Delayed onset of action of antidepressant drugs? Survey of results of Zurich meta-analyses

Influence of eight ABCB1 polymorphisms on antidepressant response in a prospective cohort of treatment-free Russian patients with moderate or severe depression: An explorative psychopharmacological study with naturalistic design

BACKGROUND

Many antidepressants are substrates of P-glycoprotein, an efflux transporter in the blood-brain-barrier encoded by the ABCB1 gene. Genetic variations might influence the transport rate of antidepressants and hence their pharmacological effects. This study investigates the influence of eight polymorphisms in the ABCB1 gene on antidepressant treatment response.

METHOD

152 patients were included from psychiatric departments of the Mental Health Research Institute in Tomsk. The difference in Hamilton-Depression-Rating-Scale (HAMD-17)-scores between baseline and week two, week two and four, and baseline and week four was used to estimate timing of improvement of depression. Associations between the ABCB1 gene-polymorphisms and reduction in HAMD-17 score were assessed using independent t-test and multiple linear regression.

RESULTS

Tricyclic antidepressants were associated with a higher reduction of HAMD-17 score when compared to SSRIs. The SNP rs2235040 A-allele had a significant positive influence on the ΔHAMD-17_(0→2W) score but a significant negative influence on the ΔHAMD-17_(2→4W) score. The rs4148739 G-allele had a significant negative influence on the ΔHAMD-17_(0→2W) score but a significant positive influence on the ΔHAMD-17_(2→4W) score. The SNP rs2235015 T-allele is significant negatively related to the ΔHAMD-17_(2→4W) score.

CONCLUSION

ABCB1 Genetic variations appear to affect speed but not magnitude of antidepressant drug response.

Early symptomatic improvements as a predictor of response to repeated-dose intravenous ketamine: Results from the Canadian Rapid Treatment Center of Excellence

BACKGROUND

Early symptomatic improvement with monoamine-based antidepressants is predictive of treatment response. The objective of this study was to determine if early symptomatic improvements with intravenous (IV) ketamine predicted treatment response to an acute course of four infusions.

METHOD

134 adults with treatment resistant depression (TRD) received four ketamine infusions over one to two weeks. Depressive symptoms were measured using the Quick Inventory for Depressive Symptomatology Self-Report₁₆ (QIDS-SR₁₆) at baseline and post-infusions 1, 2, 3, and 4. Early improvement was defined as ≥20% reduction in QIDS-SR₁₆ scores after the first or second infusion. Linear models were used to determine whether early improvement was associated with post-infusion 4 QIDS-SR₁₆ scores after controlling for baseline characteristics.

RESULTS

Early improvement post-infusion 1 (β = -3.52, 95% BCa CI [-5.40, -1.78]) and 2 (β = -3.16, 95% BCa CI [-5.75, -1.59]) both significantly predicted QIDS-SR₁₆ scores post-infusion 4. Early improvers had significantly lower QIDS-SR₁₆ scores at post-infusion 4 (post-infusion 1 improvers: M = 9.8, SD = 4.5; post-infusion 2 improvers: M = 10.6, SD = 5.7) compared to non-early improvers (post-infusion 1 non-improvers: M = 13.7, SD = 5.8; post-infusion 2 non-improvers: M = 14.1, SD = 5.3) when controlling for baseline characteristics. The majority (58%) of individuals who did not improve post-infusions 1 or 2 still experienced an antidepressant response or partial response (≥20% reduction in QIDS-SR₁₆) post-infusion 4.

LIMITATIONS

This is a post-hoc analysis of an open-label study.

CONCLUSION

Early improvement was associated with greater antidepressant effects following a course of four ketamine infusions. However, individuals who did not show early improvements still had a high likelihood of experiencing clinically significant symptom reduction after the fourth infusion, suggesting that completing four infusions, regardless of early symptom changes, is appropriate and merited.

Onset of action under antidepressant treatment

The issues of timing in antidepressant treatment are of great theoretical and practical relevance, even more so since recent meta-analyses yielded no evidence for a specific mode of action of antidepressants, which, according to the theory of delayed onset of action, is expected to emerge after 2 weeks of therapy. To address the issues of timing on a methodologically sound basis, future trials should adapt a ‘longitudinal’ rather than ‘cross-sectional’ design, standardized with respect to a washout period, baseline and first 2 week assessments. With this in mind, special attention should be paid to parameters which potentially enable the identification of placebo responders, true drug responders and patients at risk of non-improvement. Results and methods of the Zurich meta-analyses may serve as a starting point for further steps in this direction.

Onset of improvement under fluoxetine and moclobemide

In a meta-analysis of the selective serotonin reuptake inhibitor fluoxetine (n = 440) and the reversible and selective monoamine oxidase-A inhibitor moclobemide (n = 437) we investigated the time course of improvement over 6 weeks for these two classes of anti-depressants. Two different methods of approach were applied: (1) repeated measurement analysis of variance in combination with regression analysis, and (2) a survival-analytical approach that allowed us to determine onset of improvement for the individual patient, to distinguish between early and late improvers, to assess the predictive value of early improvement, and to adequately process premature withdrawals. The two antidepressants of large biochemical and pharmacological differences yielded virtually identical response- and drop-out rates, and exhibited no difference with respect to the time course of improvement. Onset of improvement occurred in more than half of the patients within the first 2 weeks of treatment, and early improvement was highly predictive of later outcome. In particular, there was no indication for a delayed onset of action of antidepressants. We suggest that future studies should be standardised with respect to washout period and sufficiently dense assessments during the first 2 weeks of trial. Thus, patient samples can be subdivided reproducibly into early-, late-, partial- and non-remitters. This, in turn, may help to identify “true” drug responders, and to discover why in some patients recovery becomes “stuck”. Data already held by the pharmaceutical companies should be reanalysed in this respect.

Neurochemical and behavioural effects of hypidone hydrochloride (YL-0919): a novel combined selective 5-HT reuptake inhibitor and partial 5-HT1A agonist

BACKGROUND AND PURPOSE

Our previous studies revealed that hypidone hydrochloride (YL-0919), which acts as a selective 5-HT (serotonin) reuptake inhibitor (SSRI) and displays partial 5-HT_1A receptor agonist properties, exerts a significant antidepressant effect in various animal models. The aim of present research was to further investigate the pharmacology of YL-0919.

EXPERIMENTAL APPROACH

We first investigated the target profile of YL-0919 using [³⁵ S]-GTPγS binding and microdialysis. To determine whether the 5-HT or noradrenergic systems are involved in the antidepressant-like effect of YL-0919, the 5-hydroxytryptophan (5-HTP)-induced head-twitch test and antagonism with a high dose of apomorphine were performed. Using the learned helplessness paradigm, the novelty suppressed feeding test, the Vogel-type conflict and elevated plus-maze test, we further verified the antidepressant-like and anxiolytic-like effects of YL-0919. The effects of YL-0919 on hippocampal long-term potentiation (LTP) and sexual behaviour were also evaluated.

KEY RESULTS

Data from the present study demonstrated that YL-0919 displays partial 5-HT_1A receptor agonist properties, producing a greater impact on extracellular 5-HT levels than a conventional SSRI (fluoxetine), as well as significant antidepressant and anxiolytic effects. Furthermore, YL-0919 treatment rapidly influenced the synaptic plasticity (enhancing LTP) of rats. Finally, at doses close to those producing antidepressant-like effects, YL-0919 did not result in a marked inhibition of sexual function.

CONCLUSIONS AND IMPLICATIONS

These data suggest that YL-0919 is probably a fast-onset potent antidepressant with few side effects.

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.

Hamilton depression rating subscales to predict antidepressant treatment outcome in the early course of treatment

BACKGROUND

Hamilton depression rating scale (HAMD) subscales provide an economic alternative for the full scale; however, their ability to detect onset of improvement in the early course of treatment (EI) has not yet been researched. The present study investigated in patients with major depression (MD) whether the subscales are a comparable option to predict treatment remission in the early course of treatment.

METHODS

Based on data from 210 MD patients of a 6-week randomised, placebo-controlled trial comparing mirtazapine (MIR) and paroxetine (PAR), the discriminative and predictive validity of EI for (stable) remission at treatment end was evaluated for seven subscales and the HAMD17 in the total and in treatment subgroups (MIR vs. PAR). Receiver operating characteristics (ROC) curves (at week 2) and the Clinical Global Impression scales (CGI) (at study endpoint) were used to validate the 20% EI criterion for the subscales.

