Placebo-controlled efficacy of antidepressants in continuation treatment

Do Nonsuicidal Severely Depressed Individuals with Diabetes Profit from Internet-Based Guided Self-Help? Secondary Analyses of a Pragmatic Randomized Trial

INTRODUCTION

Diabetes mellitus type 1 and type 2 are linked to higher prevalence and occurrences of depression. Internet-based depression- and diabetes-specific cognitive behavioral therapies (CBT) can be effective in reducing depressive symptom severity and diabetes-related emotional distress. The aim of the study was to test whether disease-specific severity indicators moderate the treatment outcome in a 6-week minimally guided web-based self-help intervention on depression and diabetes (GET.ON Mood Enhancer Diabetes (GET.ON M.E.D.)) and to determine its effectiveness in a nonsuicidal severely depressed subgroup.

METHODS

Randomized controlled trial- (RCT-) based data (N = 253) comparing GET.ON M.E.D. to an online psychoeducation control group was used to test disease-specific severity indicators as predictors/moderators of a treatment outcome. Changes in depressive symptom severity and treatment response were examined in a nonsuicidal severely depressed subgroup (CES - D > 40; N = 40).

RESULTS

Major depressive disorder diagnosis at the baseline (p _prf6 = 0.01), higher levels of depression (Beck Depression Inventory II; p _prpo = 0.00; p _prf6 = 0.00), and lower HbA_1c (p _prpo = 0.04) predicted changes in depressive symptoms. No severity indicator moderated the treatment outcome. Severely depressed participants in the intervention group showed a significantly greater reduction in depressive symptom severity (d _prpo = 2.17, 95% Confidence Interval (CI): 1.39-2.96) than the control condition (d _prpo = 0.92; 95% CI: 0.001-1.83), with a between-group effect size of d _prpo = 1.05 (95% CI: 0.11-1.98). Treatment response was seen in significantly more participants in the intervention (4/20; 20%) compared to the control group (0/20, 0%; χ ² (2)(N = 40) = 4.44; p < 0.02). At the 6-month follow-up, effects were maintained for depressive symptom reduction (d _pr6f = 0.71; 95% CI: 0.19-1.61) but not treatment response.

CONCLUSION

Disease-specific severity indicators were not related to a differential effectiveness of guided self-help for depression and diabetes. Clinical meaningful effects were observed in nonsuicidal severely depressed individuals, who do not need to be excluded from web-based guided self-help. However, participants should be closely monitored and referred to other treatment modalities in case of nonresponse.

[Consequences of the monoaminergic systems cross-talk in the antidepressant activity]

