A double-blind comparison of fluvoxamine, desipramine and placebo in outpatients with depression

Beneficial and harmful effects of tricyclic antidepressants for adults with major depressive disorder: a systematic review with meta-analysis and trial sequential analysis

QUESTION

Tricyclic antidepressants are used to treat depression worldwide, but the adverse effects have not been systematically assessed. Our objective was to assess the beneficial and harmful effects of all tricyclic antidepressants for adults with major depressive disorder.

STUDY SELECTION AND ANALYSIS

We conducted a systematic review with meta-analysis and trial sequential analysis. We searched CENTRAL, MEDLINE, Embase, LILACS and other sources from inception to January 2023 for randomised clinical trials comparing tricyclic antidepressants versus placebo or 'active placebo' for adults with major depressive disorder. The primary outcomes were depressive symptoms measured on the 17-item Hamilton Depression Rating Scale (HDRS-17), serious adverse events and quality of life. The minimal important difference was defined as three points on the HDRS-17.

FINDINGS

We included 103 trials randomising 10 590 participants. All results were at high risk of bias, and the certainty of the evidence was very low or low. All trials only assessed outcomes at the end of the treatment period at a maximum of 12 weeks after randomisation. Meta-analysis and trial sequential analysis showed evidence of a beneficial effect of tricyclic antidepressants compared with placebo (mean difference -3.77 HDRS-17 points; 95% CI -5.91 to -1.63; 17 trials). Meta-analysis showed evidence of a harmful effect of tricyclic antidepressants compared with placebo on serious adverse events (OR 2.78; 95% CI 2.18 to 3.55; 35 trials), but the required information size was not reached. Only 2 out of 103 trials reported on quality of life and t-tests showed no evidence of a difference.

CONCLUSIONS

The long-term effects of tricyclic antidepressants and the effects on quality of life are unknown. Short-term results suggest that tricyclic antidepressants may reduce depressive symptoms while also increasing the risks of serious adverse events, but these results were based on low and very low certainty evidence.

PROSPERO REGISTRATION NUMBER

CRD42021226161.

Individual Differences in Response to Antidepressants: A Meta-analysis of Placebo-Controlled Randomized Clinical Trials

IMPORTANCE

Antidepressants are commonly used worldwide to treat major depressive disorder. Symptomatic response to antidepressants can vary depending on differences between individuals; however, this variability may reflect nonspecific or random factors.

OBJECTIVES

To investigate the assumption of systematic variability in symptomatic response to antidepressants and to assess whether this variability is associated with severity of major depressive disorder, antidepressant class, or year of study publication.

DATA SOURCES

Data used were from a recent network meta-analysis of acute treatment with licensed antidepressants in adults with major depressive disorder. The following databases were searched from inception to January 8, 2016: the Cochrane Central Register of Controlled Trials, CINAHL, Embase, LILACS database, MEDLINE, MEDLINE In-Process, and PsycINFO. Additional sources were international trial registries, drug approval agency websites, and key scientific journals.

STUDY SELECTION

Analysis was restricted to double-blind, randomized placebo-controlled trials with available data at the study's end point.

DATA EXTRACTION AND SYNTHESIS

Baseline and end point means, SDs, number of participants in each group, antidepressant class, and publication year were extracted. The data were analyzed between August 14 and November 18, 2019.

MAIN OUTCOMES AND MEASURES

With the use of validated methods, coefficients of variation were derived for antidepressants and placebo, and their ratios were calculated to compare outcome variability between antidepressant and placebo. Ratios were entered into a random-effects model, with the expectation that response to antidepressants would be more variable than response to placebo. Analysis was repeated after stratifying by baseline severity of depression, antidepressant class (selective serotonin reuptake inhibitors: citalopram, escitalopram, fluoxetine, fluvoxamine, paroxetine, sertraline, and vilazodone; serotonin and norepinephrine reuptake inhibitors: desvenlafaxine and venlafaxine; norepinephrine-dopamine reuptake inhibitor: bupropion; noradrenergic agents: amitriptyline and reboxetine; and other antidepressants: agomelatine, mirtazapine, and trazodone), and publication year.

RESULTS

In the 87 eligible randomized placebo-controlled trials (17 540 unique participants), there was significantly more variability in response to antidepressants than to placebo (coefficients of variation ratio, 1.14; 95% CI, 1.11-1.17; P < .001). Baseline severity of depression did not moderate variability in response to antidepressants. Variability in response to selective serotonin reuptake inhibitors was lower than variability in response to noradrenergic agents (coefficients of variation ratio, 0.88; 95% CI, 0.80-0.97; P = .01), as was the variability in response to other antidepressants compared with noradrenergic agents (coefficients of variation ratio, 0.87; 95% CI, 0.79-0.97; P = .001). Variability also tended to be lower in studies that were published more recently, with coefficients of variation changing by a value of 0.005 (95% CI, 0.002-0.008; P = .003) for every year a study is more recent.

CONCLUSIONS AND RELEVANCE

Individual differences may be systematically associated with responses to antidepressants in major depressive disorder beyond placebo effects or statistical factors. This study provides empirical support for identifying moderators and personalizing antidepressant treatment.

Selective serotonin reuptake inhibitors versus placebo in patients with major depressive disorder. A systematic review with meta-analysis and Trial Sequential Analysis

BACKGROUND

The evidence on selective serotonin reuptake inhibitors (SSRIs) for major depressive disorder is unclear.

