Loss of drug effects during continuation therapy

Failure to Respond after Reinstatement of Antidepressant Medication: A Systematic Review

BACKGROUND

Following remission of an anxiety disorder or a depressive disorder, antidepressants are frequently discontinued and in the case of symptom occurrence reinstated. Reinstatement of antidepressants seems less effective in some patients, but an overview is lacking. This systematic review aimed to provide insight into the magnitude and risk factors of response failure after reinstatement of antidepressants in patients with anxiety disorders, depressive disorders, obsessive-compulsive disorder (OCD), or posttraumatic stress disorder (PTSD).

METHOD

PubMed, Embase, and trial registers were systematically searched for studies in which patients: (1) had an anxiety disorder, a depressive disorder, OCD, or PTSD and (2) experienced failure to respond after reinstatement of a previously effective antidepressant.

RESULTS

Ten studies reported failure to respond following antidepressant reinstatement. The phenomenon was observed in 16.5% of patients with a depressive disorder, OCD, and social phobia and occurred in all common classes of antidepressants. The range of response failure was broad, varying between 3.8 and 42.9% across studies. No risk factors for failure to respond were investigated. The overall study quality was limited.

CONCLUSION

Research investigating response failure is scarce and the study quality limited. Response failure occurred in a substantial minority of patients. Contributors to the relevance of this phenomenon are the prevalence of the investigated disorders, the number of patients being treated with antidepressants, and the occurrence of response failure for all common classes of antidepressants. This systematic review highlights the need for studies systematically investigating this phenomenon and associated risk factors.

Drug treatment of depression: reflections on the evidence

Guidelines are readily available for the treatment of depression, and more recent ones are explicitly evidence-based. Their core messages vary little but they tend to minimise uncertainties and gloss over difficult areas. This article examines three areas of uncertainty: the thresholds of severity and, for milder depression, the duration of illness for which antidepressants are more effective than placebo; the next step in drug treatment when a patient has failed to respond adequately to a first antidepressant; and how long continuing on antidepressants should be recommended in relation to individual patients' needs. It is concluded that the uncertainties in relation to treating individual patients are a combination of lack of evidence and individual patient factors but there is also an intrinsic uncertainty that will continue to require good clinical judgement.

Treatment and Prevention of Depression

Depression is one of the most common and debilitating psychiatric disorders and is a leading cause of suicide. Most people who become depressed will have multiple episodes, and some depressions are chronic. Persons with bipolar disorder will also have manic or hypomanic episodes. Given the recurrent nature of the disorder, it is important not just to treat the acute episode, but also to protect against its return and the onset of subsequent episodes.

Several types of interventions have been shown to be efficacious in treating depression. The antidepressant medications are relatively safe and work for many patients, but there is no evidence that they reduce risk of recurrence once their use is terminated. The different medication classes are roughly comparable in efficacy, although some are easier to tolerate than are others. About half of all patients will respond to a given medication, and many of those who do not will respond to some other agent or to a combination of medications. Electro-convulsive therapy is particularly effective for the most severe and resistant depressions, but raises concerns about possible deleterious effects on memory and cognition. It is rarely used until a number of different medications have been tried.

Although it is still unclear whether traditional psychodynamic approaches are effective in treating depression, interpersonal psychotherapy (IPT) has fared well in controlled comparisons with medications and other types of psychotherapies. It also appears to have a delayed effect that improves the quality of social relationships and interpersonal skills. It has been shown to reduce acute distress and to prevent relapse and recurrence so long as it is continued or maintained. Treatment combining IPT with medication retains the quick results of pharmacotherapy and the greater interpersonal breadth of IPT, as well as boosting response in patients who are otherwise more difficult to treat. The main problem is that IPT has only recently entered clinical practice and is not widely available to those in need.