Selective serotonin reuptake inhibitors (SSRIs) are the most prescribed antidepressant treatment for treat major depressive disorders. Despite their effectiveness, only 30% of SSRI-treated patients reach remission of depressive symptoms. SSRIs by inhibiting the serotonin transporter present some limits with residual symptoms. Increasing not only serotonin but also norepinephrine and dopamine levels in limbic areas seems to improve remission. Anatomical relationships across serotoninergic, dopaminergic and noradrenergic systems suggest tight reciprocal regulations among them. This review attempts to present, from acute to chronic administration the consequences of SSRI administration on monoaminergic neurotransmission. The serotonin neurons located in the raphe nucleus (RN) are connected to the locus coeruleus (locus coeruleus), the key structure of norepinephrine synthesis, through GABAergic-inhibiting interneurons. Activation of the 5-HT_2A receptors expressed on GABAergic interneurons following SERT-inhibition induces an increase in serotonin leading to inhibitory effect on NE release. Similarly, the serotonin neurons exert negative regulation on dopaminergic neurons from the ventral tegmental area (VTA) through a GABAergic interneuron. These interneurons express the 5-HT_2C and 5-HT₃ receptors inducing an inhibitory effect of 5-HT on DA release. Positive reciprocal connections are also observed through direct projections from the locus coeruleus to the RN and from the VTA to the RN through α₁ and D₂ receptors respectively, both stimulating the serotoninergic activity. Acute SSRI treatment induces only a slight increase in 5-HT levels in limbic areas due to the activation of presynaptic 5-HT_1A and 5-HT_1B autoreceptors counteracting the effects of the transporter blockade. No change in NE levels and a small decrease in the dopaminergic neurotransmission is also observed. These weak changes in monoamine in the limbic areas after acute SSRI treatment seems to be one of key point involved in the onset of action. Following desensitization of the 5-HT_1A and 5-HT_1B autoreceptors, chronic SSRI treatment induces a large increase in the 5-HT neurotransmission. Changes in 5-HT levels at the limbic areas results in a decrease in NE transmission and an increase in DA transmission through an increase in the post-synaptic D₂ receptors sensitivity and not from a change in DA levels, which is mainly due to a desensitization of the 5-HT_2A receptor. The observed decrease of NE neurotransmission could explain some limits of the SSRI therapy and the interest to activate NE system for producing more robust effects. On the other hand, the D₂ sensitization, especially in the nucleus accumbens, stimulates the motivation behavior as well as remission of anhedonia considering the major role of DA release in this structure. Finally, we need to take into account the key role of each monoaminergic neurotransmission to reach remission. Targeting only one system will limit the therapeutic effectiveness. Clinical evidences, including the STAR*D studies, confirmed this by an increase of the remission rate following the mobilization of several monoaminergic transmissions. However, these combinations cannot constitute first line of treatment considering the observed increase of side effects. Such an approach should be adapted to each patient in regard to its particular symptoms as well as clinical history. The next generation of antidepressant therapy will need to take into consideration the interconnections and the interrelation between the monoaminergic systems.

Neurobiological bases and clinical aspects of the use of aripiprazole in treatment-resistant major depressive disorder

Addition of atypical antipsychotics to the therapeutic regimen of patients with unipolar major depressive disorder not responding adequately to their treatment has become a common intervention. With all these agents the observation that low doses that are ineffective in schizophrenia, and thus not blocking dopamine D2 receptors effectively, indicate that their beneficial action is attributable to their action at other receptors. Preclinical research has shown that atypical antipsychotics can reverse the suppression of firing of norepinephrine neurons produced by selective serotonin reuptake inhibitors through their antagonism of 5-HT₂(A) receptors. In the case of aripiprazole, three large placebo-controlled studies in more than 1,000 patients individually concluded to significant antidepressant responses and remissions after a six-week treatment. Aripiprazole addition did not produce more discontinuations due to adverse events than placebo. The most frequently encountered adverse events were akathisia and restlessness. Weight gain was minimal but significant in two of the three studies, suggesting that this side effect is not major problem. There was no significant laboratory abnormalities noted with this strategy. It is proposed that because of its long half-life (approximately 3 days), the doses of aripiprazole were escalated too rapidly in these controlled trials. More gradual titration may lead in routine clinical practice to better outcomes, minimizing side effects and improving remission rates.

The self-reported Montgomery-Asberg Depression Rating Scale is a useful evaluative tool in Major Depressive Disorder

BACKGROUND

The use of Patient-reported Outcomes (PROs) as secondary endpoints in the development of new antidepressants has grown in recent years. The objective of this study was to assess the psychometric properties of the 9-item, patient-administered version of the Montgomery-Asberg Depression Rating Scale (MADRS-S).

METHODS

Data from a multicentre, double-blind, 8-week, randomised controlled trial of 278 outpatients diagnosed with Major Depressive Disorder were used to evaluate the validity, reliability and sensitivity to change of the MADRS-S using psychometric methods. A Receiver Operating Characteristic (ROC) curve was plotted to identify the most appropriate threshold to define perceived remission.

