The antidepressant efficacy of citalopram

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.

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.

Citalopram for major depressive disorder in adults: a systematic review and meta-analysis of published placebo-controlled trials

Objective To assess the effectiveness of citalopram for major depressive disorder (MDD) in adults, in a systematic review of all published, randomised, double-blind studies comparing it with a placebo. Data sources Cochrane Central Register of Controlled Trials, Medline, PsychINFO and Embase. Study selection Randomised, double-blind, placebo-controlled studies of citalopram in adults with MDD were included. Studies with medically ill or treatment resistant subjects were excluded, as were studies of relapse prevention. Remission of MDD was defined as a primary outcome, and response or change from baseline scores were defined as secondary. Data extraction Remission, response and symptom improvement scores on the Hamilton Depression Scale, Montgomery-Asberg Depression Rating Scale and Clinical Global Impressions-Severity scales were extracted. A random-effects meta-analysis was carried out on the response rates and symptom improvement scores. Included studies were examined for the presence of bias and small study effects. Results Eight studies (n=2025) met the inclusion criteria. Two studies provided data on remission, but only one of these showed a significant difference between citalopram and placebo (RR=1.59, 95% CI 1.10 to 2.31). Meta-analysis of response rates in five studies (n=1010) revealed significant superiority of citalopram (RR=1.42, 95% CI 1.17 to 1.73). Meta-analysis of change from baseline scores in five studies (n=1541) gave a standardised mean difference (Hedges' g) of -0.27 (95% CI -0.38 to to -0.16), showing a reduction in MDD symptoms to be significant for citalopram relative to placebo. There was no evidence of any significant small study effects. The overall quality of reporting was poor, with insufficient information on the methodology or outcomes. Seven studies received industry sponsorship. Conclusions Data concerning remission rates for citalopram, relative to placebo, are inconclusive. Response rates and symptom reduction scores in citalopram-treated patients with MDD are significantly better relative to placebo treatment, according to a meta-analysis of published reports. Evaluation of unpublished data is necessary to assess more definitively the effectiveness of citalopram for MDD.

Effects of chronic citalopram treatment on 5-HT1A and 5-HT2A receptors in group- and isolation-housed mice

Selective serotonin reuptake inhibitors (SSRI) are characterized by high clinical effectiveness and good tolerability. A 2-3 week delay in the onset of effects is caused by adaptive mechanisms, probably at the serotonergic (5-HT) receptor level. To analyze this in detail, we measured 5-HT(1A) and 5-HT(2A) receptor bindings in vitro after 3 weeks of citalopram treatment (20 mg/kg i.p. daily) in group-housed as well as isolation-housed mice, reflecting neurobiological aspects seen in psychiatric patients. Isolation housing increased somatodendritic (+52%) and postsynaptic (+30-95%) 5-HT(1A) as well as postsynaptic 5-HT(2A) receptor binding (+25-34%), which confirms previous findings. Chronic citalopram treatment did not induce alterations in raphe 5-HT(1A) autoreceptor binding, independent of housing conditions. Housing-dependent citalopram effects on postsynaptic 5-HT(1A) receptor binding were found with increases in group- (+11-42%) but decreases in isolation-housed (-11 to 35%) mice. Forebrain 5-HT(2A) receptor binding decreased between 11 and 38% after chronic citalopram administration, independent of housing conditions. Citalopram's long-term action comprises alterations at the postsynaptic 5-HT(1A) and 5-HT(2A) receptor binding levels. Housing conditions interact with citalopram effects, especially on 5-HT(1A) receptor binding, and should be more strongly considered in pharmacological studies. In general, SSRI-induced alterations were more pronounced and affected more brain regions in isolates, supporting the concept of a higher responsiveness in "stressed" animals. Isolation-induced receptor binding changes were partly normalized by chronic citalopram treatment, suggesting the isolation housing model for further analyses of SSRI effects, especially at the behavioral level.

Effects of antidepressant treatment following myocardial infarction

BACKGROUND

Depression following myocardial infarction is associated with poor cardiac prognosis. It is unclear whether antidepressant treatment improves long-term depression status and cardiac prognosis.

AIMS

To evaluate the effects of antidepressant treatment compared with usual care in an effectiveness study.