METHODS

Our objective was to conduct a systematic review assessing the effects of SSRIs versus placebo, 'active' placebo, or no intervention in adult participants with major depressive disorder. We searched for eligible randomised clinical trials in The Cochrane Library's CENTRAL, PubMed, EMBASE, PsycLIT, PsycINFO, Science Citation Index Expanded, clinical trial registers of Europe and USA, websites of pharmaceutical companies, the U.S. Food and Drug Administration (FDA), and the European Medicines Agency until January 2016. All data were extracted by at least two independent investigators. We used Cochrane systematic review methodology, Trial Sequential Analysis, and calculation of Bayes factor. An eight-step procedure was followed to assess if thresholds for statistical and clinical significance were crossed. Primary outcomes were reduction of depressive symptoms, remission, and adverse events. Secondary outcomes were suicides, suicide attempts, suicide ideation, and quality of life.

RESULTS

A total of 131 randomised placebo-controlled trials enrolling a total of 27,422 participants were included. None of the trials used 'active' placebo or no intervention as control intervention. All trials had high risk of bias. SSRIs significantly reduced the Hamilton Depression Rating Scale (HDRS) at end of treatment (mean difference -1.94 HDRS points; 95% CI -2.50 to -1.37; P < 0.00001; 49 trials; Trial Sequential Analysis-adjusted CI -2.70 to -1.18); Bayes factor below predefined threshold (2.01*10-23). The effect estimate, however, was below our predefined threshold for clinical significance of 3 HDRS points. SSRIs significantly decreased the risk of no remission (RR 0.88; 95% CI 0.84 to 0.91; P < 0.00001; 34 trials; Trial Sequential Analysis adjusted CI 0.83 to 0.92); Bayes factor (1426.81) did not confirm the effect). SSRIs significantly increased the risks of serious adverse events (OR 1.37; 95% CI 1.08 to 1.75; P = 0.009; 44 trials; Trial Sequential Analysis-adjusted CI 1.03 to 1.89). This corresponds to 31/1000 SSRI participants will experience a serious adverse event compared with 22/1000 control participants. SSRIs also significantly increased the number of non-serious adverse events. There were almost no data on suicidal behaviour, quality of life, and long-term effects.

CONCLUSIONS

SSRIs might have statistically significant effects on depressive symptoms, but all trials were at high risk of bias and the clinical significance seems questionable. SSRIs significantly increase the risk of both serious and non-serious adverse events. The potential small beneficial effects seem to be outweighed by harmful effects.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42013004420.

Systematic Review and Meta-Analysis: Dose-Response Relationship of Selective Serotonin Reuptake Inhibitors in Major Depressive Disorder

OBJECTIVE

Previous studies suggested that the treatment response to selective serotonin reuptake inhibitors (SSRIs) in major depressive disorder follows a flat response curve within the therapeutic dose range. The present study was designed to clarify the relationship between dosage and treatment response in major depressive disorder.

METHOD

The authors searched PubMed for randomized placebo-controlled trials examining the efficacy of SSRIs for treating adults with major depressive disorder. Trials were also required to assess improvement in depression severity at multiple time points. Additional data were collected on treatment response and all-cause and side effect-related discontinuation. All medication doses were transformed into imipramine-equivalent doses. The longitudinal data were analyzed with a mixed-regression model. Endpoint and tolerability analyses were analyzed using meta-regression and stratified subgroup analysis by predefined SSRI dose categories in order to assess the effect of SSRI dosing on the efficacy and tolerability of SSRIs for major depressive disorder.

RESULTS

Forty studies involving 10,039 participants were included. Longitudinal modeling (dose-by-time interaction=0.0007, 95% CI=0.0001-0.0013) and endpoint analysis (meta-regression: β=0.00053, 95% CI=0.00018-0.00088, z=2.98) demonstrated a small but statistically significant positive association between SSRI dose and efficacy. Higher doses of SSRIs were associated with an increased likelihood of dropouts due to side effects (meta-regression: β=0.00207, 95% CI=0.00071-0.00342, z=2.98) and decreased likelihood of all-cause dropout (meta-regression: β=-0.00093, 95% CI=-0.00165 to -0.00021, z=-2.54).

CONCLUSIONS

Higher doses of SSRIs appear slightly more effective in major depressive disorder. This benefit appears to plateau at around 250 mg of imipramine equivalents (50 mg of fluoxetine). The slightly increased benefits of SSRIs at higher doses are somewhat offset by decreased tolerability at high doses.

Less is more in antidepressant clinical trials: a meta-analysis of the effect of visit frequency on treatment response and dropout

OBJECTIVE

We investigated how the number of follow-up visits affects response rates and dropout among patients in antidepressant trials for major depressive disorder (MDD).

DATA SOURCES

MEDLINE, PsycINFO, and PubMed were searched to identify trials contrasting antidepressants to placebo or active comparator in adults with depression. The index terms depression-drug therapy, depressive disorder-drug therapy, and antidepressant agents, in addition to the classes and individual generic names of all antidepressants, were combined using the "or" operator. Results were limited to (1) English-language articles, (2) publication year 1985 or later, (3) age group ≥ 18 years, and (4) publication types including clinical trials, controlled clinical trials, meta-analysis, multicenter study, randomized controlled trial, or review.

STUDY SELECTION

Included articles reported trials of approved antidepressant medications for MDD in outpatients aged 18-65 years, were 6-12 weeks in duration, and had response rates specified using a standardized measure. Trials were excluded for enrolling inpatients, pregnant women, psychotic subjects, or those with treatment-resistant depression. These criteria allowed 9,189 articles identified in the literature review to be narrowed to 111 reports.

