.18, 95% CI 0.08 to 0.39; NNT = 3, 95% CI 2 to 5, 1 RCT, 144 participants), pramipexole(total dropout OR 0.12, 95% CI 0.03 to 0.42, NNT = 3, 95% CI 2 to 5, 1 RCT, 105 participants), and reboxetine (total dropout OR0.60, 95% CI 0.44 to 0.82, NNT = 9, 95% CI 6 to 24, 4 RCTs, 764 participants).

AUTHORS' CONCLUSIONS

The present study detected differences in terms of efficacy and tolerability between fluoxetine and certain ADs, but the clinical meaning of these differences is uncertain.Moreover, the assessment of quality with the risk of bias tool showed that the great majority of included studies failed to report details on methodological procedures. Of consequence, no definitive implications can be drawn from the studies' results. The better efficacy profile of sertraline and venlafaxine (and possibly other ADs) over fluoxetine may be clinically meaningful,as already suggested by other systematic reviews. In addition to efficacy data, treatment decisions should also be based on considerations of drug toxicity, patient acceptability and cost.

Response prediction to antidepressants using scalp and source-localized loudness dependence of auditory evoked potential (LDAEP) slopes

The loudness-dependence of the auditory evoked potential (LDAEP) slope may be inversely related to serotonin (5-HT) neurotransmission. Thus, steep LDAEPs tend to predict a positive response to selective serotonin reuptake inhibitor (SSRI) antidepressants, which augment 5-HT. However, LDAEPs also predict outcome to antidepressants indirectly altering 5-HT (e.g. bupropion). Hence, the LDAEP's predicative specificity and sensitivity to antidepressant response/outcome remains elusive. Scalp N1, P2 and N1/P2 LDAEP slopes and standardized low resolution brain electromagnetic tomography (sLORETA)-localized N1 and P2 LDAEP slopes were assessed in depressed individuals (N=51) at baseline, 1 and 12 weeks post-treatment with one of three antidepressant regimens [escitalopram (ESC)+bupropion (BUP), ESC or BUP]. Clinical response was greatest with ESC+BUP at week 1. Treatment responders had steep N1 sLORETA-LDAEP baseline slopes while non-responders had shallow ones. P2 sLORETA-LDAEP slope increases at 1 week existed in responders; decreases were noted in non-responders. Exploratory analyses indicated that more BUP and ESC responders versus non-responders had steep baseline N1 sLORETA-LDAEP slopes. Additionally, slight decreases in scalp P2 LDAEP by week 1 existed for ESC treatment, while slope increases existed with ESC+BUP treatment. Only baseline N1 sLORETA-LDAEP discriminated treatment responders/non-responders. This work confirms that certain LDAEP measures are associated with treatment outcome and appear to be differentially modulated with varying antidepressant drug regimens, though this should be confirmed using larger samples.

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.

Multi-modality: a new approach for the treatment of major depressive disorder

Effective treatment with antidepressants is currently limited by factors that affect treatment compliance, including delay in onset of therapeutic effects and intolerable side-effects. Recent data suggest that use of antidepressant combinations with different mechanisms of action may be a better first-line strategy prior to augmentation with other drug classes. The rationale for this approach is that combining multiple pharmacological actions affecting multiple monoamine targets produces greater efficacy. Several new multi-modal compounds are in development and early results for the most advanced agents indicate shorter onset of therapeutic effects and improved tolerability. By modulating multiple receptors and transmitter systems, it is hoped that these new agents may also treat some of the associated symptoms of major depressive disorder, such as anxiety and cognitive dysfunction.

Tianeptine combination for partial or non-response to selective serotonin re-uptake inhibitor monotherapy

AIMS

The goal of this study was to assess the efficacy and tolerability of tianeptine in combination with selective serotonin re-uptake inhibitor (SSRI) in partial responders or non-responders to SSRI monotherapy.

