A double-blind, randomized comparison of fluvoxamine with mianserin in depressive illness

Pharmacological targeting of cognitive impairment in depression: recent developments and challenges in human clinical research

Impaired cognition is often overlooked in the clinical management of depression, despite its association with poor psychosocial functioning and reduced clinical engagement. There is an outstanding need for new treatments to address this unmet clinical need, highlighted by our consultations with individuals with lived experience of depression. Here we consider the evidence to support different pharmacological approaches for the treatment of impaired cognition in individuals with depression, including treatments that influence primary neurotransmission directly as well as novel targets such as neurosteroid modulation. We also consider potential methodological challenges in establishing a strong evidence base in this area, including the need to disentangle direct effects of treatment on cognition from more generalised symptomatic improvement and the identification of sensitive, reliable and objective measures of cognition.

Sigma-1 Receptor Agonists and Their Clinical Implications in Neuropsychiatric Disorders

Accumulating evidence suggests that sigma-1 receptors play a role in the pathophysiology of neuropsychiatric diseases, as well as in the mechanisms of some selective serotonin reuptake inhibitors (SSRIs). Among the SSRIs, the order of affinity for sigma-1 receptors is as follows: fluvoxamine > sertraline > fluoxetine > escitalopram > citalopram >> paroxetine. Some SSRIs (e.g., fluvoxamine, fluoxetine and escitalopram) and other drugs (donepezil , ifenprodil , dehydroepiandeterone (DHEA)) potentiate nerve-growth factor (NGF)-induced neurite outgrowth in PC12 cells, and these effects could be antagonized by the selective sigma-1 receptor antagonist NE-100. Furthermore, fluvoxamine, donepezil, and DHEA, but not paroxetine or sertraline, improved phencyclidine-induced cognitive deficits in mice, and these effects could be antagonized by NE-100. Several clinical studies showed that sigma-1 receptor agonists such as fluvoxamine and ifenprodil could have beneficial effects in patients with neuropsychiatric disorders. In this chapter, the authors will discuss the role of sigma-1 receptors in the mechanistic action of some SSRIs, donepezil, neurosteroids, and ifenprodil, and the clinical implications for sigma-1 receptor agonists .

Cognition and depression: the effects of fluvoxamine, a sigma-1 receptor agonist, reconsidered

Cognitive impairment is a primary feature of patients with major depressive disorder (MDD) and is characterised by stress-induced neural atrophy. Via alpha-adrenergic, anti-cholinergic and anti-histaminic activities, several antidepressants can cause significant counter-therapeutic cognitive impairment. Evidence is emerging of the involvement of sigma-1 receptor agonism in the mechanism of action of some antidepressants, notably fluvoxamine. Sigma-1 receptors are abundant in areas affected by depression/stress-induced cerebral atrophy and their ligands have a unique pharmacological profile; they may promote neurogenesis and initiate adaptive neural plasticity as a protection/reaction to stress. Fluvoxamine, as a potent sigma-1 receptor agonist, has shown ameliorating effects in animal models of psychosis, depression, stress, anxiety, obsessive-compulsive disorder (OCD) and aggression and has been shown to improve cognitive impairments. In humans, fluvoxamine may repair central nervous system (CNS) atrophy and restore cognitive function. The current review explores the mechanisms through which sigma-1 receptors can modulate cognitive function and examines how antidepressant therapy with fluvoxamine may help improve cognitive outcomes in patients with depression.

Fluvoxamine versus other anti-depressive agents for depression

BACKGROUND

Fluvoxamine, one of the oldest selective serotonin reuptake inhibitors (SSRIs), is prescribed to patients with major depression in many countries. Several studies have previously reviewed the efficacy and tolerability of fluvoxamine for the treatment of major depression. However, these reviews are now outdated.

OBJECTIVES

Our objective is to evaluate the effectiveness, tolerability and side effect profile of fluvoxamine for major depression in comparison with other anti-depressive agents, including tricyclics (TCAs), heterocyclics, other SSRIs, SNRIs, other newer agents and other conventional psychotropic drugs.

SEARCH STRATEGY

We searched the Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trials Register. Trial databases and ongoing trial registers in North America, Europe, Japan and Australia, were handsearched for randomised controlled trials. We checked reference lists of the articles included in the review, previous systematic reviews and major textbooks of affective disorder for published reports and citations of unpublished research. The date of last search was 31 August 2008.