Cognitive behavior therapy (CBT) also appears to be efficacious in treating depression, and recent studies suggest that it can work for even severe depressions in the hands of experienced therapists. Not only can CBT relieve acute distress, but it also appears to reduce risk for the return of symptoms as long as it is continued or maintained. Moreover, it appears to have an enduring effect that reduces risk for relapse or recurrence long after treatment is over. Combined treatment with medication and CBT appears to be as efficacious as treatment with medication alone and to retain the enduring effects of CBT. There also are indications that the same strategies used to reduce risk in psychiatric patients following successful treatment can be used to prevent the initial onset of depression in persons at risk. More purely behavioral interventions have been studied less than the cognitive therapies, but have performed well in recent trials and exhibit many of the benefits of cognitive therapy.

Mood stabilizers like lithium or the anticonvulsants form the core treatment for bipolar disorder, but there is a growing recognition that the outcomes produced by modern pharmacology are not sufficient. Both IPT and CBT show promise as adjuncts to medication with such patients. The same is true for family-focused therapy, which is designed to reduce interpersonal conflict in the family. Clearly, more needs to be done with respect to treatment of the bipolar disorders.

Good medical management of depression can be hard to find, and the empirically supported psychotherapies are still not widely practiced. As a consequence, many patients do not have access to adequate treatment. Moreover, not everyone responds to the existing interventions, and not enough is known about what to do for people who are not helped by treatment. Although great strides have been made over the past few decades, much remains to be done with respect to the treatment of depression and the bipolar disorders.

WITHDRAWN: Drugs versus placebo for dysthymia

This review has been withdrawn due to non‐compliance with Cochrane's Commercial Sponsorship Policy.

The editorial group responsible for this previously published document have withdrawn it from publication.

The clinical pharmacology of depressive states

Antidepressants have good efficacy in the treatment of mood disorders, with effect sizes that have consistently been found to be greater than those of placebo. The more recent antidepressants do not have better efficacy than the compounds discovered 40 to 50 years ago, but they do have a more favorable configuration of side effects, leading to fewer dropouts. This favorable situation has made it possible to prescribe the newer antidepressants in less severe depression and in several anxiety disorders, with considerable benefit to patients. During the last decades, research into the pathophysiology of mood and anxiety disorders has provided much information on the brain circuitry, neurohormones, and neurotransmitters involved in these disorders. In parallel, biological and behavioral work on antidepressants, using animal models and new biochemical techniques, has led to a broader understanding of the mode of action of these drugs. Despite this impressive list of discoveries, much research remains to be done on the clinical, psychological, neuropsychological, physiological, and neurochemical aspects, before we can obtain a coherent description of the pathophysiological mechanisms of depression and its treatment. This will lead to a better ability to predict the quality of drug response and, therefore, to the individualization of treatment.

High-dose glycine treatment of refractory obsessive-compulsive disorder and body dysmorphic disorder in a 5-year period

This paper describes an individual who was diagnosed with obsessive-compulsive disorder (OCD) and body dysmorphic disorder (BDD) at age 17 when education was discontinued. By age 19, he was housebound without social contacts except for parents. Adequate trials of three selective serotonin reuptake inhibitors, two with atypical neuroleptics, were ineffective. Major exacerbations following ear infections involving Group A β-hemolytic streptococcus at ages 19 and 20 led to intravenous immune globulin therapy, which was also ineffective. At age 22, another severe exacerbation followed antibiotic treatment for H. pylori. This led to a hypothesis that postulates deficient signal transduction by the N-methyl-D-aspartate receptor (NMDAR). Treatment with glycine, an NMDAR coagonist, over 5 years led to robust reduction of OCD/BDD signs and symptoms except for partial relapses during treatment cessation. Education and social life were resumed and evidence suggests improved cognition. Our findings motivate further study of glycine treatment of OCD and BDD.

Time to relapse after short- or long-term treatment of severe premenstrual syndrome with sertraline

CONTEXT

The duration of treatment after achieving a satisfactory response is unknown in the treatment of premenstrual syndrome. This information is needed in view of the improvement provided by medication vs the adverse effects and costs of drugs.