RESULTS

Only the Evans6 and Toronto7 subscale had almost the same predictive value as the HAMD17 (e.g., sensitivities stable remission Evans6/Toronto7: 96/95% vs. 96% HAMD17). The optimal cut-off for EI to predict remission was just below 20% for most subscales and slightly over 20% for stable remission.

LIMITATIONS

Study sample representativeness, non-independence of subscales, missing external validation criterion, lack of control group.

CONCLUSIONS

The Evans6 and Toronto7 subscales are valuable alternatives in situations, where economic aspects play a larger role. A sum score reduction of ≥20% as definition for EI seems also appropriate for the HAMD subscales, in the total as well as in the antidepressant subgroups.

Early improvement as a predictor of eventual antidepressant treatment response in severely depressed inpatients

RATIONALE

Traditionally, the therapeutic effect of antidepressants is thought to take several weeks. However, several studies found evidence of early drug response occurring within the first 2 weeks of antidepressant treatment and that this early onset response may predict eventual treatment outcome.

OBJECTIVE

This study aims to investigate the predictive value of early improvement in the course of treatment with imipramine or venlafaxine in an inpatient population with severe major depression.

METHOD

A post hoc analysis was conducted after pooling data from two almost identical trials. The study included 149 patients with DSM-IV diagnosis major depression and a baseline score ≥17 on the 17-item Hamilton Rating Scale for Depression (HAM-D). Patients were randomized for double-blind treatment with either antidepressant. Early improvement (≥25 % reduction on HAM-D score) was evaluated after 2 weeks and response (≥50 % reduction on HAM-D score) after 6 weeks of acute treatment.

RESULTS

Of 64 patients achieving early improvement, 38 (59 %) became responders, whereas of 85 patients not achieving early improvement, only 23 (27 %) became responders. There was a significant difference in time to response between patients achieving early improvement and patients not achieving early improvement. Early improvement is a modest sensitive predictor for eventual response.

CONCLUSION

In the present study, although the sensitivity of early improvement was modest, based on the severity of clinical symptoms, a clinician treating a patient with severe major depression may seriously consider changing the treatment at an earlier stage than is presently customary.

High baseline BDNF serum levels and early psychopathological improvement are predictive of treatment outcome in major depression

RATIONALE

Major depressive disorder has been associated with low serum levels of brain-derived neurotrophic factor (sBDNF), which is functionally involved in neuroplasticity. Although sBDNF levels tend to normalize following psychopathological improvement with antidepressant treatment, it is unclear how closely sBDNF changes are associated with treatment outcome.

OBJECTIVES

To examine whether baseline sBDNF or early changes in sBDNF are predictive of response to therapy.

METHODS

Twenty-five patients with major depressive disorder underwent standardized treatment with duloxetine. Severity of depression, measured by the Hamilton Depression Rating Scale, and sBDNF were assessed at baseline, and after 1, 2, and 6 weeks of treatment. Therapy outcome after 6 weeks was defined as response (≥50 % reduction in baseline Hamilton Depression Rating score) and remission (Hamilton Depression Rating score <8). The predictive values for treatment outcome of baseline sBDNF, and early (i.e., ≤2 weeks) changes in sBDNF and Hamilton Depression Rating score were also assessed.

RESULTS

At baseline, sBDNF correlated with Hamilton Depression Rating scores. Treatment response was associated with a higher baseline sBDNF concentration, and a greater Hamilton Depression Rating score reduction after 1 and 2 weeks. A greater early rise in sBDNF correlated with a decreased early Hamilton Depression Rating score reduction.

CONCLUSIONS

Even though higher baseline sBDNF levels are associated with more severe depression, they may reflect an increased capacity to respond to treatment. In contrast, changes in sBDNF over the full course of treatment are not associated with psychopathological improvement.

Differential Effects of Single-Dose Escitalopram on Cognitive and Affective Interference during Stroop Task

BACKGROUND AND OBJECTIVE

Our aim was to study the regulatory role of serotonin [(5-hydroxytryptamine (5-HT)] on two key nodes in the cognitive control networks - the anterior cingulate cortex (ACC) and the dorsolateral prefrontal cortex (DLPFC). We hypothesized that increasing the levels of 5-HT would preferentially modulate the activity in ACC during cognitive control during interference by negative affects compared to cognitive control during interference by a superimposed cognitive task.

METHODS

We performed a functional magnetic resonance imaging investigation on 11 healthy individuals, comparing the effects of the selective 5-HT reuptake inhibitor escitalopram on brain oxygenation level dependent signals in the ACC and the DLPFC using affective and cognitive counting Stroop paradigms (aStroop and cStroop).

RESULTS

Escitalopram significantly decreased the activity in rostral ACC during aStroop compared to cStroop (p < 0.05). In the absence of escitalopram, both aStroop and cStroop significantly activated ACC and DLPFC (Z ≥ 2.3, p < 0.05).

CONCLUSION

We conclude that escitalopram in a region and task specific manner modified the cognitive control networks and preferentially decreased activity induced by affective interference in the ACC.

A benzodiazepine impairs the neurogenic and behavioural effects of fluoxetine in a rodent model of chronic stress

Antidepressant agents such as fluoxetine have been shown to produce neurogenic effects involving transcriptional and translational changes that direct molecular and cellular plasticity. These cellular and molecular events appear necessary to mediate the therapeutic effects of fluoxetine and may be generated through the ability for fluoxetine to regulate BDNF levels. Clinically, benzodiazepines are frequently used in combination with standard antidepressants both for initial treatment and maintenance therapy, especially when comorbid anxiety is present. However, very little is known regarding the consequence of combined treatment of benzodiazepines and antidepressant on the development of clinical effect. The current study therefore examined the effect of co-administration of fluoxetine and the benzodiazepine, diazepam, on hippocampal neurogenesis in the social isolation rodent model of chronic stress. We demonstrate that 9 weeks of social isolation induces a deficit in motivational behaviour with increased anxiety as well as impairment in hippocampal neurogenesis. This was parallelled by reduced BDNF levels in the hippocampus. While treatment with fluoxetine alone for 3 weeks restored anxiety behaviour as well as progenitor cell proliferation and the generation of new hippocampal neurons, this effect was prevented by co-administration with diazepam. This suggests that co-administering benzodiazepines with antidepressants could significantly delay or prevent the cellular and behavioural improvement needed by patients. These findings indicate the need for future clinical studies designed to investigate the combined effects of benzodiazepines and antidepressants in patients.

Early improvement with lithium in classic mania and its association with later response

OBJECTIVES

Despite lithium's clinical efficacy in treating mania in bipolar disorder (BD), studies evaluating early improvement and subsequent treatment response are sparse. This study investigated whether early improvement (within one week) to lithium monotherapy predicted later response and remission in individuals with BD mania.

METHODS

BD-I patients (n=46) experiencing a manic episode received lithium monotherapy for four weeks (initial dose: 600mg/d, adjusted to therapeutic levels); individuals experiencing a mixed episode, rapid cyclers, previous non-responders to lithium, and those with current drug abuse/dependence were excluded. Symptoms were rated using the Young Mania Rating Scale (YMRS) at baseline and at Days 7, 14, 21, and 28.

RESULTS

Thirty-three percent of the total sample responded to lithium within the first week of treatment, defined as a ≥50% decrease from baseline YMRS scores; 63% responded by study endpoint. In addition, 39% of the total sample showed early improvement (at least 20% decrease in YMRS scores) after one week of treatment. In this group, 79% responded to lithium by study endpoint. Among those showing less than 20% improvement at Week 1, only 23% responded to lithium by study endpoint.

LIMITATIONS

History of episodes sequence was not assessed.

CONCLUSIONS

Early improvement in response to lithium monotherapy in subjects with BD mania predicted later response and remission. Most patients who did not show early improvement in response to lithium during the first week of treatment showed no response after one month. The findings provide a valuable clinical tool for early identification of those patients most likely to benefit from lithium in clinical practice.

