Moderation of antidepressant and placebo outcomes by baseline severity in late-life depression: A systematic review and meta-analysis

Re-thinking the treatment of depression: have we been misinformed about antidepressants? A webinar discussion with Irving Kirsch, Ph.D. and Michael D. Yapko, Ph.D

This article provides an edited transcript of a moderated discussion between depression experts Irving Kirsch and Michael Yapko regarding the role of antidepressants in the treatment of major depression. It includes references to the role of expectancy and the merits of hypnosis in treatment. This presentation was sponsored by MindsetHealth, an Australian-based digital therapeutics company (mindsethealth.com) and took place online on March 28, 2023. As a webinar offered at no cost, it was open to anyone with an interest in the subject. Dr. Kirsch described his landmark research on the placebo effect and its curious relationship to the presumed merits of antidepressant medications. Dr. Yapko discussed the limitations of drug treatment based on the substantial evidence indicating that depression is much more a social problem than a medical one. The moderator for this discussion is Claire Davidson, who serves as the Research Lead at MindsetHealth. Drs. Kirsch and Yapko both serve on the MindsetHealth Scientific Advisory Board.

Treatment strategy for late-life depression

With the unprecedented aging of the world's population, the number of elderly patients with depression is expected to increase. However, management and treatment of late-life depression (LLD) is more difficult than in early adults. Prior to treatment, diagnosis must take into account the differentiation from, and comorbidity with, organic brain diseases such as dementia and delirium, as well as depression caused by other physical diseases or medications. As clinical features of LLD, treatment response tends to be poor in older patients and recurrence rates are higher than those in early adult patients, therefore psycho-social interventions on the basis of the patient's background and condition are important for LLD. The first-line treatment strategy generally depends on the severity of the depression. Systematic psychotherapies, including cognitive behavioral therapy and problem-solving therapy, have been reported to reduce depressive symptoms in LLD. Regarding pharmacotherapy, newer antidepressants are recommended for LLD, but careful attention to adverse events is required. Treatment using neuromodulation is also reported to be useful for LLD. In the current review, for further-line treatment, treatment strategies were divided according to the level of first-line treatment response. Evidence indicates that LLD is more heterogeneous than depression in younger adults, therefore when treating LLD patients it is necessary to take various conditions and situations into consideration, and to provide detailed treatment that is tailored to each patient.

Impact of gender, depression severity and type of depressive episode on efficacy and safety of escitalopram: an observational study on major depressive disorder patients in southern India

Background

Antidepressant response is a complex trait influenced by clinical, demographic and genetic factors.

Objectives

To explore the influences of baseline depression severity, gender and type of depressive episode on efficacy and safety of escitalopram (10–20 mg/day) in South Indian patients with major depressive disorder (MDD).

Methods

The study was conducted on 18–65-year-old patients (n = 151) suffering from a first or recurrent episode of MDD with a 17-item Hamilton Depression Rating Scale (HDRS-17) score of ≥ 18 at baseline. Efficacy assessments were done using HDRS-17, Montgomery-Asberg Depression Rating Scale (MADRS), and Clinical Global Impression (CGI) at baseline and weeks 4, 8 and 12. Patients were monitored for adverse drug reactions (ADRs). Clinical outcomes were compared among various groups based on gender, type of depressive episode (first or recurrent episode) and baseline HDRS-17 scores (moderate depression—score between 17 and 23; severe depression—score ≥ 24).

Results

Among the 148 subjects who completed the 12-week study, 43.9% and 42.6% achieved response and remission, respectively. The decline in HDRS-17 and MADRS scores from baseline was significant (p value < 0.05) at all follow-up visits and a similar pattern was seen with CGI. Efficacy outcomes were better in the moderate baseline depression group compared with severe depression. There were no associations of efficacy with gender and type of depressive episode. A total of 247 adverse drug reactions (ADR) were reported and 119 (80.41%) subjects experienced at least one ADR during the study period. No serious ADR was reported. Male patients experienced more ADRs compared with females. The safety profile of escitalopram was similar across various groups based on baseline depression severity and type of depressive episode.

Conclusion

The study revealed that escitalopram is efficacious in south Indian MDD patients with a favourable safety profile. The efficacy was influenced by baseline depression severity whereas more ADRs were reported by male patients.