METHOD

In a multicentre randomised controlled trial, 2177 myocardial infarction patients were evaluated for ICD-10 depression and randomised to intervention (n=209) or care as usual (n=122). Both arms were evaluated at 18 months post-myocardial infarction for long-term depression status and new cardiac events.

RESULTS

No differences were observed between intervention and control groups in mean scores on the Beck Depression Inventory (11.0, s.d.=7.5 v.10.2, s.d.=5.1, P=0.45) or presence of ICD-10 depression (30.5 v. 32.1%, P=0.68). The cardiac event rate was 14% among the intervention group and 13% among controls (OR=1.07, 95% CI 0.57-2.00).

CONCLUSIONS

Antidepressant treatment did not alter long-term depression post-myocardial infarction status or improve cardiac prognosis.

Effect of chronic citalopram on serotonin-related and stress-regulated genes in the dorsal raphe nucleus of the rat

Using a model of depression in which chronic social stress induces depressive-like symptoms, we investigated effects of the selective serotonin-reuptake inhibitor (SSRI) citalopram on gene expression in the dorsal raphe nucleus of male rats. Expression of tryptophan hydroxylase (TPH) protein was found to be upregulated by the stress and normalized by citalopram, while mRNAs for genes TPH 1 and 2 were differentially affected. Citalopram had no effect on serotonin transporter mRNA but reduced serotonin-1A autoreceptor mRNA in stressed animals. The SSRI prevented the stress-induced upregulation of mRNA for CREB binding protein, synaptic vesicle glycoprotein 2b and the glial N-myc downstream-regulated gene 2, but increased mRNA for neuron-specific enolase (NSE) in both stressed and unstressed animals having no effect on stress-induced upregulation of NSE protein. These findings demonstrate that in the dorsal raphe nucleus of chronically stressed rats, citalopram normalizes TPH expression and blocks stress effects on distinct genes related to neurotransmitter release and neuroplasticity.

Citalopram counteracts depressive-like symptoms evoked by chronic social stress in rats

Recently, we have described a new model of chronic social stress in rats, based on the resident-intruder paradigm. In this model, rats show behavioural changes that may be considered correlates of depressive symptoms, such as anhedonia and motivational deficits. The present study was designed for pharmacological validation of this model. Animals were socially stressed for 5 weeks and, in parallel, after the first week of stress, they were subjected to chronic (4 weeks) treatment with the antidepressant drug citalopram. The drug was administered via drinking water (30 mg/kg). The optimal dose of citalopram was determined in a pilot study. After 4 weeks of treatment, plasma levels of citalopram and its metabolite were found to be within the human therapeutic range. The effects of social stress and citalopram treatment were assessed by behavioural tests. Chronically stressed rats showed reduced locomotor and exploratory activity, reduced sucrose preference and increased immobility time in the forced swimming test. Chronic oral administration of citalopram abolished those effects and normalized behaviours related to motivation and reward sensitivity. These observations provide evidence for the predictive validity of the chronic social stress paradigm as a model of depressive symptoms in rats.

Design and rationale for a randomized, controlled trial of interpersonal psychotherapy and citalopram for depression in coronary artery disease (CREATE)

OBJECTIVE

Recognition that depression is associated with increased morbidity and mortality in coronary artery disease (CAD) patients has augmented the need for evidence-based treatment guidelines. This article presents the design of a multisite, Canadian trial of the efficacy, safety, and tolerability of interpersonal psychotherapy (IPT), an empirically supported, depression-focused therapy, and the selective serotonin reuptake inhibitor citalopram, alone or in combination, in the treatment of major depression in CAD patients.

METHODS

Two hundred eighty stable CAD patients with a current major depressive episode of at least 4 weeks' duration, based on the Structured Clinical Interview for Depression (SCID), and who have a baseline score >19 on a centralized, telephone-administered, 24-item Hamilton Depression Rating Scale (HAM-D) will be randomly assigned to receive 12 weekly IPT sessions or 12 weekly sessions of standardized clinical management (CM). Patients are also randomly assigned to receive 20 to 40 mg per day of citalopram or pill-placebo. This results in a 2-by-2 factorial design with four groups: IPT plus pill-placebo, IPT plus citalopram, CM plus pill-placebo, and CM plus citalopram. This permits the evaluation of both IPT and citalopram. Blinded, centralized, 24-item, HAM-D telephone ratings constitute the primary outcome variable. The self-report Beck Depression Inventory-II is the secondary outcome. Analyses will involve the intent-to-treat principle with last observation carried forward for incomplete assessments.