Early predictors of two month response with mianserin and selective serotonin reuptake inhibitors and influence of definition of outcome on prediction

In order to identify clinical and demographic variables that predict response to antidepressants and to analyse prediction of outcome as a function of definition of outcome we analysed pooled data of two independent, multicentre, double blind parallel group studies. Study I compared the efficacy of mianserin with that of fluoxetine in 65, and study II compared mianserin with fluvoxamine in 60 patients with depression. Improvement was defined as at least 20% decrease in MADRS by day 14. Patients were considered as responders if they had greater than 50% decrease and non-responders if they had </= 50% decrease from baseline in the MADRS at day 56. Complete remission was defined as MADRS score </= 6 at day 56. Patients' characteristics did not differ between mianserin and SSRI groups. Early improvement predicted response in 92% and complete remission in 55% of the patients improved at day 14. Multivariate forward stepwise logistic regression analysis showed that response to treatments at day 56 was significantly (P = 0.0003) associated with early improvement, age (responders had higher age than non-responders) and weight (responders weighted more than non-responders). Complete remission was only predicted by early improvement. Treatments could not be differentiated when data were analysed according to responder/nonresponder status or complete remission/no complete remission. However, when the same data were analysed by analysis of variance a significant treatment effect (P = 0.02, mianserin > SSRIs) and a quadratic type treatment by time interaction (P = 0.023) were found. The robustness of the analysis was further improved by inclusion of covariates (age, weight). Early clinical improvement seems to be the best predictor of 2 month response to antidepressants (mianserin, SSRIs). Younger age and lower weight may predict non-response. Quantitative analysis differentiates treatments better than analysis of responder status. As obtenation of complete remission is a realistic objective with current antidepressants, studies longer than 2 months are needed to assess effectiveness of these drugs in the obtenation of complete remission.

Surrogate markers of treatment outcome in major depressive disorder

Major depressive disorder (MDD) is a common medical illness affecting millions worldwide. Despite their widespread use since the 1950s and 1960s, the 'downstream' mechanism by which antidepressants ultimately exert their therapeutic effects remains elusive. In addition, except for a few exceptions such as episode severity and the presence of comorbid Axis-I or Axis-III disorders, biological or clinical characteristics which can accurately quantify the risk of poor treatment outcome are lacking, as are factors which could help patients and clinicians select treatment options that would result in superior outcome. The identification of such markers, termed 'surrogate' markers, could help shed further insights into what constitutes illness and recovery, help identify molecular targets for the development of future antidepressants, and lead the way to the design and refinement of a personalized medicine treatment model for MDD. In the following text, several major areas ('leads') where evidence exists regarding the presence of surrogate markers of efficacy outcome in MDD will be briefly reviewed. Leads include evidence from the role of demographic and clinical factors as surrogate markers, to the role of various biological markers including genotype, brain functional imaging, electroencephalography, dichotic listening, and molecular biology and immunology. The purpose of this work is to focus selectively on areas where there have been findings, as opposed to conducting an exhaustive literature review of studies which have failed to yield any significant breakthrough in our knowledge.

The early improvement of depressive symptoms as a potential predictor of response to antidepressants in depressive patients who failed to respond to previous antidepressant treatments. Analysis of naturalistic data

INTRODUCTION

Current studies suggest that improvement of depressive symptoms after 2 weeks of treatment could predict the subsequent response. The aim of our study was to compare the predictive effect of early improvement (EI) after 1 and 2 weeks of treatment in patients who had failed to respond to previous antidepressant treatments (≥1 unsuccessful antidepressant trial).

METHOD

Seventy-one subjects were treated (≥4 weeks) with various antidepressants chosen according to the judgment of attending psychiatrists. We used three definitions of EI (MADRS reduction ≥20, 25, 30%) at both time points. Areas under curve (AUC) were calculated to compare predictive effect of EI.

RESULTS

We found lower MADRS scores in weeks 1 and 2 in responders (≥50% reduction of MADRS, n=35) compared to nonresponders. AUCs of MADRS reduction for response prediction at week 1 and 2 were not significantly different (0.73 vs 0.8; p=0.24).

CONCLUSION

The results indicate that improvement of depressive symptoms in the treatment of resistant patients may occur after the first week of treatment. The predictive potential might be comparable to that found after the second week of antidepressant intervention and be clinically meaningful.

General and comparative efficacy and effectiveness of antidepressants in the acute treatment of depressive disorders: a report by the WPA section of pharmacopsychiatry

Current gold standard approaches to the treatment of depression include pharmacotherapeutic and psychotherapeutic interventions with social support. Due to current controversies concerning the efficacy of antidepressants in randomized controlled trials, the generalizability of study findings to wider clinical practice and the increasing importance of socioeconomic considerations, it seems timely to address the uncertainty of concerned patients and relatives, and their treating psychiatrists and general practitioners. We therefore discuss both the efficacy and clinical effectiveness of antidepressants in the treatment of depressive disorders. We explain and clarify useful measures for assessing clinically meaningful antidepressant treatment effects and the types of studies that are useful for addressing uncertainties. This includes considerations of methodological issues in randomized controlled studies, meta-analyses, and effectiveness studies. Furthermore, we summarize the differential efficacy and effectiveness of antidepressants with distinct pharmacodynamic properties, and differences between studies using antidepressants and/or psychotherapy. We also address the differential effectiveness of antidepressant drugs with differing modes of action and in varying subtypes of depressive disorder. After highlighting the clinical usefulness of treatment algorithms and the divergent biological, psychological, and clinical efforts to predict the effectiveness of antidepressant treatments, we conclude that the spectrum of different antidepressant treatments has broadened over the last few decades. The efficacy and clinical effectiveness of antidepressants is statistically significant, clinically relevant, and proven repeatedly. Further optimization of treatment can be helped by clearly structured treatment algorithms and the implementation of psychotherapeutic interventions. Modern individualized antidepressant treatment is in most cases a well-tolerated and efficacious approach to minimize the negative impact of otherwise potentially devastating and life-threatening outcomes in depressive disorders.

Clinical differences between early and late remission in depressive patients

OBJECTIVE

Predicting treatment outcome at an early stage is clinically relevant. The main objectives are: to compare rates of remission after acute and continuation phase treatment and to determine the most common residual symptoms among remitted patients; to compare the residual symptoms in early and late remitted and to identify factors that predict early or faster remission.

METHOD

It is a prospective, naturalistic, multicenter, and nationwide epidemiological study of 1595 depressive outpatients. Severity of depressive symptoms was assessed with the Hamilton Depression Rating Scale (HDRS) and the Self Rated Inventory of Depressive Symptomatology (IDS-SR(30)). Assessments were carried out after 6-8 weeks of antidepressant treatment and after 14-20 weeks of continuation treatment. Early remitters were defined with an IDS-SR(30) score ≤ 14 at first and second assessment. Late remitters were defined as those scoring IDS-SR(30) >14 at first and IDS-SR(30) score ≤ 14 at second assessment.

RESULTS

140 subjects (8.8%) were in remission after 6-8 weeks of antidepressant treatment and 862 remitted (59%) after 16-20 weeks of treatment. The mean number of residual symptoms is significantly higher among patients who remit later. Greater differences between early and late remitters were found in the following symptoms: feeling sad, reactivity of mood, interpersonal sensitivity and pleasure/enjoyment. Multivariate analysis showed that only comorbid anxiety disorder is significantly associated with late remission.

CONCLUSIONS

Early remitted patients have a better "quality" of remission. Late remission is associated with residual symptoms more related to core depressive symptoms. Residual symptoms in early remitted patients may constitute a new target for the treatment of depression.

Clinical value of early partial symptomatic improvement in the prediction of response and remission during short-term treatment trials in 3369 subjects with bipolar I or II depression

OBJECTIVE

To evaluate the clinical value of early partial symptomatic improvement in predicting the probability of response during the short-term treatment of bipolar depression.

METHODS

Blinded data from 10 multicenter, randomized, double-blind, placebo-controlled trials in bipolar I or II depression were used to determine if early improvement (≥20% reduction in depression symptom severity after 14 days of treatment) predicted later short-term response or remission. Sensitivity, specificity, efficiency, and positive and negative predictive values (PPV, NPV) were calculated using an intent to treat analysis of individual and pooled study data.

RESULTS

1913 patients were randomized to active compounds (aripiprazole, lamotrigine, olanzapine/olanzapine-fluoxetine, and quetiapine), and 1456 to placebo. In the pooled positive studies, early improvement predicted response and remission with high sensitivity (86% and 88%, respectively), but rates of false positives were high (53% and 59%, respectively). Pooled negative predictive values for response/remission (i.e. confidence in knowing the drug will not result in response or remission) were 74% and 82%, respectively, with low rates of false negatives (14% and 12%, respectively).