OBJECTIVE

To compare rates of relapse and time to relapse between short- and long-term treatment with sertraline hydrochloride administered in the luteal phase of the menstrual cycle.

DESIGN

Eighteen-month survival study with a randomized double-blind switch to placebo after 4 or 12 months of sertraline treatment.

SETTING

Academic medical center.

PARTICIPANTS

One hundred seventy-four patients with premenstrual syndrome or premenstrual dysphoric disorder.

MAIN OUTCOME MEASURE

Relapse, defined as symptoms returning to the entry criterion level as assessed with daily ratings.

RESULTS

The relapse rate was 41% during long-term treatment compared with 60% after short-term sertraline therapy, with a median time to relapse of 8 months vs 4 months (hazard ratio, 0.58; 95% confidence interval, 0.34-0.98; P = .04). Patients with severe symptoms at baseline were more likely to experience relapse compared with patients in the lower symptom severity group (hazard ratio, 2.02; 95% confidence interval, 1.18-3.41; P = .01) and were more likely to experience relapse with short-term treatment (P = .03). Duration of treatment did not affect relapse in patients in the lower symptom severity group (P = .50). Patients who demonstrated remission were least likely to experience relapse (hazard ratio, 0.22; 95% confidence interval, 0.10-0.45; P < .001). Further analysis comparing relapse in the first 6 months of placebo treatment in each group yielded similar results.

CONCLUSIONS

The relapse rate was significantly greater after short-term treatment compared with long-term treatment. The relapse rate was also high during extended drug treatment. Subjects with severe symptoms at baseline were most likely to experience relapse, and relapse occurred more swiftly regardless of treatment duration. These findings suggest that the severity of symptoms at baseline and symptom remission with treatment should be considered in determining the duration of treatment.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00318773.

The persistence of the placebo response in antidepressant clinical trials

Our objective was to assess the persistence of the placebo response during at least 12 weeks of continued placebo administration in depressed patients who have responded to 6-8 weeks of acute placebo treatment. We identified 8 placebo-controlled antidepressant trials with a total of 3,063 depressed patients in which, after acute phase placebo treatment, placebo was continued for more than 12 weeks. The number of patients entering the continuation phase and percentages relapsing during this phase were determined. Based on the total number of patients entering the continuation phase 79% of placebo responders remained well (did not meet relapse criteria) during this phase compared to 93% of antidepressant responders. Although significantly more patients on placebo than on antidepressants relapsed in the continuation phase, 4 out of 5 placebo responders stayed well. The widely held belief that the placebo response in depression is short-lived appears to be based largely on intuition and perhaps wishful thinking.

A controlled trial of paroxetine for chronic PTSD, dissociation, and interpersonal problems in mostly minority adults

This study evaluated the efficacy of paroxetine for symptoms and associated features of chronic posttraumatic stress disorder (PTSD), interpersonal problems, and dissociative symptoms in an urban population of mostly minority adults. Adult outpatients with a primary DSM-IV diagnosis of chronic PTSD received 1 week of single-blind placebo (N = 70). Those not rated as significantly improved were then randomly assigned to placebo (N = 27) or paroxetine (N = 25) for 10 weeks, with a flexible dosage design (maximum 60 mg by week 7). Significantly more patients treated with paroxetine were rated as responders (14/21, 66.7%) on the Clinical Global Impression-Improvement Scale (CGI-I) compared to patients treated with placebo (6/22, 27.3%). Mixed effects models showed greater reductions on the Clinician-Administered PTSD Scale (CAPS) total score (primary plus associated features of PTSD) in the paroxetine versus placebo groups. Paroxetine was also superior to placebo on reduction of dissociative symptoms [Dissociative Experiences Scale (DES) score] and reduction in self-reported interpersonal problems [Inventory of Interpersonal Problems (IIP) score]. In a 12-week maintenance phase, paroxetine response continued to improve, but placebo response did not. Paroxetine was well tolerated and superior to placebo in ameliorating the symptoms of chronic PTSD, associated features of PTSD, dissociative symptoms, and interpersonal problems in the first trial conducted primarily in minority adults.