DATA EXTRACTION

Demographic characteristics, the number of study visits planned in each treatment cell, duration of active treatment, attrition rates, and response rates to medication and placebo were entered into a database.

RESULTS

In a multilevel meta-analysis, active medication versus placebo (OR = 1.96, P < .001), active comparator versus placebo-controlled study design (OR = 1.82, P < .001), and longer versus shorter duration (OR = 1.87, P < .001) were associated with significantly increased odds of treatment response. After controlling for these variables, the number of study visits did not significantly influence response rates (OR = 0.97, P = .877). The odds of dropout were significantly decreased for active comparator versus placebo-controlled trials (OR = 0.67, P = .002) and longer versus shorter duration trials (OR = 0.54, P = .035), while increasing numbers of study visits significantly increased the odds of participant dropout (OR = 2.77, P < .001).

CONCLUSIONS

Visit schedules that are much more frequent than are commonly practiced in the community treatment of depression may increase the expense of clinical trials and make them less generalizable to standard clinical treatment.

Randomized, placebo-controlled trials of antidepressants for acute major depression: thirty-year meta-analytic review

Antidepressant-placebo response-differences (RDs) in controlled trials have been declining, potentially confounding comparisons among older and newer drugs. For clinically employed antidepressants, we carried out a meta-analytic review of placebo-controlled trials in acute, unipolar, major depressive episodes reported over the past three decades to compare efficacy (drug-placebo RDs) of individual antidepressants and classes, and to consider factors associated with year-of-reporting by bivariate and multivariate regression modeling. Observed drug-placebo differences were moderate and generally similar among specific drugs, but larger among older antidepressants, notably tricyclics, than most newer agents. This outcome parallels selective increases in placebo-associated responses as trial-size has increased in recent years. Study findings generally support moderate efficacy of clinically employed antidepressants for acute major depression, but underscore limitations of meta-analyses of controlled trials for ranking drugs by efficacy. We suggest that efficiency and drug-placebo differences may be improved with fewer sites and subjects, and better quality-control of diagnostic and clinical assessments.

Onset of clinical effects and plasma concentration of fluvoxamine in Japanese patients

It is widely accepted that selective serotonin reuptake inhibitors (SSRIs) require 2 to 4 weeks of administration before improvements in emotional symptoms of depression are seen. We evaluated whether early monitoring of Hamilton Rating Scale for Depression (HAMD) scores in patients treated with the SSRI fluvoxamine could predict antidepressant response, and also assessed the relationship between the onset of clinical response following the start of fluvoxamine administration and its plasma concentration. Twelve depressed patients (baseline HAMD score ≥15) received an initial dose of fluvoxamine (50 mg/d) followed by an optimized maintenance dose according to their clinical symptoms after 7 d. HAMD scores and plasma drug concentrations were determined at 7 and 28 d after the first administration. There were 7 responders and 5 non-responders on day 28, as evaluated by HAMD scores. The HAMD score for the responders was significantly lower than that for the non-responders on day 7 (mean±S.D., 11.6±6.1 vs. 26.6±6.5, p=0.006). Thus, the reduction in HAMD score on day 7 was clearly divided between responders and non-responders. On day 28, the plasma concentration of fluvoxamine in responders was lower than that in non-responders (14.2±10.5 ng/ml vs. 44.2±28.1 ng/ml, p=0.051). Furthermore, receiver operating characteristic curve analysis conducted on day 28 revealed an upper concentration threshold of 28.2 ng/ml (p=0.042), with none in the responder group above that level. Our results suggest that HAMD score after the first week of treatment with fluvoxamine and the upper threshold of plasma drug concentration could predict whether a patient is a non-responder.

alpha(1A)- and alpha(1B)-adrenergic receptors differentially modulate antidepressant-like behavior in the mouse

Tricyclic antidepressant (TCA) drugs are used for the treatment of chronic depression, obsessive-compulsive disorder (OCD), and anxiety-related disorders. Chronic use of TCA drugs increases the expression of alpha(1)-adrenergic receptors (alpha(1)-ARs). Yet, it is unclear whether increased alpha(1)-AR expression contributes to the antidepressant effects of these drugs or if this effect is unrelated to their therapeutic benefit. In this study, mice expressing constitutively active mutant alpha(1A)-ARs (CAM alpha(1A)-AR) or CAM alpha(1B)-ARs were used to examine the effects of alpha(1A)- and alpha(1B)-AR signaling on rodent behavioral models of depression, OCD, and anxiety. CAM alpha(1A)-AR mice, but not CAM alpha(1B)-AR mice, exhibited antidepressant-like behavior in the tail suspension test and forced swim test. This behavior was reversed by prazosin, a selective alpha(1)-AR inverse agonist, and mimicked by chronically treating wild type mice with cirazoline, an alpha(1A)-AR agonist. Marble burying behavior, commonly used to model OCD in rodents, was significantly decreased in CAM alpha(1A)-AR mice but not in CAM alpha(1B)-AR mice. In contrast, no significant differences in anxiety-related behavior were observed between wild type, CAM alpha(1A)-AR, and CAM alpha(1B)-AR animals in the elevated plus maze and light/dark box. This is the first study to demonstrate that alpha(1A)- and alpha(1B)-ARs differentially modulate antidepressant-like behavior in the mouse. These data suggest that alpha(1A)-ARs may be a useful therapeutic target for the treatment of depression.