CONCLUSION

Early improvement in an individual patient does not appear to be a reliable predictor of eventual response or remission due to an unacceptably high false positive rate. However, the absence of early improvement appears to be a highly reliable predictor of eventual non-response, suggesting that clinicians can have confidence in knowing when a drug is not going to work during short-term treatment. Patients who fail to demonstrate early improvement within the first two weeks of treatment may benefit from a change in therapy.

Targeting remission by 8 weeks: when should supplementation be considered in patients with major depression treated with a specific serotonin reuptake inhibitor?

BACKGROUND

Timely administration/supplementation of a specific serotonin reuptake inhibitor with a second therapeutic agent could improve treatment outcome in patients with major depressive disorder (MDD). The purpose of this study was to identify the optimal time at which to implement supplementation so as to maximize the likelihood of remission by 8 weeks and minimize overtreatment.

METHOD

Data from patients with MDD treated with sertraline (n = 108) or citalopram (n = 107) in a randomized controlled trial were analyzed by multivariate logistic regression. The 21-item Hamilton Depression Scale scores at weeks 1, 2, 3, 4, and 6; sex; age; and baseline Hamilton Anxiety Scale score were used as predictors of remission by 8 weeks sustained for a further 4 weeks.

RESULTS

Regression models for weeks 2, 3, 4, and 6 were significant (area under the curve values, 0.73-0.91). The models for weeks 3 to 6 yielded κ coefficients greater than 0.40 with the outcome variable. A Hamilton Depression Scale reduction score of 50% at week 4 as a criterion for supplementation would have resulted in overtreatment of 4% and 0% of patients in the sertraline and citalopram groups, respectively, and none if applied at week 6. The rates at which patients who should have received supplementation (destined to be nonremitters at 8 weeks) would have been missed would be 49%/54% for sertraline/citalopram at week 4 and 43%/50% at week 6.

LIMITATIONS

The study limitations are as follows: secondary analysis of data, relatively low sertraline dose, and relatively small sample sizes.

CONCLUSIONS

It may be possible to identify patients treated with specific serotonin reuptake inhibitors who will not achieve sustained remission by 8 weeks. If supplementation were implemented accordingly, the number of overtreated patients would be small. However, a substantial number of patients who should be supplemented would be missed, indicating a need for greater sensitivity of the prediction model. Further studies are needed.

A new strategy for antidepressant prescription

From our research and literature search we propose an understanding of the mechanism of action of antidepressants treatments (ADTs) that should lead to increase efficacy and tolerance. We understand that ADTs promote synaptic plasticity and neurogenesis. This promotion is linked with stimulation of dopaminergic receptors. Previous evidence shows that all ADTs (chemical, electroconvulsive therapy, repetitive transcranial magnetic stimulation, sleep deprivation) increase at least one monoamine neurotransmitter serotonin (5-HT), noradrenaline (NA) or dopamine (DA); this article focuses on DA release or turn-over in the frontal cortex. DA increased dopaminergic activation promotes synaptic plasticity with an inverted U shape dose–response curve. Specific interaction between DA and glutamate is mediated by D1 receptor subtypes and Glutamate (NMDA) receptors with neurotrophic factors likely to play a modulatory role. With the understanding that all ADTs have a common, final, DA-ergic stimulation that promotes synaptic plasticity we can predict that (1) AD efficiency is related to the compound strength for inducing DA-ergic stimulation. (2) ADT efficiency presents a therapeutic window that coincides with the inverted U shape DA response curve. (3) ADT delay of action is related to a “synaptogenesis and neurogenesis delay of action.” (4) The minimum efficient dose can be found by starting at a low dosage and increasing up to the patient response. (5) An increased tolerance requires a concomitant prescription of a few ADTs, with different or opposite adverse effects, at a very low dose. (6) ADTs could improve all diseases with cognitive impairments and synaptic depression by increasing synaptic plasticity and neurogenesis.

The importance of early symptom relief in antidepressant treatment: focus on agomelatine

Antidepressants were traditionally considered to have delayed onset of action, and clinical opinion often stated that patients may not experience noticeable improvement for 4-6 weeks. Recent studies have shown, however, that antidepressants have more rapid onset of effect, within 1-2 weeks, and that this early response may be associated with later sustained response. Moreover, there is emerging evidence that some medications may have faster onset of therapeutic effect than others. The new antidepressant agomelatine, with its novel pharmacological profile as an agonist at melatonergic (MT(1) and MT(2)) receptors and antagonist at 5-HT(2C) receptors, has in several studies produced earlier symptom improvement than comparator selective serotonin reuptake inhibitors and serotonin-noradrenaline reuptake inhibitors. In particular, beneficial effects on sleep and daytime functioning are noticeable as early as the first week of treatment. These therapeutic benefits may, in part, be related to its regulatory effects on circadian and sleep- wake cycles. Agomelatine therefore combines early symptom relief with a favorable side-effect profile and short-term and long-term antidepressant efficacy. These properties suggest that agomelatine can be considered a first-line treatment for patients with major depression.

The Timing of Antidepressant Effects: A Comparison of Diverse Pharmacological and Somatic Treatments

Currently available antidepressants used to treat major depressive disorder (MDD) unfortunately often take weeks to months to achieve their full effects, commonly resulting in considerable morbidity and increased risk for suicidal behavior. Our lack of understanding of the precise cellular underpinnings of this illness and of the mechanism of action of existing effective pharmacological treatments is a large part of the reason that therapies with a more rapid onset of antidepressant action (ROAA) have not been developed. Other issues that need to be addressed include heterogeneous clinical concepts and statistical models to measure rapid antidepressant effects. This review describes the timing of onset of antidepressant effects for various therapies used to treat MDD. While several agents produce earlier improvement of depressive symptoms (defined as occurring within one week), the response rate associated with such agents can be quite variable. These agents include both currently available antidepressants as well as other pharmacological and non-pharmacological interventions. Considerably fewer treatments are associated with ROAA, defined as occurring within several hours or one day. Treatment strategies for MDD whose sustained antidepressant effects manifest within hours or even a few days would have an enormous impact on public health.

Does dual antidepressant therapy as initial treatment hasten and increase remission from depression?

BACKGROUND

Only 30%-40% of depressed patients remit after 8 weeks of treatment with an antidepressant. We hypothesized that beginning treatment with two antidepressants would improve remission rates.

METHOD

Relatively treatment-naive depressed outpatients (with DSM-IV diagnoses of major depressive disorder, dysthymic disorder, or depression not otherwise specified) were initially treated with a combination of escitalopram (ESC) plus bupropion (BUP), using rapid dose escalation to ESC 40 mg/day plus BUP 400 to 450 mg/day by study day 15 in an open-label, 8-week study. Remission was defined as a score < or =7 on the 17-item Hamilton Rating Scale for Depression (HAM-D17) at the end of the study. Recruitment occurred between July, 2003, and June, 2006, and the final patient completed the protocol in July, 2006.

RESULTS

Fifty-five patients signed informed consent, 49 of whom received at least one dose of study medication. Of the 49 patients, 28 (57%) were women and 30 (61%) had a current diagnosis of major depressive disorder; the mean age was 38+/-12 years, and the mean pre-treatment HAM-D17 score was 16+/-4. Sixteen (33%) of the patients remitted by study week 2, and 31 (63%) by week 8. Nine patients (18%) dropped out prior to their week 8 visit, 5 of them because of side effects.

LIMITATIONS

The lack of a comparison group and the use of non-blind raters are drawbacks of this study.

CONCLUSIONS

This open-label study suggests that increased numbers of patients may benefit from dual therapy with ESC plus BUP and that the benefit may perhaps include an increased likelihood of early response. Registry: ClinicalTrials.gov: http://www.clinicaltrials.gov/NCT00296712 (Journal of Psychiatric Practice. 2009;15:337-345).

Efficacy of an algorithm-guided treatment compared with treatment as usual: a randomized, controlled study of inpatients with depression

OBJECTIVE

Medication algorithms have been proposed as effective means to offer optimal treatment and improved outcome for patients with severe mental illness. This single-center prospective study compared the efficacy and effects on treatment prescriptions of an algorithm-guided treatment regimen with treatment as usual (TAU) in depressed inpatients.

METHODS

Depressed inpatient participants were randomized to an algorithm-guided standardized stepwise drug treatment regimen (SSTR, n = 74) or TAU (n = 74). The SSTR regimen included sleep deprivation, antidepressant monotherapy, lithium augmentation, monoamine oxidase inhibitor therapy, or electroconvulsive therapy guided by scores on the clinician-rated Bech-Rafaelsen Melancholia Scale. The primary outcome was time to remission (defined as a Bech-Rafaelsen Melancholia Scale score of < or =7). Secondary outcomes were remission rates, number of changes in treatment strategies (types), and the number of different prescribed medications over the treatment period.

