Citalopram 20 mg, citalopram 40 mg and placebo in the prevention of relapse of major depression

Melatonin Reverses the Depression-associated Behaviour and Regulates Microglia, Fractalkine Expression and Neurogenesis in Adult Mice Exposed to Chronic Mild Stress

Depression may be precipitated by the negative impact of chronic stress, which is considered to play a key role in this neuropsychiatric disorder. Interestingly, depressed patients show decreased levels of melatonin. This hormone acts pro-neurogenic and exhibits anti-depressant effects in rodent models of predictive antidepressant-like effects. However, the benefits of melatonin in reversing the deleterious effects of chronic mild stress on the alterations in behaviour and in the neurogenic niche of the hippocampus in male BALB/c mice are unknown. In this study, we compared the effects of melatonin (2.5 mg/kg) and citalopram (5 mg/kg), an antidepressant drug belonging to the selective serotonin reuptake inhibitors, in male BALB/c mice exposed to chronic mild stress (CMS). We also investigated the potential effects of melatonin and citalopram on microglial cells, hippocampal neurogenesis and peripheral cytokine profiles. Melatonin and citalopram induced similar antidepressant-like activities that occurred with some of the the following findings: (1) reversal of the morphological alterations in microglia; (2) reversal of the decreased immunoreactivity to CX3CL1 and CX3CR1 in the dentate gyrus; (3) positive regulation of cell proliferation, survival and complexity of the dendritic trees of doublecortin-cells; and (4) modifications of peripheral CX3CL1 expression. This outcome is consistent with the hypothesis about the antidepressant-like effect of melatonin and supports its relevance as a modulator of the niche in the dentate gyrus.

Longer-term open-label study of adjunctive riluzole in treatment-resistant depression

BACKGROUND

While riluzole has been investigated for the treatment of depression, little is known about its longer-term efficacy and optimal treatment duration in treatment-resistant depression (TRD). The objective of this study is to characterize the longer-term outcome of adjunctive riluzole therapy for TRD in an open-label extension of an 8-week acute treatment trial.

METHODS

The data from 66 patients with TRD who received adjunctive riluzole in a 12-week open-label extension phase were analyzed. Response rates (⩾50% reduction in the Mongomery-Asberg Depression Rating Scale [MADRS] score), relapse rates (a MADRS score of ⩾22 in patients who had previously achieved response), and adverse events were examined in patients who had achieved response at the end of the acute phase and those who had not.

RESULTS

Among acute phase responders, the maintained response rate was 66.7% (8/12) and the relapse rate was 8.3% (1/12). In acute phase non-responders, the response rate was 24.1% (13/54). The most commonly reported adverse event was fatigue (9.1%). Three cases were considered serious adverse events; vomiting (n = 1), shortness of breath (n = 1), and aborted suicide attempt (n = 1).

LIMITATIONS

This longer-term study was open-label and uncontrolled. The sample size was relatively small.

CONCLUSIONS

Longer-term adjunctive riluzole appears relatively well tolerated and beneficial for maintaining previous response. Additionally, approximately one fourth of patients who did not respond to 8-week antidepressant treatment might respond if treated with riluzole for 12 weeks. Those findings warrant further investigation because adjunctive riluzole could represent an option for treatment of depression when standard antidepressants have failed.

Does the rapid response of an antidepressant contribute to better cost-effectiveness? Comparison between mirtazapine and SSRIs for first-line treatment of depression in Japan

AIM

Previous studies indicate that mirtazapine is unique in its quick responsiveness compared to other antidepressants. Although some other studies have evaluated its cost-effectiveness, they have not considered its early stage remission rate. The aim of this study was to address this research gap by using precise clinical data to evaluate the cost-effectiveness of mirtazapine in Japan.

METHODS

We developed a Markov model to reflect the week-by-week transition probabilities. The Markov cycle was set as 1 week. While our clinical parameters were obtained largely from existing meta-analyses, cost data were derived from government reports. Cost-effectiveness was evaluated by incremental cost-effectiveness ratios (ICERs) per quality-adjusted life year estimated based on the probability sensitivity analyses. The ICERs were estimated at 2, 8, 26, and 52 weeks.

RESULTS

In severe depression, the ICERs ranged between JPY 872 153 and 1 772 723. The probability of mirtazapine being cost-effective ranged from 0.75 to 0.99 when the ICER threshold was JPY 5 000 000. In moderate depression, the ICERs ranged between JPY 2 356 499 and 4 770 145. The probability of mirtazapine being cost-effective ranged from 0.55 to 0.83 when the ICER threshold was JPY 5 000 000.