Does study design influence outcome? The effects of placebo control and treatment duration in antidepressant trials

BACKGROUND

Clinicians and researchers synthesize data from randomized controlled trials (RCTs) of antidepressants to make conclusions about the efficacy of medications for depression. All treatments include nonspecific factors in addition to the specific effects of drugs, and study design may influence patient outcomes via nonspecific factors. This study investigated whether placebo control and treatment duration affect the outcome in antidepressant RCTs.

METHODS

Medline and the Cochrane Database were searched to identify RCTs of antidepressants for major depression approved by the Food and Drug Administration. Included studies enrolled outpatient participants aged 18-65, lasted 6-12 weeks, compared an antidepressant to placebo or another antidepressant and were published in English after 1985. Excluded trials enrolled inpatients, pregnant women and subjects with psychosis or mania. Mixed-effects logistic regression models including study type (placebo-controlled or comparator) and study duration (6, 8 or 12 weeks) as fixed effects determined whether these factors affected response and remission rates.

RESULTS

In the 90 trials analyzed, the odds of depression response (OR = 1.79, 95% CI = 1.45-2.17, p < 0.001) and remission (OR 1.53, 95% CI = 1.11-2.11, p < 0.001) were significantly higher in comparator relative to placebo-controlled trials. Trials lasting 8 (OR = 1.37, CI = 1.14-1.64, p = 0.001) and 12 (OR = 1.52, CI = 1.12-2.07, p = 0.008) weeks had significantly greater response rates than 6-week trials without differing themselves.

CONCLUSIONS

Response and remission rates to antidepressants are significantly affected by study type and duration. Clinicians and researchers must consider the study design when interpreting and designing RCTs of antidepressant medications.

Advances in the treatment of geriatric depression

Late-life depression is a rather difficult and complicated issue. Although there have been significant advances in our knowledge in this area, a large number of questions still remain unanswered. The aim of this review is a critical presentation of the current evidence for treatment of depression in the elderly. We summarize the evidence for the effectiveness and safety of a range of proposed treatments, including pharmacological, psychological and alternative therapies and lifestyle changes. The treatments with best evidence of effectiveness are antidepressant pharmacotherapy, electroconvulsive therapy, cognitive–behavioral therapy, psychodynamic psychotherapy, reminiscence therapy, problem-solving therapy and exercise. Implications for future research are discussed.

WITHDRAWN: Treatment discontinuation with selective serotonin reuptake inhibitors (SSRIs) versus tricyclic antidepressants (TCAs)

BACKGROUND

Selective serotonin reuptake inhibitors are thought to have better discontinuation rates (i.e. less people dropping out) than tricyclic and heterocyclic antidepressant drugs. It is important to quantify the drop-out rates of different antidepressant drugs in order to have a better understanding of the relative tolerability of these drugs.

OBJECTIVES

To assess the comparative tolerability of selective serotonin reuptake inhibitors and tricyclic/heterocyclic antidepressant drugs.

SEARCH STRATEGY

We searched the Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trials Registers (1997 to 1999), MEDLINE (1966 to 1999), EMBASE (1974 to 1999) We also searched specialist journals, the reference lists of relevant papers and previous systematic reviews, conference abstracts and government documents. Representatives of the pharmaceutical industry were contacted.

SELECTION CRITERIA

Parallel group randomised controlled trials comparing selective serotonin reuptake inhibitors with tricyclic or heterocyclic antidepressants in people with depression.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and a third reviewer checked any cases of disagreement.

MAIN RESULTS

We included 136 trials. The selective serotonin reuptake inhibitors showed less participants dropping out compared to the tricyclic/heterocyclic group (odds ratio 1.21, 95% confidence interval 1.12 to 1.30). A statistically significant difference was found in total drop-outs between the selective serotonin reuptake inhibitors and the old tricyclics as well as the newer tricyclics. When the selective serotonin reuptake inhibitors were compared to the heterocyclic antidepressants, there was a non significant difference favouring the selective serotonin reuptake inhibitors. The poor tolerability profile of the old tricyclics was explained by differences in drop-outs for side-effects, but not for inefficacy.

AUTHORS' CONCLUSIONS

Whilst selective serotonin reuptake inhibitors do appear to show an advantage over tricyclic drugs in terms of total drop-outs, this advantage is relatively modest. This has implications for pharmaco-economic models, some of which may have overestimated the difference of drop-out rates between selective serotonin reuptake inhibitors and tricyclic antidepressants. These results are based on short-term randomised controlled trials, and may not generalise into clinical practice.

WITHDRAWN: Selective serotonin reuptake inhibitors (SSRIs) versus other antidepressants for depression

BACKGROUND

The relatively new class of antidepressant, the selective serotonin reputake inhibitors (SSRIs), may be better tolerated than the older tricyclic antidepressants. This review compares the efficacy of SSRIs with other antidepressants.

OBJECTIVES

To examine the relative efficacy of selective serotonin reuptake inhibitors (SSRIs) compared to other antidepressants.

SEARCH STRATEGY

The search strategy included a search of (a) Electronic bibliographic databases (MEDLINE, EMBASE); (b) reference lists of related reviews (c) reference lists of all located studies (d) contact with the manufacturer and (e) the Cochrane Group register of controlled trials

SELECTION CRITERIA

Randomised controlled trials comparing selective serotonin reuptake inhibitors with other kinds of antidepressants in the treatment of patients with depressive disorders. The outcome measures assessed included measures of the severity of depression.