RESULTS

Patients receiving SSTR had a significantly shorter time to remission (7.0 +/- 0.9 weeks vs 12.3 +/- 1.8 weeks for TAU). Compared with that in remitters in SSTR, the number of strategy changes was significantly higher in TAU remitters (3.0 +/- 2.7 and 1.0 +/- 1.5) and had more psychotropic medications (fix agents: 3.0 +/- 1.5 and 1.9 +/- 1.1; optional agents: 1.5 +/- 1.0 and 0.9 +/- 0.7). Although more patients dropped out of the SSTR group (33 of SSTR, 12 of TAU), the probability of remission tended to be higher in SSTR.

CONCLUSIONS

Algorithm-guided treatment produces better outcomes and less frequent medication changes than TAU. A systematic, stepwise, measurement-based approach to the treatment of depressed inpatients is warranted.

Does early improvement triggered by antidepressants predict response/remission? Analysis of data from a naturalistic study on a large sample of inpatients with major depression

BACKGROUND

Delayed onset of efficacy of antidepressants and a high proportion of depressed patients being poor or non-responders to antidepressants are well known clinical challenges. Therefore, it seems to be necessary to identify predictors for response and - even more important - for remission. It has been suggested that reduction of depressive symptoms at an early stage of antidepressant treatment may predict treatment outcome. Our objective was to test, if this hypothesis derived from randomized controlled studies (RCTs) in outpatients, would be confirmed in a large naturalistic study in a cohort of inpatients with major depression. Patients were treated with various antidepressants and co-medication according to the protocol based on evidence-based clinical guidelines.

METHODS

This was a large naturalistic prospective study. All patients (N=795) were hospitalized and met DSM-IV criteria for major depression according to a structured clinical interview (SCID). Assessments were conducted biweekly. Several definitions of early improvement (20%, 25% and 30% reduction in HAMD-21 baseline total scores) at two different visits were tested. Sensitivity, specificity and predictive values were calculated for the different definitions of early improvement. ROC-analyses as well as logistic regression models have been performed. Response was defined as 50% improvement of the total baseline HAMD-21 score and remission as a score of </=7 at discharge. Additionally, time to response was analyzed by computing Kaplan-Meier survival estimates for the "best" early improvement definition in comparison to non early improvement. Subgroup analyses were conducted to test whether the results were consistent across treatment subgroups.

RESULTS

48.8% of patients in our sample were remitters. The overall response rate was 79.6%. A 20% reduction of HAMD-21 total baseline score at Day 14 provided a sensitivity of 75% and a specificity of 59% for response prediction. This definition of early improvement was an even more sensitive predictor for remission (80%) with a limited specificity (43%). The AUC value of about 0.68 for early response (20% improvement) indicates good predictability for both time intervals tested (Day 14 and Day 28) and changed only marginally with increased percentages in score reduction (AUC=0.71 and 0.73, respectively). More than one third (37%) of all patients who had not improved at Day 14 showed not response in the later treatment course (this was the case for nearly half of all patients (43%) at Day 28). Similar results were obtained by Kaplan-Meier survival analyses. Log-rank test showed significantly longer time to response in patients with non-early improvement (p<0.0001).

LIMITATIONS

Results were assessed by a post-hoc analysis based on prospectively collected data. Several caveats of a naturalistic design must be mentioned, especially there was no control group and only a limited number of stratification factors could be considered.

CONCLUSION

The results support earlier findings that early improvement in the first two weeks may predict with high sensitivity later response and remission, even in hospitalized patients suffering from a more severe degree of depression. Since we used a naturalistic study design, the data may be considered as a replication of previous results drawn from RCTs in a naturalistic environment. We found a global antidepressant effect which was consistent across treatment subgroups regarding sensitivity values. However, we are aware of the inability of effectiveness studies to draw causal treatment relationships from the uncontrolled approach. Nevertheless, the replication of previous results might indicate that a drug switch during treatment in case of lack of early improvement could be accelerated.

How long should a trial of escitalopram treatment be in patients with major depressive disorder, generalised anxiety disorder or social anxiety disorder? An exploration of the randomised controlled trial database

OBJECTIVE

To extend the knowledge of course of improvement in patients with major depressive disorder (MDD), social anxiety disorder (SAD) or generalised anxiety disorder (GAD) participating in randomised placebo-controlled trials (RCTs) and to infer the optimal duration of initial escitalopram treatment in clinical practice, after which intervention might be reasonable in case of non-response.

METHODS

Post hoc analysis of pooled clinical trial database for escitalopram in MDD (14 studies), GAD (4 studies) and SAD (2 studies). 'Onset' of action was defined as a 20% or more decrease from baseline score in disorder-specific psychopathological rating scales: 'response' as a 50% or more decrease from baseline score.

RESULTS

In MDD, the probability of responding at week 8 if no onset was apparent at week 2 was 43%; in patients with an onset of effect the probability was nearly 80%. Similar patterns were observed in GAD and SAD. The chance of responding beyond week 4 in MDD, GAD and SAD was 20% or less if no effect had occurred by week 2.

CONCLUSIONS

The pattern of response in these RCTs suggests that in patients with MDD, GAD or SAD in wider clinical practice, a period of at least 4 weeks is worthwhile before considering further intervention.

Time course of response to antidepressants: predictive value of early improvement and effect of additional psychotherapy

BACKGROUND

The full response to antidepressant pharmacotherapy is evident only after several weeks, but considerable improvements may already be visible within the first two weeks. Little is known about the potential influence of additional psychotherapy on the speed of response to antidepressant treatment. We have analysed in more severely depressed inpatients treated with antidepressants i) the predictive value of early improvement for later response and ii) the impact of additional psychotherapy on the time course of response.

METHODS

124 patients with a major depression referred for hospitalized care were randomized to 5 weeks of sertraline (or amitriptyline as a second choice) plus either additional Interpersonal Psychotherapy modified for inpatients (IPT) or Clinical Management (CM). "Improvement" was defined as a decrease of > or = 20% on the 17-item Hamilton Rating Scale for Depression (HAMD). "Onset of response" was defined as sustained improvement (without any subsequent increase in the HAMD) culminating in 50% decrease on the HAMD by week 5.

RESULTS

Early improvement within two weeks was highly predictive of later stable response (> or = 50% decrease on the HAMD at weeks 4 and 5) or stable remission (HAMD score of < or = 7 at weeks 4 and 5), irrespective of the type of medication or additional IPT or CM. Survival analysis of the ITT sample revealed that patients of the IPT group had a shorter time to "onset of response" than patients in the CM group (median: 12 vs. 30 days; p=0.041, Log Rank). However, there was no significant difference in the time to onset of response, when more stringent conditions were used.

LIMITATIONS

Due to ethical restrictions a comparison with an untreated placebo group could not be performed.

CONCLUSIONS

Early improvement is highly predictive for later stable response or remission in more severely depressed inpatients. In combination therapy, the additional benefit of psychotherapy occurs at least as rapid as the response to antidepressants.

A validation analysis of two self-reported HAM-D6 versions

OBJECTIVE

The six items of the clinician-administrated Hamilton Depression Scale (HAM-D(6)) cover the core items of depressive states reflecting the antidepressive effect of medication. In this study, the two self-reported versions of the HAM-D(6) have been psychometrically validated to ensure the unidimensionality of this administration form in patients with mild-to-moderate depression.

METHOD

The item response theory analysis of Mokken was used to test the unidimensionality of both the Interactive Voice Recording System (IVRS) version of the HAM-D(6) and a paper-and-pencil self-reported version (S-HAM-D(6)). Patients with typical major depression and with seasonal affective disorder were included.

RESULTS

The Mokken analysis showed that the two self-reported versions of the HAM-D(6) obtained coefficients of homogeneity above 0.40, similar to the clinician-rated HAM-D(6) and thus implying unidimensionality. By contrast, the full HAM-D(17) versions (self-reported as well as clinician-rated) obtained coefficients of homogeneity below 0.40, implying that the HAM-D(17) is a multidimensional scale.

CONCLUSION

The analysis show that both the IVRS version and the S-HAM-D(6) version are unidimensional self-rating scales for the measurement of depressive states.