RESULTS

No missing values were found at the item level, indicating good acceptability of the scale. The construct validity was satisfactory: all items contributed to a common underlying concept, as expected. The correlation between MADRS-S and physicians' MADRS was moderate (r = 0.54, p < 0.001) indicating that MADRS-S is complementary rather than redundant to the MADRS. Cronbach's alpha was 0.84, and the stability over time of the scale, estimated on a sub-sample of patients whose health status did not change during the first week of the study, was good (intraclass correlation coefficient of 0.78). MADRS-S sensitivity to change was shown. Using a threshold value of 5, the definition of "perceived remission" reached a sensitivity of 82% and a specificity of 75%.

CONCLUSION

Taking account of patient's perceptions of the severity of their own symptoms along with the psychometric properties of the MADRS-S enable its use for evaluative purposes in the development of new antidepressant drugs.

Recurrent affective disorder: Roots in developmental neurobiology and illness progression based on changes in gene expression

Electrophysiological kindling and behavioral sensitization to psychomotor stimulants and stress provide paradigms for understanding how repeated acute events can leave neurobiological residues in gene expression, accounting for the observed long-lasting alterations in behavioral responsivity. Kindling helps conceptualize how repeated electrical stimulation of the brain can progressively evoke increased behavioral and convulsive responsivity, leading to spontaneous seizures in the absence of exogenous stimulation following sufficient stimulations. As kindling unfolds, a complex spatiotemporal cascade of events occurs and includes the induction of immediate early genes (e.g.,c-fos) and late effector genes (including peptides and growth factors) possibly associated with the observed changes in brain microstructure (e.g., synapse formation, axonal and dendritic sprouting, apoptosis). Behavioral sensitization to psychomotor stimulants and stress has also been shown to induce related but different cascades of effects on immediate early and late effector gene expression. These may be associated with the observed long-lasting alterations in behavioral responsivity based on prior experience. If these types of alterations are put into a developmental context, this would provide a paradigm for understanding how early life events could exert profound and behaviorally relevant biochemical and microstructural effects on the central nervous system of the developing organism. The conceptual overview offered by the sensitization and kindling models suggests that environmentally triggered neurobiological processes do not form a single or static residue but, instead, engage processes related to developmental neurobiology and learning and memory and whose substrate is constantly evolving over an organism's lifetime.

A double-blind, randomized, parallel-group, flexible-dose study to evaluate the tolerability, efficacy and effects of treatment discontinuation with escitalopram and paroxetine in patients with major depressive disorder

This multinational, randomized, double-blind, flexible-dose study evaluated the short- and long-term antidepressant tolerability and efficacy of escitalopram and paroxetine. Tolerability was assessed by monitoring adverse events throughout the study, and discontinuation events during brief treatment interruption and tapered withdrawal. Discontinuation-emergent effects were evaluated in two separate double-blind periods. First, to mimic the consequences of non-compliance, patients were randomized to one of two treatment interruption periods (placebo-substitution for 3-5 days). Second, patients were randomized to a 1-2-week tapered withdrawal period randomly scheduled between weeks 28 and 31. The pre-specified primary efficacy endpoint was the mean change from baseline in total Montgomery-Asberg Depression Rating Scale (MADRS) score at week 8, using the principle of last observation carried forward. A total of 323 patients entered 8 weeks of double-blind treatment and received at least one flexible dose of escitalopram (10-20 mg/day) or paroxetine (20-40 mg/day). Patients who demonstrated evidence of a significant clinical improvement (Clinical Global Impression-Improvement of 1 or 2) at week 8 entered a 19-week, double-blind maintenance period during which they were treated with the same dose they received at week 8, followed by a 1-2-week tapered withdrawal period. A total of 89 patients (28%) withdrew during the study; significantly (P<0.01) more patients withdrew from the paroxetine group (34%) than from the escitalopram group (21%), and significantly (P<0.05) more paroxetine patients withdrew due to lack of efficacy. The mean MADRS total score improved for both treatment groups from baseline to week 8, with no statistical difference between groups. In severely depressed patients (baseline MADRS total score >or=30), escitalopram was superior (P<0.05) to paroxetine at week 27 (end of maintenance treatment). There was a high prevalence of sexual dysfunction at baseline: the mean Arizona Sexual Experience Scale (ASEX) score was approximately 20 points in both treatment groups. Mean total ASEX scores increased slightly above baseline values during the acute period and declined slightly below baseline values towards the end of the maintenance period. During taper and cessation of treatment, patients in the paroxetine group demonstrated significantly more discontinuation symptoms relative to escitalopram based on the Discontinuation Emergent Signs and Symptoms scores.