DATA COLLECTION AND ANALYSIS

Data were collected from each study the main outcome measurefrom each study. These included: mean Hamilton depression rating scale, mean Montgomery & Asberg depression rating scale, Clinical Global Impression rating scale. An analysis of standardised mean difference of these scales was performed using Review Manager 3.1 software. The presence of heterogeneity of treatment effect was assessed

MAIN RESULTS

Ninety-eight trials contributed data to the analysis of the relative efficacy of SSRIs and related drugs with comparator antidepressants (Figure 3 & Appendix 3). Analysis of efficacy was based upon 5044 patients treated with an SSRI or related drug, and 4510 treated with an alternative antidepressant. The standardised effect size for SSRIs and related drugs together versus alternative antidepressants using a fixed effects model was 0.035 (95% CI -0.006 to 0.076; Q = 149.25, df = 97, p < 0.001).

AUTHORS' CONCLUSIONS

There are no clinically significant differences in effectiveness between selective serotonin reuptake inhibitors and tricyclic antidepressants. Treatment decisions need to be based on considerations of relative patient acceptability, toxicity and cost.

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.

Are there differences in the symptoms that respond to a selective serotonin or norepinephrine reuptake inhibitor?

BACKGROUND

We examined two previously published studies comparing a norepinephrine (NE) selective agent, reboxetine, and a serotonin (5-HT) selective agent, fluoxetine, to determine if these agents have different effects on individual depressive symptoms.

METHODS

Both studies were 8-week, double-blind, comparison studies of men and women with DSM III-R major depression. Within-group effect sizes for individual symptom change on the Hamilton Depression Rating Scale (HAMD) were determined in the observed case samples and in patients for whom the symptom was relatively severe at baseline. We required that any significant differences in one sample be cross-validated in the second.

RESULTS

Two hundred fifty-three subjects in study I and 168 subjects in study II were randomized to reboxetine or fluoxetine. In both samples, depressed mood, decreased interest, and psychic anxiety had the greatest change. Effect sizes for all HAMD symptoms were similar for the two drugs. No difference between groups in one sample was replicated in the second. Among subjects with severe symptoms, no significant differences were cross-validated.

CONCLUSIONS

Reboxetine and fluoxetine appear to have similar effects on depressive symptoms. These data suggest that NE and 5-HT selective antidepressant drugs act through the same final common pathway and challenge the belief that symptom differences are useful for antidepressant selection.

Does elimination of placebo responders in a placebo run-in increase the treatment effect in randomized clinical trials? A meta-analytic evaluation

The use of a placebo run-in phase, in which placebo responders are withdrawn from a study before random assignment to treatment condition, has been criticized as favoring the active treatment in clinical trials. We compared the effect size of randomized, placebo-controlled clinical trials (in the treatment of depression with selective serotonin reuptake inhibitors [SSRIs]) that include a placebo run-in phase with those that do not, using a meta-analytic approach. This study differed from earlier meta-analytic studies in that it considered only SSRIs and included only studies using continuous measures of depression, allowing for a more refined assessment of effect size. An extensive literature search identified 43 datasets published between 1980 and 2000 comparing placebo with SSRI and using a continuous measure of depression (usually the Hamilton Depression Rating Scale). We included only studies of at least 6 weeks' duration focusing on treatment for primary acute major depression in adults 18-65 years of age. Studies focusing on depression in specific medical illnesses were not included. Analysis of efficacy was based on 3047 subjects treated with an SSRI antidepressant and 3740 subjects treated with a placebo. There was no statistically significant difference in effect size between the clinical trials that had a placebo run-in phase followed by withdrawal of placebo responders and those trials that did not. Despite the lack of a statistically significant difference between studies of withdrawing early placebo responders and those not using this procedure, this approach is likely to continue to be used widely because it produces large absolute effect sizes. It is recommended that future studies clearly describe these procedures and report the number of subjects dropped from the study for early placebo response and other reasons.

Meta-Analysis of Placebo Rates in Major Depressive Disorder Trials

BACKGROUND

Placebo effects in major depressive disorder (MDD) have received much interest in the medical literature. However, few quantitative analyses have been done in homogeneous populations.

OBJECTIVE

To determine efficacy rates for placebo in patients with MDD; to quantify the correlation between efficacy and publication year, as well as between placebo and drug response rates.

DESIGN

Searching MEDLINE (1966-December 2000), EMBASE (1998-February 2001), HealthSTAR (1975-December 2000), and Cochrane (1980-December 2000) databases, randomized, placebo-controlled trials were retrieved including patients with MDD as defined by Diagnostic and Statistical Manual of Mental Disorders, 3rd and 4th editions criteria, Hamilton Rating Scale for Depression score >/=18 or Montgomery-Asberg Depression Rating Scale score >/=16, reporting successes as 50% decreases in scores after 6-8 weeks of treatment. Response rates were summarized using a random effects meta-analysis for per protocol (PP) and intent-to-treat (ITT) results.

RESULTS

We included 24 of 134 potential studies examining 4459 patients, 1786 on placebo and 2673 on an antidepressant. Placebo response rates were 45.5% (PP) and 26.9% (ITT). Correlations were significant between year and rates (PP rho 0.448, p = 0.042; ITT rho 0.557; p = 0.006), but not for active drugs. Placebo and drug rates were correlated (PP r 0.397, p = 0.020; ITT r 0.539; p = 0.002).

CONCLUSIONS

These placebo rates confirm those reported previously, but were from a homogeneous population. Although statistically significant, the correlation between drug and placebo rates was lower than others reported. During the study period, placebo rates increased linearly; active drugs did not. Correlations between placebo and drug response rates reflected moderate to strong effect sizes. We suggest that current methodology has been unsuccessful in achieving unbiased double-blind conditions not influenced by extra-trial factors, including time.