CONCLUSION

When considering the early stage efficacy of mirtazapine, it appeared to be cost-effective compared to selective serotonin reuptake inhibitors, especially for severe depression and in the early stage treatment in the Japanese setting. However, our study has some limitations. First, mirtazapine is compared with batched selective serotonin reuptake inhibitors rather than individual ones. Second, we did not consider antidepressant combination therapy as treatment options.

Melatonin synergizes with citalopram to induce antidepressant-like behavior and to promote hippocampal neurogenesis in adult mice

Adult hippocampal neurogenesis is affected in some neuropsychiatric disorders such as depression. Numerous evidence indicates that plasma levels of melatonin are decreased in depressed patients. Also, melatonin exerts positive effects on the hippocampal neurogenic process and on depressive-like behavior. In addition, antidepressants revert alterations of hippocampal neurogenesis present in models of depression following a similar time course to the improvement of behavior. In this study, we analyzed the effects of both, citalopram, a widely used antidepressant, and melatonin in the Porsolt forced swim test. In addition, we investigated the potential antidepressant role of the combination of melatonin and citalopram (MLTCITAL), its type of pharmacological interaction on depressive behavior, and its effect on hippocampal neurogenesis. Here, we found decreased immobility behavior in mice treated with melatonin (<14-33%) and citalopram (<17-30%). Additionally, the MLTCITAL combination also decreased immobility (<22-35%) in comparison with control mice, reflecting an antidepressant-like effect after 14 days of treatment. Moreover, MLTCITAL decreased plasma corticosterone levels (≤13%) and increased cell proliferation (>29%), survival (>39%), and the absolute number of -associated new neurons (>53%) in the dentate gyrus of the hippocampus. These results indicate that the MLTCITAL combination exerts synergism to induce an antidepressant-like action that could be related to the modulation of adult hippocampal neurogenesis. This outcome opens the opportunity of using melatonin to promote behavioral benefits and hippocampal neurogenesis in depression and also supports the use of the MLTCITAL combination as an alternative to treat depression.

Methodological approaches to the long-term study of antidepressants

It has long been known that most patients with bipolar disorder have a course marked by multiple recurrence of major depressive and manic episodes. More recently, many epidemiological studies have shown that at least 50% of unipolar depressive patients have one or more subsequent episodes of depression in their lifetimes. Likewise, relapse following successful short-term treatment of depression is so common that it is now recommended to prolong treatment in the form of maintenance pharmacotherapy. Interest in preventing the recurrence of depression has been stimulated by the results from long-term trials involving antidepressant drugs and lithium. However, these pharmacological studies suffer somewhat from methodological deficits, making difficult any clear and complete interpretation of their results. While some methodological recommendations have now been established to compensate for previous deficits (eg, definition of relapse and recurrence, duration of acute and maintenance treatments, statistical analysis of efficacy), unfortunately, many key points still remain to be resolved (eg, selection of patients, dosage in maintenance and prophylactic phases, maximum length of a course of treatment, etc).

Relapse prevention with antidepressant drug treatment in depressive disorders: a systematic review

BACKGROUND

Antidepressant drugs can promote remission from acute depressive episodes. Our aim was to establish how long such treatments should be continued to prevent relapse.

METHOD

We did a systematic overview of evidence from randomised trials of continuing treatment with antidepressants in patients with depressive disorders who have responded to acute treatment. Medline, Embase, Cinahl, PsycLIT, Psyndex, and Lilacs were searched.

FINDINGS

Data were pooled from 31 randomised trials (4410 participants). Continuing treatment with antidepressants reduced the odds of relapse by 70% (95% CI 62-78; 2p<0.00001) compared with treatment discontinuation. The average rate of relapse on placebo was 41% compared with 18% on active treatment. The treatment effect seemed to persist for up to 36 months, although most trials were of 12 months' duration, and so the evidence on longer-term treatment requires confirmation. Significantly more participants allocated antidepressants withdrew from the trials than did those allocated to placebo (18% vs 15%, respectively; odds ratio 1.30, 95% CI 1.07-1.59): the treatment effect could be even greater in adherent patients. The two-thirds reduction in risk of depressive relapse seemed to be largely independent of the underlying risk of relapse, the duration of treatment before randomisation, or the duration of the randomly allocated therapy.

INTERPRETATION

Antidepressants reduce the risk of relapse in depressive disorder, and continued treatment with antidepressants would benefit many patients with recurrent depressive disorder. The treatment benefit for an individual patient will depend on their absolute risk of relapse with greater absolute benefits in those at higher risk. Further trials are needed to establish the optimum length of therapy and should include patients who were not well represented in these trials, including those at low risk of relapse.