Comparison of escitalopram and citalopram in outpatients with severe major depressive disorder: a prospective, naturalistic, 8-week study

Objective. Escitalopram is a new selective serotonin reuptake inhibitor indicated for the treatment of major depressive disorder (MDD). The objective of this study is to examine its efficacy in the treatment of severe MDD compared with that of citalopram in daily practice. Method. A prospective, naturalistic, 8-week study was conducted involving 127 patients fulfilling DSM-IV criteria for severe MDD and having a baseline Montgomery-Åsberg Depression Rating Scale (MADRS) score of at least 30. A full non-parsimonious logistic model, called the propensity score, was first defined to reduce bias associated with non-randomization. The primary efficacy analysis was the mean change from baseline to week 8 in MADRS score between the escitalopram and citalopram groups, after stratification on the propensity score. Other efficacy measurements consisted of the Clinical Global Impression of Severity and Improvement scales (CGI-S and CGI-I, respectively), response (defined as a reduction of at least 50% on MADRS from baseline to week 8) and remission rates (defined as MADRS ≤ 12 at week 8), after adjustment on propensity score for escitalopram use. Results. A total of 67 escitalopram-treated patients and 60 citalopram-treated patients were enrolled in this study. Escitalopram reduced mean MADRS total score at week 8 compared with citalopram (-23.5 vs. -17.5; P<0.001). The effect of escitalopram was consistently greater than that of citalopram on the CGI scales. Escitalopram-treated patients were also more likely to respond to treatment (79.4 vs. 44.0%; P<0.001), and remission rates were also in favour of escitalopram (56.9 vs. 11.2%, P<0.001). Analysis of safety data showed better tolerability of escitalopram than that of citalopram. Conclusion. Using adequate methodology to reduce biases due to non-randomization, this study indicates better efficacy and tolerability of escitalopram versus citalopram in severe MDD outpatients.

Development of a capillary zone electrophoretic method to determine six antidepressants in their pharmaceutical preparations. Experimental design for evaluating the ruggedness of method

A capillary zone electrophoresis method is proposed for the separation of six of the antidepressants most used for the treatment of mental illness (clomipramine, paroxetine, fluoxetine, citalopram, fluvoxamine, and trazodone). Optimum conditions for their separation were investigated. A background electrolyte solution consisting of 50 mM phosphate buffer adjusted to pH 2.0, hydrodynamic injection, and 25 kV as separation voltage were used. Relative standard deviations (RSD) were <0.38% and <2.93% for migration time and corrected peak area (n = 24), respectively. Detection limits obtained for the six antidepressants ranged from 0.03 to 0.11 mg L(-1). Stability of the solutions, linear concentration range, accuracy, and precision were examined during validation of the method. A ruggedness test of this method was performed using the fractional factorial model of Plackett-Burman, requiring in our case design of a matrix of 15 experiments, in which the influence of seven factors at three different levels was tested on different electrophoretic results: efficiency; resolution; and corrected peak area. Statistical evaluation of electrophoretic results was achieved by Youden and Steiner's method. The described method is rapid, sensitive, and rugged and it was tested for the pharmaceutical formulation analysis, giving recoveries between 95.6 and 99.1% with respect to the nominal content.