Selective serotonin reuptake inhibitors versus tricyclic antidepressants: a meta-analysis of efficacy and tolerability

BACKGROUND

A meta-analysis of the efficacy and tolerability of selective serotonin reuptake inhibitors (SSRIs) against tricyclic antidepressants (TCAs) in depressed patients was carried out.

METHODS

Efficacy data from 102 randomised controlled trials (10706 patients) were pooled to provide a summary variance-weighted effect size. Tolerability data from 95 studies (10553 patients) were combined to give variance-weighted relative risk of drop out for all reasons and for adverse effects from each study. The effect of age, treatment setting, severity and TCA dose were examined as well as the performance of individual SSRIs and TCAs where there were sufficient studies.

RESULTS

There is no overall difference in efficacy between SSRIs and TCAs (effect size -0.03, 95% confidence interval -0.09 to 0.03). TCAs do appear more effective in in-patients (-0.23, -0.40 to -0.05) and amitriptyline is more effective than SSRI comparators (-0.14, -0.25 to -0.03) but publication bias cannot be excluded. The SSRIs are better tolerated, with significantly lower rates of treatment discontinuations overall (relative risk 0.88, 0.83 to 0.93; number needed to treat 26) and due to side effects (0.73, 0.67 to 0.80; number needed to treat 33). Individual SSRIs show a similar advantage except for fluvoxamine which does not differ from the TCAs. Individual TCAs show a similar disadvantage in tolerability compared to SSRIs except for dothiepin against which SSRI treatment results in more side-effect related drop outs (2.64, 1.50 to 4.63; number needed to harm 12).

LIMITATIONS

The evidence is from short-term studies and subgroup analyses may result in chance results.

CONCLUSIONS

Overall efficacy between the two classes is comparable but SSRIs are not proven to be as effective as TCAs in in-patients and against amitriptyline. SSRIs have a modest advantage in terms of tolerability against most TCAs.

SSRIs versus other antidepressants for depressive disorder

OBJECTIVES

To examine the relative efficacy of selective serotonin reuptake inhibitors (SSRIs) compared to other antidepressants.

SEARCH STRATEGY

The search strategy included a search of (a) Electronic bibliographic databases (MEDLINE, EMBASE); (b) reference lists of related reviews (c) reference lists of all located studies (d) contact with the manufacturer and (e) the Cochrane Group register of controlled trials

SELECTION CRITERIA

Randomised controlled trials comparing selective serotonin reuptake inhibitors with other kinds of antidepressants in the treatment of patients with depressive disorders. The outcome measures assessed included measures of the severity of depression.

DATA COLLECTION AND ANALYSIS

Data were collected from each study the main outcome measurefrom each study. These included: mean Hamilton depression rating scale, mean Montgomery & Asberg depression rating scale, Clinical Global Impression rating scale. An analysis of standardised mean difference of these scales was performed using Review Manager 3. 1 software. The presence of heterogeneity of treatment effect was assessed

MAIN RESULTS

Ninety-eight trials contributed data to the analysis of the relative efficacy of SSRIs and related drugs with comparator antidepressants (Figure 3 & Appendix 3). Analysis of efficacy was based upon 5044 patients treated with an SSRI or related drug, and 4510 treated with an alternative antidepressant. The standardised effect size for SSRIs and related drugs together versus alternative antidepressants using a fixed effects model was 0. 035 (95% CI -0.006 to 0.076; Q = 149.25, df = 97, p < 0.001).

REVIEWER'S CONCLUSIONS

There are no clinically significant differences in effectiveness between selective serotonin reuptake inhibitors and tricyclic antidepressants. Treatment decisions need to be based on considerations of relative patient acceptability, toxicity and cost.

Selective serotonin reuptake inhibitors versus tricyclic and heterocyclic antidepressants: comparison of drug adherence

BACKGROUND

Selective serotonin reuptake inhibitors are thought to have better discontinuation rates (i.e. less people dropping out) than tricyclic and heterocyclic antidepressant drugs. It is important to quantify the drop-out rates of different antidepressant drugs in order to have a better understanding of the relative tolerability of these drugs.

OBJECTIVES

To assess the comparative tolerability of selective serotonin reuptake inhibitors and tricyclic/heterocyclic antidepressant drugs.

SEARCH STRATEGY

We searched the Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trials Registers (1997 to 1999), MEDLINE (1966 to 1999), EMBASE (1974 to 1999) We also searched specialist journals, the reference lists of relevant papers and previous systematic reviews, conference abstracts and government documents. Representatives of the pharmaceutical industry were contacted.

SELECTION CRITERIA

Parallel group randomised controlled trials comparing selective serotonin reuptake inhibitors with tricyclic or heterocyclic antidepressants in people with depression.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and a third reviewer checked any cases of disagreement.

MAIN RESULTS

We included 136 trials. The selective serotonin reuptake inhibitors showed less participants dropping out compared to the tricyclic/heterocyclic group (odds ratio 1.21, 95% confidence interval 1.12 to 1.30). A statistically significant difference was found in total drop-outs between the selective serotonin reuptake inhibitors and the old tricyclics as well as the newer tricyclics. When the selective serotonin reuptake inhibitors were compared to the heterocyclic antidepressants, there was a non significant difference favouring the selective serotonin reuptake inhibitors. The poor tolerability profile of the old tricyclics was explained by differences in drop-outs for side-effects, but not for inefficacy.