RESULTS

Not applicable.

CONCLUSIONS

The results of this trial will contribute to the development of evidence-based clinical guidelines for managing depression in the context of CAD.

Preclinical and clinical pharmacology of DOV 216,303, a "triple" reuptake inhibitor

DOV 216,303 [(+/-)-1-(3,4-dichlorophenyl)-3-azabicyclo-[3.1.0]hexane hydrochloride] is the prototype of a class of compounds referred to as "triple" reuptake inhibitors. Such compounds inhibit the reuptake of norepinephrine (NE), serotonin (5-HT), and dopamine (DA), the three neurotransmitters most closely linked to major depressive disorder. DOV 216,303 inhibits [(3)H]NE, [(3)H]5-HT, and [(3)H]DA uptake to the corresponding human recombinant transporters (expressed in HEK 293 cells) with IC(50) values of approximately 20, 14, and 78 nM, respectively. DOV 216,303 is active in tests predictive of antidepressant activity including the mouse forced swim test and reversal of tetrabenazine-induced ptosis and locomotor depression. The pharmacodynamic, pharmacokinetic, and toxicological profile of DOV 216,303 in animals prompted us to initiate clinical studies. In both single and multiple dose studies using normal volunteers, DOV 216,303 was safe and well-tolerated. Furthermore, both C(max) and AUC values were dose-proportional between 5-150 mg. The plasma concentrations of DOV 216,303 at doses >10 mg were in excess of the IC(50) values for inhibition of biogenic amine reuptake. In a Phase II study designed to explore the safety and tolerability of DOV 216,303 in depressed individuals, patients received either 100 mg DOV 216,303 (50 mg b.i.d.) or 40 mg citalopram (20 mg, b.i.d.) for two weeks. A placebo arm was not employed in this study because several institutional review boards required administration of an active control to severely depressed individuals. Time dependent reductions in HAM-D scores (the primary outcome measure) were observed in both the DOV 216,303 and citalopram groups compared to baseline scores (p < 0.0001). The side effect profile was not remarkably different between treatment arms. These findings provide preliminary evidence of a clinically meaningful antidepressant action with a molecule capable of inhibiting the three transmitters most closely linked to major depressive disorder.

Citalopram treatment of paroxetine-intolerant depressed patients

We assessed the tolerability and antidepressant response to citalopram in a group of patients who could not tolerate a recent trial of paroxetine therapy. Sixty-one outpatients with major depressive disorder and a confirmed history of intolerance to paroxetine (mean final dose: 26.7 mg/day) were switched after at least a 1 week washout to citalopram therapy (20 mg/day). During the 6-week, open label treatment protocol, citalopram could be titrated up to a maximum dose of 40 mg/day. Response was evaluated using the Clinical Global Impressions CGI scale, the 24-item Hamilton Rating Scale for Depression, and several other measures of symptoms and quality of life. Fifty-three patients (87%) completed 6 weeks of citalopram therapy (mean intent-to-treat dose: 23.9 mg/day). The specific side effects that were reported to be intolerable during the earlier paroxetine trial typically recurred only less than 30% of the time during citalopram therapy; only 6 patients (10%) dropped out because of adverse events. The intent-to-treat CGI response rate was 56% at study endpoint; 62% of the completers responded. Significant improvement from pretreatment was observed on various symptom measures after two weeks of citalopram therapy. Citalopram therapy was well tolerated, and more than one half of the patients who began treatment improved significantly. Although further work is necessary to assess the relative merits of this within-class switching strategy (as compared to other options), these data provide further evidence that the various selective serotonin reuptake inhibitors do not have interchangeable tolerability profiles.