Efficacy of tianeptine vs placebo in the long-term treatment (16.5 months) of unipolar major recurrent depression*

To compare the efficacy and acceptability of tianeptine vs placebo in the long-term treatment of unipolar major recurrent depression, 268 hospitalized and ambulatory patients meeting DSM III-R criteria for major depression with a 21-item Hamilton depression rating scale (HDRS) score >/= 17 and at least one episode in the previous 5 years received tianeptine in a 6-week multicenter open study. At D42, 185 responders (intention-to-treat population) were randomized for ethical reasons into two unbalanced groups to receive tianeptine 37.5 mg/day (n= 111) or placebo (n= 74) for 16.5 months; 173 of the 185 responders were defined as strict responders (per-protocol population) by an HDRS score which was both < 15 and at least halved vs D1, combined with clinical confirmation by the investigator. The groups were similar at baseline except in the severity of the depressive episode (greater in the tianeptine group: 33 vs 18%, p= 0.018). Relapse (before 6 months) and recurrence (after 6 months) were defined by an HDRS score >/= 15 and/or clinical global impression score >/= 4, and clinical confirmation by the investigator. Visits were at D63 and M3, M6, M9, M12, M15, and M18. Efficacy was measured by the number of relapses and recurrences and their time of onset (Kaplan-Meier survival curve analysis). Between D42 and M18 (intention-to-treat population), relapse and recurrence were less frequent on tianeptine vs placebo (16 vs 36%, p= 0.002). Comparison over time also showed a higher proportion of patients without relapse or recurrence on tianeptine (p< 0.001); the intergroup difference increased with follow-up duration. Secondary analysis of relapse in the intention-to-treat group showed a higher proportion on placebo (p= 0.002); secondary analysis of recurrence over time showed that the difference in the percentages of recurrence-free patients was nonsignificant in the intention-to-treat population (p= 0.067) but significant in the per-protocol population (p= 0.036) in favor of tianeptine. Acceptability did not differ between the groups. Treatment-induced adverse events were rare and mild in both groups. These data support the use of tianeptine in the long-term treatment of unipolar major recurrent depression. Relapse and recurrence were decreased two- to threefold on tianeptine vs placebo with no difference in acceptability between the two groups. Copyright 1997 Doin Editeurs

Comparing SSRIs: From chemistry to clinical choice

Selective serotonin reuptake inhibitors (SSRIs) are widely accepted as the best available treatment for most forms of depression. However, to date, there has been little attempt to differentiate between the members of this class of drugs. Since, unlike the tricyclic antidepressants, the SSRIs have very different chemical structures, it is not unexpected that they may have different pharmacological properties. These differences in pharmacology may, in turn, be expressed in varying pharmacokinetic, efficacy, safety and tolerability profiles which mean that the SSRIs may be a less homogeneous class of compounds than is generally assumed. This review analyses the differences between the SSRIs with the intention of helping the practising clinician to select the most appropriate drug for a particular patient.

The SSRIs: advantages, disadvantages and differences

The highly specific mechanism of action of the selective serotonin re-uptake inhibitors (SSRIs) confers advantages on this group, relative to other classes of antidepressant, and thus represents a significant advance in the pharmacotherapy of depression. Whilst their clinical efficacy is equivalent to that of the tricyclic antidepressants (TCAs), the SSRIs have a greatly reduced risk of toxicity in overdose and have been shown to be significantly better tolerated. Specifically, the SSRIs have a low incidence of anticholinergic effects and are essentially devoid of cardiotoxicity. This tolerability advantage may be of significance in improving compliance and hence cost-effectiveness of treatment, particularly in the long term. Despite a lack of sedative effect, there is evidence that SSRIs are more effective than TCAs in the treatment of depression with anxiety. In addition, the SSRIs have been shown to be effective in obsessive-compulsive disorder, panic disorder and social phobia. Although superior efficacy has not been demonstrated for any one of the SSRIs, the structural diversity of this group is reflected in emerging qualitative and quantitative differences in side effects and drug interaction potential. Many of these differential features reflect important variations in pharmacological and pharmacokinetic profiles, including dosage flexibility, washout times, dose-plasma level proportionality and age-related changes in plasma levels. Fluoxetine, for example, has a considerably longer half-life than other SSRIs and side effects and drug interactions may thus occur for an extended period following discontinuation of treatment. Significant differences in the potential for drug interactions in this group are related to their relative potency for inhibition of important liver drug-metabolising enzymes including CYPIID6, CYPIA2 and CYPIIIA4. Large comparative clinical trials of the different SSRIs have yet to be undertaken; however, the differences that have already become apparent provide important information enabling the physician to choose an SSRI appropriate to the individual patient.