Extended-release venlafaxine in relapse prevention for patients with major depressive disorder

Many studies have demonstrated that venlafaxine is an efficacious and safe treatment for major depressive disorder (MDD). This double-blind, placebo-controlled study was performed to evaluate the efficacy of venlafaxine extended-release (XR) (75-225 mg/day) in the prevention of relapse of depression. Patients with MDD who responded to an 8-week course of venlafaxine XR treatment, i.e., had a score < or = 3 on the Clinical Global Impressions scale-Severity of Illness item (CGI-S) and a 21-item Hamilton Rating Scale for Depression (HAM-D(21)) score < or = 10, were randomly assigned to receive continuation treatment (up to 6 months) with venlafaxine XR (n=161) or placebo (n=157). The main efficacy outcome measure was the number of patients who experienced a relapse of depression. Relapse was defined by either a combination of a patient meeting Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for MDD and a CGI-S score > or = 4, two consecutive CGI-S scores > or = 4, or a final CGI-S score > or = 4 for a patient who withdrew from the study. The cumulative probability of relapse was calculated using the Kaplan-Meier method of survival analysis. During the 6-month evaluation period, significantly more patients in the placebo group had a relapse of MDD than did patients who continued treatment with venlafaxine XR. Cumulative relapse rates at 3 and 6 months were 19 and 28%, respectively, for venlafaxine XR, and 44 and 52%, respectively, for placebo. This study demonstrates that venlafaxine XR is an effective and safe continuation therapy.

Death and dependence: current controversies over the selective serotonin reuptake inhibitors

Recent years have seen a considerable media interest in the adverse effects of the selective serotonin reuptake inhibitors (SSRIs). This has led to claims that these antidepressants may lead to suicide and homicide and that they cause dependence or even addiction. Such claims have caused great concerns to many patients and have confused doctors in both primary care and psychiatric practice. In this article I review the basis of these claims and show that many seem to emerge from the misinterpretation of evidence and the use of imprecise definitions. Although the SSRIs are not free of problems they compare very favourably with other antidepressants and other classes of psychotropic drugs. There is no evidence they are addictive in the formal sense of leading to a drug dependence syndrome. Some suggestions on the way these issues can be more precisely defined and studied in future are given.

Escitalopram 10 mg/day is effective and well tolerated in a placebo-controlled study in depression in primary care

Escitalopram, a selective serotonin reuptake inhibitor (SSRI), was compared to placebo in a study of patients with major depressive disorder (DSM-IV) who had baseline Montgomery-Asberg Depression Rating Scale (MADRS) total scores >or=22 and <or=40. After a 1-week, single-blind placebo period, patients were randomized to receive escitalopram 10 mg/day (n=191) or placebo (n=189) in an 8-week, double-blind period. The primary efficacy analysis of adjusted mean change in MADRS total score from baseline showed a statistically significantly larger effect for escitalopram than for placebo with a treatment difference at week 8 (last observation carried forward, LOCF) of 2.7 points (SE 0.85; P=0.002). In further by-week efficacy analyses, the effect of escitalopram was consistently larger than that of placebo (P<0.05) beginning at week 1 (Clinical Global Impression-Improvement score), week 2 (MADRS score) or week 3 (Clinical Global Impression-Severity score). Escitalopram was very well tolerated with a low overall withdrawal rate similar to that for placebo. Nausea was the only adverse event reported significantly more in escitalopram-treated patients than in placebo-treated patients, although it was infrequent and transient. Escitalopram 10 mg/day had a statistically significantly better antidepressant effect than placebo as early as week 1, and was safe and very well tolerated.

Tratamento da depressão

O tratamento antidepressivo deve ser realizado considerando os aspectos biológicos, psicológicos e sociais do paciente. Na média, não há diferenças significativas em termos de eficácia entre os diferentes antidepressivos mas o perfil em termos de efeitos colaterais, preço, risco de suicídio, tolerabilidade varia bastante o que implica em diferenças na efetividade das drogas para cada paciente. A conduta, portanto, deve ser individualizada. A prescrição profilática de antidepressivos irá depender da intensidade e freqüência dos episódios depressivos. O risco de suicídio dever ser sempre avaliado e se necessário o ECT deverá ser indicado. Não há antidepressivo ideal, entretanto, atualmente existe uma disponibilidade grande de drogas atuando através de diferentes mecanismos de ação o que permite que, mesmo em depressões consideradas resistentes, o tratamento possa obter êxito.