Depression in post-traumatic stress disorder

Major depressive disorder (MDD) symptoms commonly occur after trauma-exposure, both alone and in combination with post-traumatic stress disorder (PTSD). This article reviews recent research on comorbidity between these disorders, including its implications for symptom severity and response to treatment. Despite considerable symptom overlap, the two disorders represent distinct constructs and depend, at least in part, on separate biological mechanisms. Both, however, are also clearly related to stress psychopathology. We recommend that more research focus specifically on the study of individual differences in symptom expression in order to identify distinct subgroups of individuals and develop targeted treatments. However, a barrier to this line of inquiry is the trend of excluding particular patients from clinical trials of new interventions based on symptom severity or comorbidity. Another obstacle is the overreliance on self-report measures in human research. We argue that developing computer-based behavioral measures in order to supplement self-report can help address this challenge. Furthermore, we propose that these measures can help tie findings from human and non-human animal research. A number of paradigms have been used to model MDD-and PTSD-like behavior in animals. These models remain valuable for understanding the biological basis of these disorders in humans and for identifying potential interventions, but they have been underused for the study of comorbidity. Although the interpretation of animal behavior remains a concern, we propose that this can also be overcome through the development of close human analogs to animal paradigms.

Efficacy of light therapy for a college student sample with non-seasonal subthreshold depression: An RCT study

BACKGROUND

Light therapy has been successfully used to treat seasonal and non-seasonal depression, but there is limited evidence for its efficacy in subthreshold depression. This study examines the efficacy of light therapy for symptoms of depression and anxiety in non-seasonal subthreshold depression.

METHODS

College students with non-seasonal subthreshold depression were recruited. The participants were randomly allocated to one of the three conditions: high- (LT-5000 lux) and low-intensity (LT-500 lux) light therapy conditions and a waiting-list control condition (WLC). The primary outcome was Hamilton Depression Rating Scale (HAMD), and secondary outcomes were Beck Depression Inventory-II (BDI-II) and state anxiety inventory (SAI), which were assessed at baseline (Week 0), during the trial (Week 4), and after completion of the light therapy (Week 8).

RESULTS

A total of 142 participants completed the trial. The LT-5000 (effect size [d] = 1.56, 95% CI: 1.15 to 1.98) and LT-500 conditions (d = 0.84, 95% CI: 0.43 to 1.26) were significantly superior to the WLC condition. For the LT-5000, LT-500, and WLC conditions by the end of the 8-week trial, a response on the HAMD was achieved by 70.0%, 42.0% and 19.0% of the participants, and remission was achieved by 76.0%, 54.0%, and 19.0%, respectively.

LIMITATIONS

The subjects were not followed up regularly after completion of the trial.

CONCLUSION

Light therapy, both at high- and low-intensity, was efficacious in the treatment of college students with non-seasonal subthreshold depression. High-intensity light therapy was superior to low-intensity light therapy by the end of an 8-week trial.

Depression in Alzheimer's Disease: An Alternative Role for Selective Serotonin Reuptake Inhibitors?

Depression is a common co-morbidity seen in people with Alzheimer's disease (AD). However, the successful treatment of depressive symptoms in people with AD is rarely seen. In fact, multiple randomized controlled trials have shown selective serotonin reuptake inhibitors (SSRIs), the current best recommended treatment for depression, to be ineffective in treating depressive symptoms in people with AD. One explanation for this lack of treatment effect may be that depressive symptoms can reflect the progression of AD, rather than clinical depression and are a consequence of more severe neurodegeneration. This raises several questions regarding not only the efficacy of SSRIs in the treatment of depression in people with AD but also regarding the accuracy of diagnosis of depression in AD. However, there may be a rationale for the prescription of SSRIs in early AD. Even in the absence of depression, SSRIs have been shown to slow the conversion from mild cognitive impairment to AD. This may be attributed to the effect of SSRIs on the processing of amyloid-β precursor protein, which may cause a reduction in the accumulation of amyloid-β. Thus, although SSRIs may lack efficacy in treating depression in people with AD, they may hold therapeutic potential for treating and delaying the progression of AD especially if treatment begins in the early stages of AD. This article reviews the current consensus for SSRI treatment of depression in people with AD and highlights the possibility of SSRIs being a treatment option for delaying the progression of AD.

Optimal doses of antidepressants in dependence on age: Combined covariate actions in Bayesian network meta-analysis