METHODS

In this prospective, open-label, 6-week study, 150 patients with major depressive disorder who had previously not responded or partially responded to SSRI monotherapy were recruited. Tianeptine was given in combination with an SSRI for 6 weeks.

RESULTS

Significant improvements were observed in the mean scores of the Hamilton Depression Rating Scale (HDRS), Montgomery-Åsberg Depression Rating Scale (MADRS), and Clinical Global Impression-Severity (CGI-S). The change in the mean HDRS, MADRS, and CGI-S scores was significant from week 1. The response rates were 64.7% (HDRS) and 68.7% (MADRS), and the remission rates were 34.0% (HDRS) and 42.0% (MADRS) at week 6. Thirty-six patients (24.0%) reported adverse events that were determined by the investigator to be related to one of the study drugs. The tianeptine and SSRI combination was generally well-tolerated.

CONCLUSIONS

A combination strategy with tianeptine may be an effective and well-tolerated tool for patients who have failed to adequately respond to SSRI monotherapy.

Serotonin and beyond: therapeutics for major depression

The serotonin (5-HT, 5-hydroxytryptamine) system has been implicated in the pathogenesis of major depressive disorder (MDD). The case for its contribution to the therapeutic efficacy of a wide variety of antidepressant treatments is, however, much stronger. All antidepressant strategies have been shown to enhance 5-HT transmission in the brain of laboratory animals. Catecholamines, norepinephrine (NE) and dopamine (DA) can also play a pivotal role in the mechanism of action of certain antidepressant strategies. The enhancement of 5-HT transmission by selective serotonin reuptake inhibitors, which leads to a dampening of the activity of NE and DA neurons, may account in part for the low remission rate achieved with these medications and/or the residuals symptoms after remission is achieved. The functional connectivity between the 5-HT, NE and DA systems can be used to understand the mechanism of action of a wide variety of augmentation strategies in treatment-resistant MDD. Proof-of-concept studies have shown that antidepressant medications with complementary mechanisms of action on monoaminergic systems can double the remission rate achieved in a trial of standard duration. Novel approaches are also being used to treat MDD, which also appear to involve the monoaminergic system(s) to a varying extent.

Antidepressant monotherapy compared with combinations of antidepressants in the treatment of resistant depressive patients: a randomized, open-label study

OBJECTIVE

This randomized, 6-week, open-label study compared efficacy of CAD and antidepressant monotherapies (ADM) that had been chosen according to clinical judgment of the attending psychiatrist.

METHODS

A total of 60 inpatients (intent-to-treat analysis) with depressive disorder (≥ 1 unsuccessful antidepressant treatment) were randomly assigned to the interventions. The responders who completed the acute phase of study, were evaluated for relapse within 2 months of follow-up treatment. The primary outcome measure was change in the Montgomery-Åsberg Depression Rating Scale (MADRS) and response was defined as a ≥ 50% reduction of MADRS score.

RESULTS

Mean changes in total MADRS score from baseline to week 6 for patients in both treatment modalities were not different (ADM = 13.2 ± 8.6 points; CAD = 14.5 ± 9.5 points; P = 0.58). The analysis of covariance performed for significantly higher value of imipramine equivalent dose in CAD group showed only a non-significant between-group difference for total MADRS change (P = 0.17). There were also no differences between groups in response rate (ADM = 48%; CAD = 58%) and number of drop-outs in acute treatment as well as proportion of responders' relapses in the follow-up.

CONCLUSION

Both treatment modalities produced clinically relevant reduction of depressive symptomatology in acute treatment of patients with resistant depression and their effect was comparable.