A typological model for estimation of drug and placebo effects in depression

One reason for failure to find specific treatment effects in drug versus placebo trials with patients who have depression is an insufficient period of observation. Also, differentiating between early fleeting response and maintained response has been shown relevant to detecting specific drug action. A model in which various types of drug and placebo response are specifically stipulated and which takes advantage of a two-stage experimental design is proposed. Substantive findings when patients who have major depression with atypical features are studied are: 1) about 6% have only a fleeting response to placebo and no response to drug; 2) by week-10 about 28% of the population will respond even if no medication is given; and 3) specific response to imipramine (21%) can be determined by week-4 but specific response to fluoxetine (20%) cannot be determined until later (week-10 in this study).

Vagus nerve stimulation (VNS) for major depressive episodes: one year outcomes

BACKGROUND

Vagus nerve stimulation has shown promising results in an open, acute phase pilot study of adults in a treatment-resistant major depressive episode. This open, naturalistic follow-up study was conducted to determine whether the initial promising effects were sustained, and whether changes in function would be observed.

METHODS

Thirty adult outpatients in a treatment-resistant, nonpsychotic major depressive episode received an additional 9 months of vagus nerve stimulation treatment following exit from the 3-month acute study. Changes in psychotropic medications and vagus nerve stimulation stimulus parameters were allowed during this longer-term follow-up study. A priori definitions were used to define response (> or = 50% reduction in baseline Hamilton Rating Scale for Depression total score) and remission (Hamilton Rating Scale for Depression < or = 10).

RESULTS

The response rate was sustained [40% (12/30) to 46% (13/28); p =.317] and the remission rate significantly increased [17% (5/30) to 29% (8/28); p =.045] with an additional 9 months of long-term vagus nerve stimulation treatment after exit from the acute study (1 year total vagus nerve stimulation treatment). Significant improvements in function between acute study exit and the 1-year follow-up assessment as measured by the Medical Outcomes Study Short Form-36 were observed.

CONCLUSIONS

Longer-term vagus nerve stimulation treatment was associated with sustained symptomatic benefit and sustained or enhanced functional status in this naturalistic follow-up study.

Loss of response to antidepressants and subsequent refractoriness: diagnostic issues in a retrospective case series

BACKGROUND

The loss of response to antidepressant drugs is not an uncommon phenomenon. While some patients respond to changes in the drug regimen, others develop resistance to various treatment modalities.

METHOD

I describe 15 cases who had a loss of response to repeated trials of antidepressants before developing a chronic and severe, refractory depression.

RESULTS

These patients had failed to respond to various treatment strategies including substitution with other antidepressant drugs, augmentation with agents such as T3 and lithium; and finally electroconvulsive therapy (ECT). Following discontinuation of antidepressants and treatment with mood stabilizers, there was a sustained improvement. Notably some of the patients who had earlier failed to respond to mood stabilizers in combination with unimodal antidepressants improved upon discontinuation of antidepressants and continued treatment with mood stabilizers.

LIMITATIONS

Open trial, retrospective design and small sample size.

CONCLUSION

These clinical findings suggest that some refractory depressives represent cryptic bipolar disorders. Prospective validation is necessary to support this conclusion.

Depressive breakthrough

Controlled studies of continuation and maintenance pharmacotherapy have consistently shown the advantage of drug therapy over placebo for the prevention of relapses and recurrences, particularly when antidepressant medications are maintained at the full dose required initially to establish remission. Nevertheless, controlled and observational studies indicate substantial rates of relapse and recurrence despite long-term treatment. Although depressive breakthrough is a common clinical problem, few uncontrolled studies and no controlled trials are available on management of depressive breakthrough. Three principal pharmacologic strategies seem to be (1) increasing dose, (2) adding another agent, and (3) switching antidepressants. Controlled studies of long-term treatment are needed to identify the optimal nature and sequence of approaches for re-emergent depression and to determine what symptom severity and duration should prompt the initiation of treatment.