REVIEWER'S CONCLUSIONS

Whilst selective serotonin reuptake inhibitors do appear to show an advantage over tricyclic drugs in terms of total drop-outs, this advantage is relatively modest. This has implications for pharmaco-economic models, some of which may have overestimated the difference of drop-out rates between selective serotonin reuptake inhibitors and tricyclic antdepressants. These results are based on short-term randomised controlled trials, and may not generalise into clinical practice.

A review of the efficacy of serotonergic and noradrenergic reuptake inhibitors for treatment of major depression

Both norepinephrine and serotonin mediate the effects of antidepressant drugs and a reasonable question is whether the efficacy of these two mechanisms of action is similar. Previous reviews comparing selective serotonergic drugs with tricyclic antidepressants found no differences, but the tricyclic drugs are heterogeneous with respect to mechanism of action. The current review focuses on studies comparing serotonergic agents with antidepressants that act primarily on norepinephrine. The literature was reviewed to identify double-blind, random assignment studies comparing SSRIs and NRIs, with adequate description of methods and outcome. Fifteen studies were identified, which had enrolled a total of over 1500 patients. The rates of response with SSRIs and NRIs, 61.4% and 59.5%, were neither meaningfully nor significantly different. Few predictors of response were identified in these studies. Noradrenergic and serotonergic antidepressants appear to be equally effective. It remains to be determined if they treat the same or different patients.

Discontinuation rates of SSRIs and tricyclic antidepressants: a meta-analysis and investigation of heterogeneity

BACKGROUND

Previous meta-analyses suggest that individuals treated with serotonin-specific reuptake inhibitors (SSRIs) in randomised controlled trials (RCTs) are less likely to discontinue treatment than those on tricyclic antidepressants. This metaanalysis investigates whether this is due to the frequent use in RCTs of older reference tricyclics (imipramine and amitriptyline), which may have worse side-effects than more recent compounds.

METHODS

A meta-analysis of RCTs comparing tricyclic and heterocyclic antidepressants with SSRIs in the treatment of depression.

RESULTS

The overall odds ratio of discontinuation on tricyclic/heterocyclic antidepressants compared with SSRIs was 0.86 (95% CI 0.78-0.94). The odds ratio for reference tricyclics was 0.82 95% CI 0.72-0.23), newer tricyclics 0.89 (95% CI 0.74-1.06), and heterocyclics 1.02 (95% CI 0.78-1.35). The pooled advantage of SSRIs over tricyclics was maintained whether the population studied consisted of younger adults or only the elderly. No differences in discontinuation rates were detected between the SSRIs.

CONCLUSIONS

The lower rate of discontinuation in patients on SSRIs may be due to the use of old tricyclics (which have worse side-effects) as reference compounds. The SSRIs do not show a statistically significant difference in discontinuation rates when compared with newer tricyclics or heterocyclics.

Treatment discontinuation with selective serotonin reuptake inhibitors compared with tricyclic antidepressants: a meta-analysis

OBJECTIVE

To assess treatment discontinuation rates with selective serotonin reuptake inhibitors compared with tricyclic antidepressants.

DESIGN

Meta-analysis of 62 randomised controlled trials.

SUBJECTS

6029 patients with major unipolar depression.

MAIN OUTCOME MEASURES

Pooled risk ratios for drop out rates with respect to all cases of discontinuation and those due to side effects and treatment failure.

RESULTS

The total discontinuation rate was 10% lower with selective serotonin reuptake inhibitors than with tricyclic antidepressants (risk ratio 0.90; 95% confidence interval 0.84 to 0.97) and the drop out rate due to side effects was 25% lower (risk ratio 0.75; 0.66 to 0.84). There was no significant difference between drug classes in the drop out rates for treatment failure. The risk ratios for drop out did not differ significantly between individual selective serotonin reuptake inhibitors.

CONCLUSIONS

Selective serotonin reuptake inhibitors are better tolerated than tricyclic antidepressants as measured by total numbers of drop outs. The definite advantage to selective serotonin reuptake inhibitors is explained by fewer drop outs due to side effects. The overall difference, however, is comparatively small and may not be clinically relevant. Analyses of cost effectiveness should not overestimate the advantage to selective serotonin reuptake inhibitors.

Reversible and selective inhibitors of monoamine oxidase A in the treatment of depressed elderly patients

The treatment of depression in the elderly population needs a thorough and careful work-up and an aggressive therapeutic approach. Any treatment initiative in this population often becomes difficult because of accompanying physical illness, concomitant medication, possible degenerative changes in central nervous system and age-related altered metabolic status. Despite unevenness in research findings, pharmacological treatment remains the mainstay of management of depression among elderly people. Currently available antidepressants, although effective, are problematic because of the increased vulnerability of the elderly to side effects. Recent research efforts to improve the efficacy and safety of drug treatment of depression resulted in development of reversible and selective monoamine oxidase inhibitors of the isoenzyme A (RIMA), with antidepressant efficacy comparable to tricyclic antidepressants and newer generation antidepressants. RIMAs include moclobemide, brofaromine, toloxatone and cimoxatone. Moclobemide is the most investigated available RIMA for therapeutic use at present. Its absorption and disposition in elderly individuals do not differ significantly from those in young healthy volunteers and depressed patients. The results of present clinical studies show that, in elderly depressed patients, moclobemide is at least as effective as other antidepressants. Its particular advantage is, however, that it is as well tolerated in elderly people as in younger people. There are only few significant adverse events, and they are generally less frequent and less severe than those with TCAs. An additional attribute of moclobemide seems also to be its beneficial effect on cognitive functions.