The use of citalopram in resistant cataplexy

Background: Cataplexy is a disabling component of the narcolepsy tetrad that is sometimes resistant to standard treatment.Case reports: Three of our patients with narcolepsy, including one who had post-traumatic narcolepsy, suffered from intractable cataplexy with failure of treatment with established drugs due to unacceptable side-effects.Results: We explored the use of citalopram (Celexa), the newest and most specific of the serotonin reuptake inhibitors, and were successful in treating cataplexy without significant side-effects. Stimulant drugs remained necessary for controlling symptoms of excessive drowsiness.Conclusions: Citalopram was effective in relieving the symptoms of resistant cataplexy in out patients.

Economic appraisal of citalopram in the management of single-episode depression

A retrospective intent-to-treat analysis (N = 1,339) was conducted to discern the natural course of antidepressant use and direct health service expenditures for the treatment of single-episode depression (DSM-IV code 296.20) among patients initiating antidepressant pharmacotherapy with either a tricyclic antidepressant (TCA) (amitriptyline, N = 237) or a selective serotonin reuptake inhibitor (SSRI) (citalopram, N = 71; fluoxetine, N = 411; paroxetine, N = 334; or sertraline, N = 286). Data were derived from the computer archive of a network-model health maintenance organization for the period of January 1, 1996, through April 30, 1999. Comparisons at the end of the 6-month post-period (180 days) were undertaken between cohorts initiating antidepressant pharmacotherapy with citalopram and each SSRI or TCA. Consistent with the intent-to-treat design, all accrued health service expenditures were assigned to the pharmacotherapeutic option initially prescribed. Multivariate models were adjusted for patient's age, gender, number of concomitant disease state processes, use of health services in the 6-month time frame (180 days) before initiating antidepressant pharmacotherapy, specialty of physician recording a diagnosis of single-episode depression, and the presence or absence of a previous diagnosis of single-episode depression and receipt of antidepressant pharmacotherapy. Patients initiating antidepressant pharmacotherapy with citalopram were far more likely to (1) have been diagnosed by a psychiatrist (37%; p < or = 0.05); (2) continue with the original pharmacotherapeutic option (79%) compared with patients originally prescribed amitriptyline (51%; chi2 = 17.29, df = 1, p < or = 0.05) or sertraline (65%; chi2 = 36.91, df = 1, p < or = 0.05); no significant difference was found compared with patients initiating antidepressant pharmacotherapy with paroxetine (72%; p = not significant [NS]) or fluoxetine (83%; p = NS); (3) obtain 90 days or more of antidepressant pharmacotherapy (86%) compared with those prescribed amitriptyline (69%; chi2 = 8.09, df = 1, p < or = 0.05); no significant difference was found compared with sertraline (77%), paroxetine (81%), or fluoxetine (84%); and (4) obtain 6 months (180 days) of antidepressant pharmacotherapy (68%) compared with those prescribed amitriptyline (39%; chi2 = 18.26, df = 1, p < or = 0.05) or sertraline (51%; chi2 = 6.02, df = 1, p < or = 0.05); no significant difference was found compared with paroxetine (56%) or fluoxetine (59%). Receipt of amitriptyline or sertraline as initial medication was associated with a per capita increase (p < or = 0.05) in health service utilization (17% and 9%, respectively) relative to citalopram. No significant difference (p > 0.05) in health service utilization was discerned between citalopram and either fluoxetine or paroxetine. Multivariate models adjusted for nonrandom assignment to the initial pharmacotherapeutic option confirmed these findings. Further research over a longer time course is warranted.

Prevalence of severe depression in private practice depressed outpatients

The prevalence of severe depression, defined by a score of 50 or less on the Global Assessment of Functioning (GAF) scale, and comparisons between severe and non-severe depression, were studied in 203 consecutive unipolar and bipolar depressed outpatients presenting for treatment of depression in private practice. The prevalence of severe degression was 42%. Of the variables investigated (unipolar/bipolar diagnosis, age at baseline/onset, gender, atypical features, psychotic features, comorbidity, chronicity, recurrences, duration of illness, baseline severity), a bipolar I diagnosis and psychotic features were significantly more common in severe depression, while comorbidity and recurrences were significantly more common in non-severe depression. Contrary to the hypothesis that an affective disorder is a progressive illness, the pattern of severe depression did not show more recurrences, more chronicity, or a longer duration of illness than non-severe depression. The findings might be related to the sample studied, as private patients are usually less severely ill than patients in public or university hospitals.