SELECTION CRITERIA

We included all randomised controlled trials, published in any language, that compared fluvoxamine with any other active antidepressants in the acute phase treatment of major depression.

DATA COLLECTION AND ANALYSIS

Two independent review authors inspected citations and abstracts, obtained papers, extracted data and assessed the risk of bias of included studies. We analysed dichotomous data using odds ratios (ORs) and continuous data using the standardised mean difference (SMD). A random effects model was used to combine studies.

MAIN RESULTS

A total of 54 randomised controlled trials (n = 5122) were included. No strong evidence was found to indicate that fluvoxamine was either superior or inferior to other antidepressants regarding response, remission and tolerability. However, differing side effect profiles were evident, especially with regard to gastrointestinal side effects of fluvoxamine when compared to other antidepressants. For example, fluvoxamine was generally associated with a higher incidence of vomiting/nausea (versus imipramine, OR 2.23, CI 1.59 to 3.14; versus clomipramine, OR 2.13, CI 1.06 to 4.27; versus amitriptyline, OR 2.86, CI 1.31 to 2.63).

AUTHORS' CONCLUSIONS

We found no strong evidence that fluvoxamine was either superior or inferior to any other antidepressants in terms of efficacy and tolerability in the acute phase treatment of depression. However, differing side effect profiles were evident. Based on these findings, we conclude that clinicians should focus on practical or clinically relevant considerations, including these differences in side effect profiles.

Are antidepressant drugs that combine serotonergic and noradrenergic mechanisms of action more effective than the selective serotonin reuptake inhibitors in treating major depressive disorder? A meta-analysis of studies of newer agents

BACKGROUND

Recent studies suggest that the treatment of major depressive disorder (MDD) with newer antidepressant drugs that simultaneously enhance norepinephrine and serotonin neurotransmission might result in higher response and remission rates than the selective serotonin reuptake inhibitors (SSRIs). The goal of our work was to compare response rates among patients with MDD treated with either of these two broad categories of antidepressant drugs.

METHODS

Medline/Pubmed, EMBase, clinical trial registries, program syllabi from major psychiatric meetings held since 1995, and documents from relevant pharmaceutical companies were searched for double-blind, randomized trials comparing a newer serotonergic-noradrenergic antidepressant drug (venlafaxine, duloxetine, milnacipran, mirtazapine, mianserin, or moclobemide) with an SSRI for MDD.

RESULTS

Ninety-three trials (n = 17,036) were combined using a random-effects model. Treatment with serotonergic + noradrenergic antidepressant drugs was more likely to result in clinical response than the SSRIs (risk ratio [RR] = 1.059; response rates 63.6% versus 59.3%; p = .003). There was no evidence for heterogeneity among studies combined (p = 1.0). Excluding each individual agent did not significantly alter the pooled RR. With the exception of duloxetine (.985), RRs for response for each individual serotonergic + noradrenergic antidepressant drug were within the 95% confidence interval of the pooled RR (1.019-1.101).

CONCLUSIONS

Serotonergic-noradrenergic antidepressant drugs seem to have a modest efficacy advantage compared with SSRIs in MDD. With the Number Needed to Treat (NNT) statistic as one indicator of clinical significance, nearly 24 patients would need to be treated with dual-action antidepressant drugs instead of SSRIs in order to obtain one additional responder. This difference falls well below the mark of NNT = 10 suggested by the United Kingdom's National Institute of Clinical Excellence but nonetheless might be of public health relevance given the large number of depressed patients treated with SSRI /serotonin-norepinephrine reuptake inhibitor (SNRI) antidepressant drugs. Further research is needed to examine whether larger differences between classes of antidepressant drugs might exist in specific MDD sub-populations or for specific MDD symptoms.

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.

Clinical effects of pharmacological variations in selective serotonin reuptake inhibitors: an overview

Although the selective serotonin reuptake inhibitor (SSRI) class of antidepressants shares a common primary pharmacology, namely the inhibition of serotonin reuptake, their secondary pharmacology is remarkably heterogeneous. Inhibition of serotonin reuptake and the consequent increase in serotonin availability are responsible for the relief of depressive symptoms and for some of the adverse effects of this class of drugs. Transsynaptic effects such as modulation of signalling cascades, gene expression processes and neuroplasticity are also important in the mechanism of action of antidepressants. However, this review shows that secondary properties of the SSRIs may contribute to the differences in efficacy and tolerability between members of the class. For example, fluvoxamine has affinity for sigma(1)-receptors -- a property likely to be responsible for its particular efficacy in delusional depression. By understanding the properties of SSRIs and employing careful selection of agents for individual patients, physicians are more able to tailor antidepressant treatments to their patients' particular circumstances.