Effects of mirtazapine on dehydroepiandrosterone-sulfate and cortisol plasma concentrations in depressed patients

BACKGROUND

Among the neuroactive steroids, dehydroepiandrosterone sulfate (DHEA-S) is at least in part produced in the adrenal gland and is therefore under the control of the hypothalamic-pituitary-adrenocortical (HPA)-system. In the present study, the impact of mirtazapine on DHEA-S and cortisol (COR) levels was investigated in relation to clinical response in depressed patients.

METHODS

A total of 23 inpatients suffering from a major depressive episode (DSM-IV criteria) underwent 5-week treatment with mirtazapine (45 mg/day). Plasma samples were taken weekly at 0800 h and quantified for COR and DHEA-S levels.

RESULTS

Mirtazapine significantly reduced both COR and DHEA-S concentrations, but had no impact on the COR/DHEA-S ratio. The percentage decrease of DHEA-S, but not that of COR was significantly and positively correlated with the percentage reduction in the sum score of the Hamilton Depression Rating Scale at week 5, suggesting a relationship between DHEA-S reduction and clinical efficacy of mirtazapine. There was a significant positive correlation between the decline in COR and DHEA-S levels.

CONCLUSIONS

Apparently, the decrease in COR and DHEA-S concentrations conjointly reflects an attenuating impact of mirtazapine on HPA axis activity, thereby decreasing the adrenal secretion of COR and DHEA-S.

Evidence-based guidelines for treating depressive disorders with antidepressants: a revision of the 2000 British Association for Psychopharmacology guidelines

A revision of the 2000 British Association for Psychopharmacology evidence-based guidelines for treating depressive disorders with antidepressants was undertaken 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 May 2006. Key areas in treating depression were reviewed, and the strength of evidence and clinical implications were considered. The guidelines were drawn up after extensive feedback from participants and interested parties. A literature review is provided, which identifies the quality of evidence to inform the recommendations, the strength of which are based on the level of evidence. 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.

Limitations of current medical treatments for depression: disturbed circadian rhythms as a possible therapeutic target

The proportion of diagnosed depressives prescribed antidepressants has increased markedly over the last 20 years, mainly following the introduction of the selective serotonin reuptake inhibitors. However, currently available antidepressants have notable limitations, relating to their only moderate efficacy relative to placebo, relatively slow onset of action, possible withdrawal symptoms, and problems of compliance. Sleep disturbances are often used to identify newly presenting depressive patients, and may be part of a more general alteration of bodily rhythms. There are links between pharmacological treatments and circadian rhythms in depression, which might represent another, new option for the development of a therapeutic approach to depression treatment. Many antidepressants affect sleep, some are sedative, and others have been used specifically in severely insomniac depressives. Disturbances in circadian rhythms may be an integral part of depressive mechanisms, and normalising them via an innovative mechanism of antidepressant action may be a fruitful avenue in the search for improved antidepressant agents.

Mirtazapine monotherapy versus combination therapy with mirtazapine and aripiprazole in depressed patients without psychotic features: a 4-week open-label parallel-group study

BACKGROUND

There is preliminary evidence that the atypical antipsychotic aripiprazole, which is a partial agonist at D(2) and 5-HT(1A) receptors and a potent antagonist at 5-HT(2A) receptors, may be useful as an augmentation strategy in treatment-resistant depression.

METHOD

In this 4-week open-label non-randomized parallel-group study, the safety and efficacy of aripiprazole as add-on treatment strategy in patients suffering from non-delusional depression was investigated. Forty drug-free depressed inpatients without psychotic symptoms (13 men, 27 women), suffering from a major depressive episode or bipolar disorder, depressive state (DSM-IV criteria), were included in the study. The patients were treated either with mirtazapine monotherapy (45 mg/day) or combination therapy (mirtazapine 45 mg/day plus aripiprazole 15 mg/day) for 4 weeks. Safety and efficacy were assessed weekly using the Hamilton Depression Rating Scale, the Simpson-Angus Scale and the Barnes Akathisia Scale.

RESULTS

Mirtazapine monotherapy and combined treatment with mirtazapine and aripiprazole showed comparable antidepressant effects as assessed at the endpoint of the study period. However, additional administration of aripiprazole accelerated the onset of antidepressant action in patients suffering from treatment-resistant depression. Additive use of aripiprazole reduced the mirtazapine-induced increase in the body mass index. Moreover, mirtazapine had favourable effects on aripiprazole-induced akathisia. No other extrapyramidal side effects were seen in the combination therapy group.

CONCLUSION

Combined therapy with mirtazapine and aripiprazole is a safe and well-tolerated treatment option which may be useful especially in treatment-resistant depression. Double-blind controlled studies are needed to further explore the efficacy and safety of aripiprazole in depressed patients.

Assessing activity onset time and efficacy for clinically effective antidepressant and antimanic drugs in animal models based on dominant-submissive relationships

There is confusion in the literature on the measurement of the drug activity onset time (AOT) for both clinical and non-clinical studies of antidepressant and antimanic drugs. The questions asked are: How often and at which time points should drug effects be measured? At what level of a drug effect should AOT be determined? Is the placebo (control) effect important for consideration of drug AOT? This paper reviews approaches taken to answer these questions and to assess drug therapeutic AOT. The first part of the paper is devoted to a review of methods used in clinical trials with depression as an indication. The second part is focused on approaches taken in animal models of depression and how they could help in assessing drug AOT. Finally, a summary of pharmacological values on which the AOT depends is presented and a new statistical approach to data analysis method proposed. The allied experimental design for pre-clinical and clinical studies may help to characterize and differentiate AOT for available and new generation of antidepressants and antimanic drugs.

Early onset of selective serotonin reuptake inhibitor antidepressant action: systematic review and meta-analysis

CONTEXT

Selective serotonin reuptake inhibitors (SSRIs) are often described as having a delayed onset of effect in the treatment of depression. However, some trials have reported clinical improvement as early as the first week of treatment.

OBJECTIVE

To test the alternative hypotheses of delayed vs early onset of antidepressant action with SSRIs in patients with unipolar depression.

DATA SOURCES

Trials identified by searching CENTRAL, The Cochrane Collaboration database of controlled trials (2005), and the reference lists of identified trials and other systematic reviews.

STUDY SELECTION

Randomized controlled trials of SSRIs vs placebo for the treatment of unipolar depression in adults that reported outcomes for at least 2 time points in the first 4 weeks of treatment (50 trials from >500 citations identified). Trials were excluded if limited to participants older than 65 years or specific comorbidities.

DATA EXTRACTION

Data were extracted on trial design, participant characteristics, and outcomes by a single reviewer.

DATA SYNTHESIS

Pooled estimates of treatment effect on depressive symptom rating scales were calculated for weeks 1 through 6 of treatment. In the primary analysis, the pattern of response seen was tested against alternative models of onset of response. The primary analysis incorporated data from 28 randomized controlled trials (n=5872). A model of early treatment response best fit the experimental data. Treatment with SSRIs rather than placebo was associated with clinical improvement by the end of the first week of use. A secondary analysis indicated an increased chance of achieving a 50% reduction in Hamilton Depression Rating Scale scores by 1 week (relative risk, 1.64; 95% confidence interval, 1.2-2.25) with SSRI treatment compared with placebo.

CONCLUSIONS

Treatment with SSRIs is associated with symptomatic improvement in depression by the end of the first week of use, and the improvement continues at a decreasing rate for at least 6 weeks.

Early response to venlafaxine antidepressant correlates with lower ACTH levels prior to pharmacological treatment

A link between stressful life events and development or exacerbation of depression has been established via a large body of evidence. An alteration in the regulation of the hypothalamic-pituitary-adrenal (HPA) axis in depression has also been associated with an increase in cortisol secretion. As arginine-vasopressin (AVP) plays an important role in the activation of HPA axis during stress, the present study investigated ACTH and cortisol secretory response induced by an AVP-related peptide desmopressin (ddAVP) in patients with major depression. Prior to antidepressant treatment, endocrinological parameters were evaluated and correlated with the clinical response to venlafaxine treatment, which offers a dual antidepressant action. Depressive patients with no other psychiatric pathology were evaluated with 17-item Hamilton Depression Scale (HAM-D) in order to follow-up the response to venlafaxine. After 1 wk of treatment, 60% of patients reduced their initial HAM-D score to at least 25%; this group was classified as early responders. The other group (40%) started to reduce significantly their HAM-D score after 3 wk of treatment and was classified as late responders. After 6 wk of treatment both groups have reduced HAM-D score to at least 25% of the baseline score. Prior to the pharmacological treatment, both early and late responders showed salivary cortisol rhythm and urinary free cortisol (UFC) in 24-h similar to healthy subjects. However, we did observe differences in basal ACTH secretion, showing that the late responder group had higher basal ACTH than both early responders and controls. The ddAVP challenge promoted a robust secretion of ACTH only in late responders, suggesting a different sensitivity of pituitary vasopressin receptor. The differences in clinical response to venlafaxine among depressive patients seem to be related to endocrinological parameters.