Antidepressive-Like Property of Dichloromethane Fraction of Pimenta pseudocaryophyllus and Relevance of Monoamine Metabolic Enzymes

Pimenta pseudocaryophyllus popularly referred to as craveiro is considered as a calming agent in different local preparations. The present study attempted to examine antidepressant-like effect of dichloromethane fraction (DF) and role of monoamine oxidase (MAO), tryptophan, and tyrosine hydroxylase. Based on the research focus, tail suspension (TS), forced swimming (FS), and open field (OF) tests were conducted after oral administration of DF (125, 250, or 500 mg/Kg). Ex vivo assay of MAO was also conducted to evaluate inhibitory effect of DF (250 mg/Kg). Administration of DF elicits antidepressant-like response in the TS and FS. However, DF 500 mg/Kg did not alter mice performance in these models. The data obtained in the OF showed a reduction in total crossing and rearing activity; these effects suggest motor interference in TS and FS performance. Mice pretreatment with p-chlorophenylalanine methyl ester (PCPA) (100 mg/kg, i.p.—serotonin biosynthesis inhibitor) for 4 consecutive days or acute administration of α-methyl-p-tyrosine (AMPT) (100 mg/kg, i.p.—catecholamine synthesis inhibitor) blocked anti-immobility effect of DF in the FS. In ex vivo assay of MAO, DF did not inhibit catabolic activity of MAO. Our findings support antidepressant-like activity of DF and suggest an effect that depends on monoamine biosynthesis.

Pioglitazone adjunctive therapy for moderate-to-severe major depressive disorder: randomized double-blind placebo-controlled trial

Thiazolidinediones have shown antidepressant effect in animal studies, as well as in some uncontrolled studies evaluating human subjects with concurrent major depressive disorder (MDD) and metabolic syndrome. Although these drugs are insulin sensitizers, they also have important anti-inflammatory, neuroprotective, and anti-excitotoxic properties. Thus, we hypothesized that they would show antidepressant effect in patients with MDD even if it was not accompanied by metabolic disturbances. In this double-blind placebo-controlled study, 40 patients with MDD (DSM-IV-TR) and Hamilton depression rating scale-17 (Ham-D) score ≥ 22 were randomized to citalopram plus pioglitazone (15 mg every 12 h) (n=20) or citalopram plus placebo (n=20) for 6 weeks. Patients were evaluated using Ham-D (weeks 0, 2, 4, 6). Repeated-measure analysis of variance (ANOVA) and analysis of covariance were used for comparison of scores between the two groups. Treatment response (≥ 50% reduction in Ham-D score), remission (Ham-D score ≤ 7), and early improvement (≥ 20% reduction in Ham-D score within the first 2 weeks) were compared between the two groups using Fisher's exact test. Pioglitazone showed superiority over placebo during the course of the trial (F(1, 38)=9.483, p=0.004). Patients in the pioglitazone group had significantly lower scores at all time points than the placebo group (P<0.01). Frequency of early improvement, response (week 6), and remission was significantly higher in the pioglitazone group (95%, 95%, 45%, respectively) than in the placebo (30%, 40%, 15% respectively) group (P<0.001, <0.001, 0.04, respectively). Frequency of side effects was similar between the two groups. Pioglitazone is a safe and effective adjunctive short-term treatment in patients with moderate-to-severe MDD even in the absence of metabolic syndrome and diabetes.

Do we need more than one antidepressant for patients with major depressive disorder?

According to currently existing treatment guidelines, when a single antidepressant medication is not working, the common next step treatment is to switch to another class of antidepressants or to add another one to the first therapeutic agent. With regard to this issue, combination therapy has been suggested to provide unexpected synergy for patients, resulting in more remission compared with switching strategies, although some debates are still ongoing. Recently, Rush and colleagues have investigated whether two antidepressant combination treatments should produce a higher remission rate in first-step acute-phase (12 weeks) and long-term (7 months) treatment compared with monotherpay. They failed to find any superiority of combination treatment over monotherapy in terms of efficacy and safety. The remission and response rates and most secondary outcomes were not different among treatment groups at 12 weeks and 7 months, while the mean number of worsening adverse events was higher for combination treatment (5.7) than for monotherapy (4.7) at 12 weeks. This article will discuss the clinical and further research implications in the context of the potential limitations and significance of this recent study.