The efficacy of selective serotonin re-uptake inhibitors in depression: a meta-analysis of studies against tricyclic antidepressants

A meta-analysis of the efficacy of five selective serotonin re-uptake inhibitors (SSRIs) against non-selective and noradrenergic re-uptake inhibitors (mainly tricyclic antidepressants, TCAs) is presented. Fifty five double- blind studies were identified after excluding those multiply reported or with methodological problems likely to bias the outcome in favour of SSRIs. Standardised effect sizes and 95% confidence intervals were calculated based on the difference in the reduction in mean Hamilton depression rating scale (HDRS) scores for the two antidepressants. For studies not reporting standard deviations, the pooled variance from complete studies was used and a variance-weighted mean effect size calculated. There were no differences in efficacy between SSRIs and comparator antidepressants for SSRIs taken together or individually. If studies were classified into high and low depression scores based on a median split of initial HDRS scores, there was a slight advantage to TCAs in the high HDRS group. In addition, SSRIs were slightly less effective than TCAs in in-patients and against combined serotonin and noradrenaline re-uptake inhibitors (clomipramine and amitriptyline). These findings were accounted for by a clinically significant lower efficacy of paroxetine in these subgroups. In contrast, SSRIs as a group were marginally more effective than noradrenergic antidepressants, a finding accounted for by two studies with sertraline. Fluvoxamine was the only SSRI to have been tested adequately in in-patients, where it displayed equal efficacy to TCAs. This meta-analysis confirms that SSRIs and TCAs are in general equally effective, but suggests that paroxetine's efficacy in in-patients and against clomipramine and amitriptyline is not proven.

Selective serotonin reuptake inhibitors: meta-analysis of efficacy and acceptability

OBJECTIVE

To examine the evidence for using selective serotonin reuptake inhibitors instead of tricyclic antidepressants in the first line treatment of depression.

DESIGN

Meta-analysis of 63 randomised controlled trials comparing the efficacy and acceptability of selective serotonin reuptake inhibitors with those of tricyclic and related antidepressants.

MAIN OUTCOME MEASURES

Improvement in mean scores on Hamilton depression rating scale for 53 randomised controlled trials. Pooled drop out rates from the 58 trials which reported drop out by treatment group.

RESULTS

Among the 20 studies reporting standard deviation for the Hamilton score no difference was found in efficacy between serotonin reuptake inhibitors and tricyclic and related antidepressants (standardised mean difference 0.004, 95% confidence interval -0.096 to 0.105). The difference remained insignificant when the remaining 33 studies that used the 17 item and 21 item Hamilton score were included by ascribing weighted standard deviations. The odds ratio for drop out rate in patients receiving serotonin reuptake inhibitors compared with those receiving tricyclic antidepressants was 0.95 (0.86 to 1.07). Similar proportions in both groups cited lack of efficacy as the reason for dropping out but slightly more patients in the tricyclic group cited side effects (18.8% v 15.4% in serotonin reuptake group).

CONCLUSIONS

Routine use of selective serotonin reuptake inhibitors as the first line treatment of depressive illness may greatly increase cost with only questionable benefit.

Comparative efficacy of antidepressants

Selective serotonin reuptake inhibitors (SSRIs) are a recently developed class of drugs with significantly greater antidepressant efficacy than placebo. Generally, in double-blind comparative trials, all SSRIs demonstrated antidepressant efficacy similar to that of the 'standard' tricyclic antidepressants amitriptyline and imipramine; a meta-analysis of controlled trials found the efficacy of the SSRIs to be equivalent to that of the 2 tricyclics. Nevertheless, because of small patient numbers included in most studies that compare SSRIs with other antidepressants, no definitive statements about relative efficacy can be made. In these studies it is simply possible to state that no statistically significant differences were identified between SSRIs and the comparative antidepressants. Importantly, differences in clinical characteristics exist between the SSRIs-differences in elimination half-life (t1/2 beta) between fluoxetine and/or its metabolite (total t1/2 beta = 330 hours) and other SSRIs (t1/2 beta range = 15 to 30 hours), for example. This has implications in terms of potential drug interactions and must be considered when patients have to be switched to treatment with monoamine oxidase inhibitors. Studies with fluvoxamine have been conducted in both in- and outpatients, whereas trials with other SSRIs have been confined largely to outpatient populations. Fluvoxamine has been associated with a high incidence of nausea (37%), although this may have resulted from high initial dosages (rather than upward dose titration protocols) used in early trials. Of further interest, fluoxetine doses of 20mg may be sufficient to produce a satisfactory antidepressant response, and this SSRI may be particularly useful in patients with chronic retarded depression. More clinical data are required before the efficacy of sertraline and citalopram relative to standard antidepressants can be clearly defined. Preliminary data indicate that SSRIs are effective in the treatment of panic disorder, obsessive-compulsive disorder (OCD), eating (e.g. anorexia and bulimia) and personality disorders (e.g. anger, impulsiveness) and substance abuse (e.g. alcoholism); early results with fluvoxamine in the treatment of panic disorder and OCD, and with fluoxetine in the treatment of bulimia, personality disorders and alcohol abuse, have been encouraging. SSRIs have a more favourable tolerability profile than tricyclic antidepressants and, unlike the tricyclics, are not associated with anticholinergic adverse effects, sedation, cardiotoxicity or weight gain. SSRIs are associated with a relatively high incidence of nausea, particularly if high doses are used at the start of treatment. However, the incidence of nausea appears to decrease as treatment is continued.(ABSTRACT TRUNCATED AT 400 WORDS)