Polymorphisms of the glucocorticoid receptor gene and major depression

BACKGROUND

The most consistent biological finding in patients with depression is a hyperactivity of the hypothalamic-pituitary-adrenal (HPA)-axis, which might be caused by impaired glucocorticoid signaling. Glucocorticoids act through the glucocorticoid receptor (GR) for which several polymorphisms have been described. The N363S and BclI polymorphisms have been associated with hypersensitivity to glucocorticoids, whereas the ER22/23EK polymorphism is related to glucocorticoid resistance.

METHODS

We studied whether the susceptibility to develop a depression is related to these polymorphisms by comparing depressive inpatients (n = 490) and healthy control subjects (n = 496). Among depressed patients, we also investigated the relation between GR variants and dysregulation of the HPA-axis, as measured by the combined dexamethasone suppression/corticotropin-releasing hormone (CRH)-stimulation test, clinical response to antidepressive treatment, and cognitive functioning.

RESULTS

Homozygous carriers of the BclI polymorphism and ER22/23EK-carriers had an increased risk of developing a major depressive episode. We found no genetic associations with functional HPA-axis measures in depressed patients. The ER22/23EK-carriers, however, showed a significantly faster clinical response to antidepressant therapy as well as a trend toward better cognitive functioning during depression.

CONCLUSIONS

The BclI and ER22/23EK polymorphisms were associated with susceptibility to develop major depression. In addition, the ER22/23EK polymorphism is associated with a faster clinical response to antidepressant treatment. These findings support the notion that variants of the GR gene might play a role in the pathophysiology of a major depression and can contribute to the variability of antidepressant response.

Two-week delay in onset of action of antidepressants: new evidence

Many sources purport that antidepressants have a delayed onset of action, measured in weeks rather than days. Recent data using weekly or daily mood ratings demonstrate that maximum improvement occurs during the first 2 weeks, with some improvement within the first 3 days. Methodological issues may underlie the delayed-onset hypothesis.

A meta-analysis of early sustained response rates between antidepressants and placebo for the treatment of major depressive disorder

CONTEXT

Pattern analysis suggests that "true" drug response is characterized by clinical improvement that is not subsequently followed by a worsening of symptoms (sustained clinical response). To date, several reports demonstrate that early response rates are equivalent between antidepressant-treated and placebo-treated groups of patients with major depressive disorder, suggesting that patients who demonstrate significant and sustained symptom improvement during the first 2 weeks of treatment are not responding to the antidepressant itself, but to nonspecific, placebo-like factors.

OBJECTIVE

To compare early sustained response rates between antidepressant- and placebo-treated adults with major depressive disorder.

DATA SOURCES

Medline/Pubmed were searched. No year of publication limits were used.

STUDY SELECTION

Randomized, double-blind, placebo-controlled antidepressant trials or pooled reports/meta-analyses of such trials reporting early sustained response rates for major depressive disorder. The decision to include studies in the meta-analysis was performed by 2 reviewers.

DATA EXTRACTION

Data were extracted with the use of a precoded form.

DATA SYNTHESIS

Analyses were performed on the proportion of patients who achieved a sustained response the first 2 weeks of treatment, as well as the first week of treatment. A random-effects model with fixed drug effects was used to combine the studies and make comparisons of sustained early response rates between antidepressant- and placebo-treated groups. Data from 8 reports involving a total of 7121 major depressive disorder patients (4076 randomized to treatment with an antidepressant and 3045 randomized to placebo) were analyzed. Antidepressant-treated patients were more likely to demonstrate sustained clinical response by 2 weeks (odds ratio 2.06, 95% CI: 1.52-2.8) or 1 week of treatment (odds ratio 1.50, 95% CI: 1.08-2.08) than placebo-treated patients.

CONCLUSIONS

The results of the present analysis suggest that "true" drug response can occur the first 2 week as well as the first week of treatment of major depressive disorder with conventional antidepressants.

What should animal models of depression model?

In this article, we discuss what animal models of depression should be attempting to 'model'. One must first determine if the goal is to model the regulatory mechanisms by which antidepressant treatments alleviate the various symptoms of depression, or to model the dysregulatory mechanisms underlying the etiology of those symptoms. When modeling the mechanisms of antidepressant effects, a key feature that is often overlooked is the time course required for behavioral efficacy. Even in the clinical literature, there is considerable confusion and inconsistency in defining and identifying 'time of onset' of clinical effect. Although the 'therapeutic lag' may not be as long as has been commonly believed, it does occur. Observable improvement in either global symptomatology or specific symptoms becomes evident after 7-14 days of treatment, and more complete recovery takes considerably longer. Thus, any model addressing potential mechanisms of antidepressant action should exhibit a similar time-dependency. Second, whether attempting to address mechanisms underlying behavioral effects of antidepressants, or the neurobiological substrates underlying the development and manifestation of depression, it is essential to recognize that the syndrome of depression is a diagnostic construct that includes a variety of disparate symptoms, some of which may be related mechanistically, and others that may not be specific to depression, but may cut across categorical diagnostic schemes. Further, it is critical to recognize the close relationship of depression and anxiety. Psychological studies have suggested that the myriad symptoms of depression and anxiety may be subsumed within a more limited number of distinct behavioral dimensions, such as negative affect (neuroticism), positive affect, or physiologic hyperarousal. These dimensions may be related to the functioning of specific neurobiological systems. Thus, rather than trying to recreate or mimic the entire spectrum of symptoms comprising the syndrome of depression, it may be more informative to develop animal models for these behavioral dimensions. Such models may then provide access not only to the neural regulatory mechanisms underlying effective antidepressant treatment, but may also provide clues to the processes underlying the development and manifestation of depression.

Social functioning: should it become an endpoint in trials of antidepressants?

DSM-IV has recommended use of the Social and Occupational Functioning Scale (SOFAS) as a clinician-rated global assessment scale for measuring social functioning; this scale is analogous to the Clinical Global Impression (CGI) scale traditionally used as a secondary outcome measure in patients with depressive symptoms. However, we believe that health-related quality of life is the most appropriate indicator of social functioning when considering this dimension as an endpoint in clinical trials of antidepressants. As health-related quality of life is a purely subjective measure, patient-rated questionnaires have been found to be most important in this context. In this respect, the Sheehan Disability Scale has been recommended as the most relevant global self-reported assessment of social functioning in trials of antidepressants.A review of questionnaires found that the three most frequently used scales selectively directed at obtaining information about social functioning in trials of antidepressants are the Social Adjustment Scale - Self Report (SAS-SR), the Social Adaptation Self-Evaluation Scale (SASS) and the Short-Form Health Survey (SF-36). However, the number of placebo-controlled trials of antidepressants that have used these scales is still too limited to allow comparisons in terms of responsiveness.Health-related quality of life includes dimensions other than social functioning, e.g. physical health and mental health (including both cognitive and affective problems). The SF-36 includes subscales relating to physical and mental health, which, like the social functioning subscales, are measured in terms of degrees of well being. Another quality-of-life questionnaire, the Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q), covers social, mental and physical problems, in this case measured in terms of degrees of satisfaction. Recently, the Q-LES-Q has been reduced from a comprehensive scale including 60-92 items to a brief version including 15 items. An additional item measures overall life satisfaction. As most of the items in the brief Q-LES-Q include social functioning, the scale can be considered as an alternative to SF-36 or the Sheehan Disability Scale when the focus is on satisfaction with treatment. However, there are insufficient numbers of trials of antidepressants using these questionnaires to allow comparisons. The examples of trials of antidepressants with the SF-36 subscales discussed in this review have mostly involved SSRIs. These trials have demonstrated that although antidepressants improve social functioning compared with placebo over a 6-week treatment period, the endpoint scores are still significantly below the national norms at this point. Only after 12 weeks of therapy are the endpoint scores of the social functioning scales within the limits of the national norms. In relapse prevention trials or in maintenance trials to prevent recurrence of depression, comparisons of social functioning scores with national norms can be important supplementary indicators of the need for treatment. In conclusion, social functioning as part of the health-related concept of the patient-reported quality-of-life measure should constitute an endpoint in trials of antidepressants to help clarify the goals of treatment in patients with major depression. In medium- and long-term trials, SF-36 subscales should be used as a supplement to symptom-orientated scales. In trials of shorter (6-8 weeks) duration, use of other scales such as the SAS-SR, the Q-LES-Q or the Sheehan Disability Scale should be considered. These scales should be considered as supplementary to each other rather than alternatives; it may be necessary to use more than one of these scales in a trial.