Background: The meta-analysis by Furukawa et al. (The Lancet Psychiatry 2019, 6(7)) reported optimal doses for antidepressants in adult major depressive disorder (MDD). The present reanalysis aimed to adjust optimal doses in dependence on age. Methods: Analysis was based on the same dataset by Cipriani et al. (The Lancet 2018, 391(10128)) comparing 21 antidepressants in MDD. Random-effects Bayesian network meta-analysis was implemented to estimate the combined covariate action using restricted cubic splines (RCS). Balanced treatment recommendations were derived for the outcomes efficacy (response), acceptability (dropouts for any reason), and tolerability (dropouts due to adverse events). Findings: The combined covariate action of dose and age suggested agomelatine and escitalopram as the best-balanced antidepressants in terms of efficacy and tolerability that may be escalated until 40 and 60 mg/day fluoxetine equivalents (mg/day FE ), respectively, for ages 30-65 years. Desvenlafaxine, duloxetine, fluoxetine, milnacipran, and vortioxetine may be escalated until 20-40 mg/day FE , whereas bupropion, citalopram, mirtazapine, paroxetine, and venlafaxine may not be given in doses  > 20 mg/day FE . Amitriptyline, clomipramine, fluvoxamine, levomilnacipran, reboxetine, sertraline, and trazodone revealed no relevant balanced benefits and may therefore not be recommended for antidepressant treatment. None of the antidepressants was observed to provide balanced benefits in patients >70 years because of adverse events exceeding efficacy. Interpretation: Findings suggest that the combined covariate action of dose and age provides a better basis for judging antidepressant clinical benefits than considering dose or age separately, and may thus inform decision makers to accurately guide antidepressant dosing recommendations in MDD. Funding: No funding.

Combining threshold analysis and GRADE to assess sensitivity to bias in antidepressant treatment recommendations adjusted for depression severity

Threshold analysis has recently been proposed to be used in combination with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) in order to assess the sensitivity to plausible bias of treatment recommendations derived from Bayesian network meta-analysis (NMA). Here, it was aimed to apply the combination of threshold analysis and GRADE to judge quantitative and qualitative information on risk of bias in antidepressant treatment recommendations. The analysis was based on the data set provided by Cipriani et al. (The Lancet 2018) comparing 21 antidepressants in adult major depressive disorder (MDD). Primary outcomes were efficacy (response rate) and acceptability (dropout rate) adjusted for the covariate depression severity. The combined approach suggested sensitivity to plausible bias to be largest for antidepressant recommendations top ranked by Cipriani et al., that is, amitriptyline, duloxetine, paroxetine, and venlafaxine in terms of efficacy and agomelatine, escitalopram, paroxetine, and venlafaxine in terms of acceptability. Covariate ranges within which recommendations were most sensitive to plausible bias were very severe depression in terms of efficacy (smallest threshold, ie, the largest sensitivity, around 39 Hamilton Depression Rating Scale [HDRS]) and moderate depression in terms of acceptability (smallest thresholds around 16 and 35 HDRS). This indicates that treatment recommendations within these ranges may likely change if plausible bias adjustments take place. The present findings may support decision makers in judging the sensitivity to plausible bias of current antidepressant treatment recommendations to accurately guide treatment decisions in MDD depending on depression severity.

The placebo and its effects: A psychoneuroendocrinological perspective

Placebos are usually employed deceptively in clinical trials in order to control for non-specific effects. However, since placebos themselves have been found to cause clinically relevant changes and in some cases are indistinguishable from the verum they are tested against, this theoretically inert, but practically effective intervention has become a scientific discipline in its own right. In this review, it is argued that placebos are generic and genuine biopsychosocial interventions and as such are highly interesting candidates for a psychoneuroendocrinological perspective. Yet, despite a considerable conceptual proximity between explanatory models of placebos and their effects with psychoneuroendocrine models and findings, placebos have thus far not been subject to systematic psychoneuroendocrine examination. Consequently, it would be highly interesting and informative to make placebos the target of psychoneuroendocrine scrutiny.

Predictors of treatment outcome in depression in later life: A systematic review and meta-analysis

BACKGROUND

Predictor analyses of late-life depression can be used to identify variables associated with outcomes of treatments, and hence ways of tailoring specific treatments to patients. The aim of this review was to systematically identify, review and meta-analyse predictors of outcomes of any type of treatment for late-life depression.

METHODS

Pubmed, Embase, CINAHL, Web of Science and PsycINFO were searched for studies published up to December 2016. Primary and secondary studies reported treatment predictors from randomised controlled trials of any treatment for patients with major depressive disorder aged over 60 were included. Treatment outcomes included response, remission and change in depression score.

RESULTS

Sixty-seven studies met the inclusion criteria. Of 65 identified statistically significant predictors, only 7 were reported in at least 3 studies. Of these, 5 were included in meta-analyses, and only 3 were statistically significant. Most studies were rated as being of moderate to strong quality and satisfied key quality criteria for predictor analyses.

LIMITATIONS

The searches were limited to randomised controlled trials and most of the included studies were secondary analyses.

CONCLUSIONS

Baseline depression severity, co-morbid anxiety, executive dysfunction, current episode duration, early improvement, physical illnesses and age were reported as statistically significant predictors of treatment outcomes. Only the first three were significant in meta-analyses. Subgroup analyses showed differences in predictor effect between biological and psychosocial treatment. However, high heterogeneity and small study numbers suggest a cautious interpretation of results. These predictors were associated with various mechanisms including brain pathophysiology, perceived social support and proposed distinct types of depressive disorder. Further investigation of the clinical utility of these predictors is suggested.