Antidepressants and their effect on sleep

Given the relationship between sleep and depression, there is inevitably going to be an effect of antidepressants on sleep. Current evidence suggests that this effect depends on the class of antidepressant used and the dosage. The extent of variation between the effects of antidepressants and sleep may relate to their mechanism of action. This systematic review examines randomised-controlled trials (RCTs) that have reported the effect that antidepressants appear to have on sleep. RCTs are not restricted to depressed populations, since several studies provide useful information about the effects on sleep in other groups. Nevertheless, the distinction is made between those studies because the participant's health may influence the baseline sleep profiles and the effect of the antidepressant. Insomnia is often seen with monoamine oxidase inhibitors (MAOIs), with all tricyclic antidepressants (TCAs) except amitriptyline, and all selective serotonin reuptake inhibitors (SSRIs) with venlafaxine and moclobemide as well. Sedation has been reported with all TCAs except desipramine, with mirtazapine and nefazodone, the TCA-related maprotiline, trazodone and mianserin, and with all MAOIs. REM sleep suppression has been observed with all TCAs except trimipramine, but especially clomipramine, with all MAOIs and SSRIs and with venlafaxine, trazodone and bupropion. However, the effect on sleep varies between compounds within antidepressant classes, differences relating to the amount of sedative or alerting (insomnia) effects, changes to baseline sleep parameters, differences relating to REM sleep, and the degree of sleep-related side effects.

A systematic review of patient-reported outcome instruments measuring sleep dysfunction in adults

Sleep dysfunction can manifest in several ways, ranging from insomnia to somnolence, and from disrupted sleep to lack of restful sleep. Measuring sleep dysfunction is an area of active research and there exist a number of patient-reported outcome instruments that measure various aspects of sleep dysfunction. However, these instruments have not been evaluated systematically. We used a conceptual model of sleep that included four physical domains of general interest to patients and investigators, and cover the breadth of this disorder: sleep initiation; sleep maintenance; sleep adequacy; and somnolence. We next considered the additional health-related quality-of-life (HR-QOL) domains of psychological and social functioning, progressing along the continuum to include health perceptions and opportunity. We then conducted a literature review to identify instruments and, using criteria developed by the Medical Outcomes Trust Scientific Advisory Committee, evaluated these instruments for their potential use in measuring sleep dysfunction. Twenty-two instruments were identified. Six instruments were found to include the four physical domains defined a priori (Basic Nordic Sleep Questionnaire, Leeds Sleep Evaluation Questionnaire, Medical Outcomes Study - Sleep Problems Measures, Pittsburgh Sleep Diary, Pittsburgh Sleep Quality Index, Self-Rated Sleep Questionnaire and the Sleep Dissatisfaction Questionnaire). Several additional instruments addressed at least some of the domains and thus may be useful for specific purposes. A few instruments addressed overall HR-QOL, but did not include all four domains of interest (Functional Outcomes of Sleep Questionnaire, Quality of Life in Insomniacs and the Sleep-Wake Activity Inventory). Two instruments had undergone extensive psychometric evaluation (Medical Outcomes Study - Sleep Problems Measures and Pittsburgh Sleep Quality Index), with only the latter reporting information about interpretability. Our review indicates that measuring sleep dysfunction in adults is an area of active research and that much work still needs to be completed, specifically the study of interpretability and the application of patient preferences or item response theory. The specific research focus should dictate instrument selection.