Targeting Treatment-Resistant Depression

Only 50% of depressed patients achieve remission of symptoms after 2 trials of antidepressants. Therefore one half of patients are considered treatment resistant. Studies have shown that with each failed antidepressant, chances of remission continue to decline. Untreated depressive symptoms lead to impaired social and occupational function, decline of physical health, suicidal thoughts, and increased health care utilization. Clinicians recognize there is an urgent need to find an efficacious treatment, but it becomes more difficult to decide on an appropriate therapy once a patient has failed 2 to 3 trials of antidepressants. An evidence-based review was performed to assess the efficacy and safety of several different antidepressant strategies to help the clinician decide which may be beneficial for specific patients.

Use of treatment algorithms for depression

Depression continues to be a treatment challenge for many physicians-psychiatrists and primary care physicians alike-in part because of the nature of the disorder, but also because of the wide variety of medications and other treatments available, each with a distinct efficacy and safety profile. One way of negotiating treatment decisions is to use treatment guidelines and algorithms. This Commentary, which appears in the September 2006 issue of The Journal of Clinical Psychiatry (2006;67:1458-1465), provides the primary care clinician with insight into the pros and cons of using treatment algorithms to guide the treatment of depression. -Larry Culpepper, M.D.

The safety and tolerability of duloxetine compared with paroxetine and placebo: a pooled analysis of 4 clinical trials

BACKGROUND

To compare the safety and tolerability of duloxetine with paroxetine and placebo in patients with major depressive disorder (MDD).

METHOD

Data from four 8-week randomized, double-blind, placebo- and paroxetine-controlled studies of duloxetine for MDD (DSM-IV criteria) were pooled to compare the safety and tolerability of duloxetine 40 to 120 mg/day with paroxetine 20 mg q.d. Two of the 4 trials included a 26-week extension.

RESULTS

The pooled database included 1466 patients (duloxetine, N = 736; paroxetine, N = 359; placebo, N = 371). No deaths occurred in the acute phase trials. Discontinuation rates for adverse events did not differ significantly for duloxetine, 8.0%, and paroxetine, 6.1%. Nausea was the most frequent treatment-emergent adverse event for duloxetine (duloxetine, 14.4%; paroxetine, 12.0%; placebo, 3.8%). Blood pressure and corrected QT (QTc) interval changes were modest and did not differ significantly for the 3 groups. Mean heart rate increased slightly in the duloxetine group, 1.0 beat/minute, and did differ significantly (p < .001) from that in the paroxetine group, but the change is of doubtful importance. Mean changes in laboratory analytes remained within the reference range. Emergent sexual dysfunction was significantly greater among duloxetine- and paroxetine-treated patients than placebo-treated patients (p = .007 vs. duloxetine and p < .001 vs. paroxetine); however, it was significantly lower in duloxetine-treated patients than in paroxetine-treated patients (46.4% vs. 61.4%; p = .015). During the extension phase, weight gain (≥ 7% of initial body weight) was greater in both active-treatment groups than in the placebo group (duloxetine, 10.8%; paroxetine, 13.8%; placebo, 3.1%), but the active-treatment groups did not differ.

CONCLUSIONS

Duloxetine is safe and well tolerated in patients with MDD, with safety and tolerability comparable to that of paroxetine.

Therapeutic options in treatment-resistant depression

The phenomenon of treatment-resistant depression (TRD), described as the occurrence of an inadequate response after an adequate treatment with antidepressant agents (in terms of dose, duration, and adherence), is very common in clinical practice. It has been broadly defined in the context of unipolar major depression, but alternative definitions for bipolar depression have also been suggested. In both cases, there is a remarkable lack of consensus amongst professionals concerning its operative definition. A relatively wide variety of treatment options for unipolar TRD are available, whilst the evidence is very scanty for bipolar TRD. TRD is associated to poor clinical, functional, and social outcomes. Several novel therapeutic options are currently being investigated as promising alternatives, targeting the neurotransmitter system outside of the standard monoamine hypothesis. Augmentation or combination with lithium or atypical antipsychotics appears as a valid option for both conditions, and the same occurs with electroconvulsive therapy. Other non-pharmacological strategies such as deep brain stimulation may be promising alternatives for the future. The use of cognitive behaviour therapy is recommended for unipolar TRD, but there is no evidence supporting its use in bipolar TRD.