A comparison of drugs versus placebo for the treatment of dysthymia

OBJECTIVES

Dysthymia is a depressive disorder of chronic nature but of less severity than major depression, which depressive symptoms are more or less continuous for at least two years. The aim of this review was to conduct a systematic review of all RCTs comparing drugs and placebo for dysthymia.

SEARCH STRATEGY

Electronic searches of Cochrane Library, EMBASE, MEDLINE, PsycLIT, Biological Abstracts and LILACS; reference searching; personal communication; conference abstracts; unpublished trials from the pharmaceutical industry; book chapters on the treatment of depression.

SELECTION CRITERIA

The inclusion criteria for all randomised controlled trials were that they should focus on the use of drugs versus placebo for dysthymic patients. Exclusion criteria were: non randomised, mixed major depression/ dysthymia (trials not providing separate data) and depression secondary to other disorders (e.g. substance abuse).

DATA COLLECTION AND ANALYSIS

The reviewers extracted the data independently. In order to achieve an intention-to-treat analysis, when trials failed to report it was assumed that people who died or dropped out had no improvement. Authors of relevant trials were contacted for additional and missing data. Absence of treatment response as defined by authors was the main measure of outcome used. Relative Risks (RR) and 95% confidence intervals (CI) of dichotomous data were calculated with the Random Effects Model. Where possible, number needed to treat (NNT) and number needed to harm (NNH) were estimated, taking the reciprocal of the absolute risk reduction.

MAIN RESULTS

Currently the review includes 15 trials. Similar results were obtained in terms of efficacy for different groups of drugs, such as tricyclic (TCA), selective serotonin reuptake inhibitors (SSRI), monoamine oxidase inhibitors (MAOI) and other drugs (sulpiride, amineptine, and ritanserin). The pooled RR for absence of treatment response was 0. 68 (95% CI 0.59-0.78) for TCA and the NNT was 4.3 (95% CI 3.2-6.5). SSRIs showed similar RR for this outcome: 0.64 (95% CI 0.55-0.74), the NNT being 4.7 (95% CI 3.5-6.9). Concerning MAOIs, the RR was 0. 59 (95% CI 0.48-0.71) and the NNT was 2.9 (95% CI 2.2-4.3). Other drugs (amisulpride, amineptine and ritanserin) showed similar results in terms of absence of treatment response. Using more stringent criteria for improvement - full remission - the results were unchanged. Patients treated on TCA were more likely to report adverse events, compared with placebo.

REVIEWER'S CONCLUSIONS

Drugs are effective in the treatment of dysthymia with no differences between and within class of drugs. Tricyclic antidepressants are more likely to cause adverse events and dropouts. As dysthymia is a chronic condition, there remains little information on quality of life and medium or long-term outcome.

A Canadian multicentre placebo-controlled study of a fixed dose of brofaromine, a reversible selective MAO-A inhibitor, in the treatment of major depression

In a 6-week double-blind study, 220 patients with major depression (mostly outpatients) were randomly assigned to receive a fixed dose of brofaromine 150 mg daily (n = 111) or placebo (n = 109) after a 1-week single-blind placebo washout. Except for the HAM-D sleep items, brofaromine was superior to placebo on measures of depression as determined by the four methods of assessing drug efficacy: (1) psychiatric symptom rating (HAM-D 17-item less the three sleep items); (2) self-rating scale (Beck Depression Inventory); (3) Clinical Global Assessment of Efficacy; and (4) drop-out rate due to lack of efficacy. Most commonly reported adverse events with brofaromine were: headache, nausea, dizziness and sleep disturbance. Brofaromine was found to be an effective antidepressant, superior to placebo with a good tolerability profile.