Subjective assessment of the effects of CNS-active drugs on sleep by the Leeds sleep evaluation questionnaire: a review

The Leeds sleep evaluation questionnaire (LSEQ) comprises ten self-rating 100 mm line analogue questions concerned with sleep and early morning behaviour. A literature search identified 83 studies in peer-reviewed journals that reported the use of the LSEQ for psychopharmacological investigations of drug effects on self-reported aspects of sleep. High internal consistency and reliability of the questionnaire have been demonstrated. Findings from studies involving a variety of psychoactive agents indicated that the LSEQ was able to quantify subjective impressions of sleep and waking and the effects of drugs in healthy volunteers, depressed and insomnia patients. In accordance with their known activity profile nocturnal administration of sedative hypnotic agents and antihistamines induced dose-related improvements in self-reported ease of getting to sleep, and quality of sleep but a decrease in alertness and behavioural integrity the following morning. Psychostimulants, on the other hand, impaired subjective ratings of sleep and increased early morning alertness. Antidepressants and certain anxiolytic agents improved both self-reported sleep aspects and early morning alertness. Treatment effects measured by the LSEQ corresponded to those measured for the same drugs by other assessment methods. These data indicate that the LSEQ is a robust and reliable instrument for psychopharmacological evaluations. Self-evaluations of sleep, as obtained by the LSEQ, can therefore provide consistent and meaningful measures for estimating the effectiveness of sleep modulators and sedative-hypnotic drugs.

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.

Pharmacotherapy of affectively ill suicidal patients

The development of psychopharmacologic strategies for ameliorating the symptoms associated with major psychiatric disorders is relatively recent in the history of medicine. Regarding depression, the past 30 years have seen the advent of several clinically therapeutic antidepressant medication classes. With the advent of these newer and safer antidepressants, more primary care practitioners are prescribing these drugs, and as a result, more people are being prescribed antidepressant medication than ever before. This article reviews this psychopharmacologic revolution that has emerged as a consequence of a greater understanding of the neurochemical perturbations underlying major affective disorders.

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.

Effects of acute and chronic administration of the antidepressants, imipramine, phenelzine and mianserin, on the social behaviour of mice

Effects of imipramine, phenelzine and mianserin on the behaviour of male CDl mice were examined after a single intraperitoneal injection (imipramine, 15.8 and 63.2 mumol/kg; phenelzine, 1 and 8 mumol/kg); mianserin, 0.12 and 0.48 mumol/kg) and after administration for 12-16 days in the drinking fluid (mean daily intake; imipramine, 15.8 and 63.2 mumol/kg; phenelzine, 1 and 8 mumol/kg; mianserin, 0.12, 0.48 and 1.92 mumol/kg). Behaviour was examined by ethological procedures during 5 min encounters with an untreated partner in a familiar situation, the animal's home cage, and in the more aversive environment of an unfamiliar cage. At 30 min after injection, the higher doses of acutely administered imipramine and mianserin decreased aggressive behaviour in the unfamiliar cage. In the home cage, effects of mianserin were only slight, whereas imipramine reduced social investigation at the larger dose and in both test environments decreased digging. Phenelzine increased social investigation in both environments. After chronic administration, each of the drugs increased social investigation in the neutral cage and home cage at some of the dose levels, indicating potential anxiolytic efficacy. Mianserin showed the additional effect of enhancing digging during tests in the neutral cage, which may correlate with its anxiolytic actions. Phenelzine was the only antidepressant to increase aggression during encounters in the neutral cage after chronic administration. The significance of these findings is discussed.

Emergence of depressive symptoms during treatment for panic disorder with specific 5-hydroxytryptophan reuptake inhibitors

Selective serotonin reuptake inhibitors (SSRI) have been established as effective drugs in the treatment of depressive and anxiety disorders. However, there are also reports that they can induce depressive symptoms and suicidal thoughts in patients. Eighty of 230 patients who met the DSM-III-R criteria for panic disorder received, during the course of treatment, fluvoxamine (a selective serotonin reuptake inhibitor) at a dose level between 50-200 mg/day. The patients were clinically evaluated for a history of affective disorder and for the presence of affective symptoms before the treatment and for emergence of depressive symptoms during the treatment. Seven of the 80 patients (9%) developed symptoms of depression despite a good antianxiety response. Five of the 7 patients received fluvoxamine as second choice after tricyclic antidepressants (TCA). These patients had no history of affective disorder, and no symptoms of depression were present before the treatment with fluvoxamine. The depressive symptoms abated after the fluvoxamine was discontinued and TCA or clonazepam was prescribed. The depressive symptoms reappeared when fluoxetine was administered. None of these 7 patients developed depressive symptoms while treated with TCA or clonazepam. Among the 150 patients treated with TCA and benzodiazepines, not a single case of depression was seen in patients without a previous history of depression. These results suggest a vulnerability among some of panic disorder patients to noradrenergic-serotonergic imbalance caused by SSRI, which has to be taken into clinical consideration.

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)