Antidepressant combinations: widely used, but far from empirically validated

This paper reviews the evidence on combining antidepressants (ADs) for treatment of major depressive disorder. Although widely used and usually safe, the efficacy of even the most widely prescribed combinations of ADs has not been established by properly controlled, adequately powered, clinical trials. This stands in contrast to several adjunctive strategies for AD nonresponders, including adjunctive lithium, thyroid hormone, or newer-generation antipsychotics. The wide use of AD combinations no doubt reflects the limited efficacy of commonly used ADs and the unmet need for effective strategies for patients with treatment-resistant depression. Although of unproven efficacy, potential merits of combining selected ADs include: (1) avoiding discontinuation-emergent symptoms and cross-titration schedules, (2) at worst, the second AD should be as effective in combination as it would be as a monotherapy following a switch, and (3) the possibility of complementary neuropharmacologic effects that may enhance efficacy or improve tolerability. The dearth of controlled studies of such a commonly used strategy for such a highly prevalent condition is symptomatic of shortcomings in the way clinically relevant research is funded, points to the need for industry-academic-federal collaborations, and underscores the need for large, practice-based, research groups that can efficiently complete publicly funded studies of high public health impact.

If at first you don't succeed: a review of the evidence for antidepressant augmentation, combination and switching strategies

Major depressive disorder is a common and disabling illness that leads to significant reductions in quality of life and considerable cost to society. Despite numerous advances in the pharmacological treatment of depression, many patients remain ill despite initial treatment. Beyond first-line treatment, current guidelines recommend either augmentation or switching of the initial antidepressant. In this narrative review, we summarize the data from randomized controlled trials and meta-analyses in order to concisely discuss how the impact of current research can be translated into clinical practice and, ultimately, into lasting improvements in patient outcomes. The augmentation strategies reviewed are lithium, thyroid hormone, pindolol, psychostimulants and second-generation antipsychotics. The data on switching from first-line antidepressants to other antidepressants are also reviewed, and include switching within the same class, switching to other first-line antidepressant classes and switching to less commonly prescribed antidepressants. Finally, the strategy of antidepressant combinations is examined. Overall, the strength of evidence supporting a trial of augmentation or a switch to a new agent is very similar, with remission rates between 25% and 50% in both cases. Our review of the evidence suggests several conclusions. First, although it is true that adjunctive lithium and thyroid hormone have established efficacy, we can only be confident that this is true for use in combination with tricyclic antidepressants (TCAs), and the trials were done in less treatment-resistant patients than those who typically receive TCAs today. Of these two options, triiodothyronine augmentation seems to offer the best benefit/risk ratio for augmentation of modern antidepressants. After failure of a first-line selective serotonin reuptake inhibitor (SSRI), neither a switch within class nor a switch to a different class of antidepressant is unequivocally supported by the data, although switching from an SSRI to venlafaxine or mirtazapine may potentially offer greater benefits. Interestingly, switching from a newer antidepressant to a TCA after a poor response to the former is not supported by strong evidence. Of all strategies to augment response to new-generation antidepressants, quetiapine and aripiprazole are best supported by the evidence, although neither the cost effectiveness nor the longer-term benefit of these strategies has been established. The data to guide later steps in the treatment of resistant depression are sparse. Given the wide variety of options for the treatment of major depressive disorder, and the demonstrated importance of truly adequate treatment to the long-term outcomes of patients facing this illness, it is clear that further well conducted studies are needed.