Onset of improvement and response to mirtazapine in depression: a multicenter naturalistic study of 4771 patients

The purpose of this open multicenter study of 4771 patients with a DSM-IV diagnosis of Major Depressive Episode was to analyse the response to mirtazapine in general practice and primary care. Patients with a baseline score of at least 20 on the Montgomery-Asberg Depression Rating Scale (MADRS) were treated with mirtazapine for 6 weeks (30 mg/day) and clinically assessed by their psychiatrists at weekly intervals through the MADRS and Clinical Global Improvement (CGI) rating scales. The data analysis was carried out on an "intent-to-treat" basis to collect outcome information on all patients. Our results suggested that the efficacy of the antidepressant effect relates to a nonspecific process. Nearly all patients (95%) showed at least slight improvement at the end of the observation period, while the response to treatment was independent of the clinical forms of depression. In particular, all measures of efficacy displayed the maximum change within the first 2 weeks of treatment, with further improvement occurring at much slower rates. Significant improvement within the first 2 weeks of treatment was highly predictive of the final response, and can serve as a guideline for clinicians when deciding about increased dosage, augmentation, or change of medication in unresponsive patients. Detailed analyses of individual MADRS items showed that mirtazapine's pharmacological profile, unlike selective serotonin reuptake inhibitors, led relatively quickly to a significant reduction of suicidal thoughts, a fact of particular clinical relevance.

Onset of action for duloxetine 60 mg once daily: double-blind, placebo-controlled studies

BACKGROUND

It is widely believed that most antidepressant medications exhibit a delay of 2-4 weeks before clinically relevant improvement can be observed among patients. During this latency period, patients continue to be symptomatic and functionally impaired. Thus, time to onset of effect is an important attribute of a new pharmacotherapy. We assessed the onset of effect for duloxetine, utilizing analytical methods previously recommended in the literature.

METHOD

Efficacy data were pooled from two identical, but independent, randomized, double-blind, placebo-controlled, 9-week clinical trials of duloxetine (60 mg QD). Efficacy measures included the 17-item Hamilton Rating Scale for Depression (HAMD(17)), HAMD(17) subscales (Maier, core, and anxiety), and the Clinical Global Impression of Severity (CGI-S) and Patient Global Impression of Improvement (PGI-I) scales. In each individual study, duloxetine demonstrated statistically significant advantages over placebo on multiple outcomes. The present analysis utilized pooled data to more accurately and fully characterize the onset of effect for duloxetine.

RESULTS

Median times to sustained improvements of 10% and 20% in the HAMD(17) total score among duloxetine-treated patients were 14 days and 21 days, respectively, compared with 34 days and 49 days, respectively, for placebo-treated patients (p < 0.001 for both results). The median time to sustained 30% improvement in HAMD(17) total score was 35 days for duloxetine-treated patients, while the median time for placebo-treated patients was not estimable since less than half of the patients met this criterion by the end of the trial. For duloxetine-treated patients, median times to sustained 10%, 20%, and 30% improvements on the Maier subscale of the HAMD(17) were the same as those for the HAMD(17) total score: 14, 21, and 35 days, respectively. However, in other analyses, changes in core emotional symptoms as measured by subscales of the HAMD(17) were somewhat faster than changes in overall symptomatology. The probabilities of achieving a sustained 30% improvement (Maier subscale) at Week 1 for duloxetine- and placebo-treated patients were 16.2% vs. 4.8%, respectively (p < 0.001). The corresponding probabilities of sustained improvement at Weeks 2 and 3 for duloxetine were 32.5% and 45.4%, respectively, compared to 12.8% and 21.4% for placebo ((p < 0.001 for both comparisons).

CONCLUSION

The absence of an active comparator limits the conclusions which can be drawn regarding the rapidity of onset of clinically meaningful improvement. However, results from the present investigation may be useful to clinicians in consideration of treatment options for individual patients.

Quality assessment of meta-analyses of RCTs of pharmacotherapy in major depressive disorder

BACKGROUND

Meta-analyses (MAs) of randomized controlled trials (RCTs) have the potential to provide the highest level of evidence, but the quality of published MAs has not been systematically assessed. Therefore, we determined reliability was significant (kappa = 0.89; p < 0.05). the quality of reporting in MAs of RCTs of pharmacotherapy for major depressive disorder (MDD) in adults (18-65 years) without comorbidities and examine trends over time.

METHODS

MEDLINE, EMBASE, Healthstar, Psychlit and Cochrane databases were searched (1980-2002) by 4 independent reviewers for MAs of RCTs. Articles meeting inclusion criteria were blinded. Inter-rater reliability (kappa) was evaluated using a test-retest strategy on 4 articles. Quality was (p = 0.74) did not detect a difference in quality of assessed using the QUOROM checklist. Time trends were evaluated by calculating Spearman's rho.

RESULTS

One hundred articles were identified, 68 were excluded [co-morbidities (9), inappropriate comparator (13), inappropriate outcome (15), article not available (5), inappropriate patient population (15), and inappropriate study design (11)]; 32 were included. Initial kappa was 0.81 (p < 0.05). After resolution of disagreements, the test-retest The mean overall quality score was 50.2% (SD 15.8%, range = 16.7-88.9%). The overall score for Titles was very poor (22%), Abstracts (40%) and Methods (49%) were poor, while overall Results score was minimally acceptable (54%). Good quality scores were found for Introduction (91%) and Discussion (97%). No time trends were identified using Spearman's correlation analysis (rho 0.05; p = 0.79). The Mann-Whitney U test articles published before and after the QUOROM.

CONCLUSION

Despite quality guidelines, the average quality of published MAs of antidepressants is barely acceptable (50.2%). A need exists for adherence to standardized reporting and quality guidelines.

A common role for psychotropic medications: memory impairment

The psychopathologic profile of mental disorders is very diverse and psychotropic medications used to treat them differ in their chemical structure. Nevertheless, these drugs share these four characteristics: delayed onset of clinical response, not one of them can be said to cure, there is a high number of non-responders, and the mechanism responsible for their therapeutic action is not known. It is hypothesized that the action of psychotropic medications is memory impairment, understanding memory as the trace left in the nervous system not only by individual experiences but also by genetic and epigenetic phenomena. It is suggested that it would be beneficial to translate some research strategies from the neurobiology of learning and memory to the study of the effects of psychotropic medications. The hypothesis is briefly assessed according to the following three criteria: (a). the comparison between the molecular effects of psychotropic medications and the so-called molecular biology of learning and memory, (b). the effects of these drugs, preferentially after chronic use, on memory tests, and (c). the effects of drugs that impair memory on tests used for screening psychotropic medications. Finally, some general suggestions for future research are pointed out.

Changes in CREB-phosphorylation during recovery from major depression

For decades psychiatrists have been looking for biological state markers measurable by easy blood test in order to follow up and predict early on treatment response in patients with major depression. In the present study we investigated whether or not measuring CREB (cAMP-response-element-binding-protein) phosphorylation in peripheral blood T lymphocytes is a state marker of treatment response. CREB is an ubiquitous key-element of intracellular signal transduction cascades and its transcriptional activity depends on phosphorylation at Ser-133. Several studies in animals demonstrated that the transcriptional activity of CREB is up-regulated by antidepressant treatment. Therefore, it has been hypothesized that antidepressant treatment exerts its therapeutic effect by this mechanism. In the present study, we investigated CREB-phosphorylation in T-lymphocytes of 20 patients before and in the end of week one and two of either psychopharmacological or psychotherapeutic treatment. After two weeks, 15 patients fulfilled the criteria of treatment response (i.e. 30% reduction in HAMD score compared to baseline), whereas five patients did not. In the end of week two, the responders showed a significant increase in CREB-phosphorylation (P = 0.018) compared to the non-responders. This was true for all patients with either treatment regimen. In conclusion, these results indicate for the first time that the increase in CREB-phosphorylation might be a molecular state marker for the response to antidepressant treatment.