Initial symptom severity of bipolar I disorder and the efficacy of olanzapine: a meta-analysis of individual participant data from five placebo-controlled studies

BACKGROUND

The efficacy of antipsychotics across the initial severity range in patients with acute mania remains unclear. Therefore, we examined the influence of baseline severity on the efficacy of olanzapine.

METHODS

We did an individual participant data meta-analysis of double-blind, randomised controlled trials that compared olanzapine with placebo, identified through searches of the ClinicalStudyRequest.com database on Feb 2, 2016. We included patients with acute mania associated with bipolar I disorder. We examined the association between baseline and change scores on the Young Mania Rating Scale (YMRS; range 0-60) up to 3 weeks for olanzapine versus placebo groups using eight increasingly complex competing mixed-effects models for repeated measures.

FINDINGS

We identified 33 reports, five (15%) of which were eligible and contained data for 939 patients (552 received olanzapine; 387 received placebo). The interaction between baseline severity and treatment was significant (β=0·22, 95% CI 0·05-0·39; p=0·013). The greater the baseline severity, the greater the magnitude of the differences between olanzapine and placebo was expected. The mean estimated YMRS scores were reduced at 3 weeks in both groups, but were greater with olazapine than placebo by 2·56 points for patients with a baseline score of 20-25 (9·26 for olanzapine vs 6·70 for placebo; effect size 0·35, 95% CI 0·11-0·60), by 4·74 points for a baseline score of 25-35 (14·25 vs 9·51; 0·58, 0·34-0·86), and by 8·01 points for a baseline score of 35-60 (21·72 vs 13·71; 0·70, 0·31-1·23).

INTERPRETATION

Benefits of olanzapine can be expected for patients across the full spectrum of symptom severity who are likely to be treated for acute mania. Less severely ill patients seem to benefit less in terms of olanzapine efficacy, but still experience the same side-effects as more severely ill patients. Thus, clinicians and patients should carefully consider the benefit-to-risk ratio of olanzapine and its additional, prophylactic effect against relapse in the long term. The generalisability of these results to other antipsychotics, trial designs, and medical conditions remains to be established.

FUNDING

None.

Caregiver placebo effect in analgesic clinical trials for cats with naturally occurring degenerative joint disease-associated pain

A literature review identified six placebo-controlled studies of analgesics in client-owned cats with degenerative joint disease-associated pain. Five studies with 96 cats had available data. Caregiver responses on a clinical metrology instrument, Client-Specific Outcome Measure (CSOM), were compared to measured activity. Cats were categorised as 'successes' or 'failures' based on change in CSOM score and activity counts from baseline. Effect sizes based on CSOM score were calculated; factors that were associated with success/failure were analysed using logistic regression. Effect sizes ranged from 0.97 to 1.93. The caregiver placebo effect was high, with 54-74 per cent of placebo-treated cats classified as CSOM successes compared with 10-63 per cent of cats classified as successes based on objectively measured activity. 36 per cent of CSOM successes were also activity successes, while 19 per cent of CSOM failures were activity successes. No significant effects of cat age, weight, baseline activity, radiographic score, orthopaedic pain score or study type on CSOM success in the placebo groups were found. The caregiver placebo effect across these clinical trials was remarkably high, making demonstration of efficacy for an analgesic above a placebo difficult. Further work is needed to determine whether a potential placebo-by-proxy effect could benefit cats in clinical settings.

Geriatric characteristics in randomised controlled trials on antidepressant drugs for older adults: a systematic review

OBJECTIVE

Meta-analyses of antidepressant drug treatment trials have found that increasing age is associated with a less favourable outcome. Because the prevalence of geriatric characteristics, like disability, medical co-morbidity, malnutrition, cognitive (dys)function and frailty increase with age and are associated with depression, these characteristics are likely to modify the treatment outcome of antidepressant drugs in late-life depression. This review examines how these five characteristics are taken into account in randomised controlled trials (RCTs) with antidepressant drugs for major depressive disorder in patients aged 60 years or above.

DESIGN

A systematic search in PubMED, PsychInfo and EMBASE, from the year 2000 onwards, yielded 27 RCTs, with a total of 6356 subjects with a median age of 71 years. Two reviewers independently assessed whether each characteristic was considered as inclusion or exclusion criterion, descriptive variable, stratification variable, co-variable, outcome measure, or in adverse effect monitoring.

RESULTS

Malnutrition and frailty were not taken into account in any study. Disability was used as an outcome measure in five studies. Two studies explicitly included a population with possibly serious medical co-morbidity. Cognitive status was the only condition taken into account as co-variable (n = 3) or stratifying variable (n = 1) and was used as outcome measure in seven studies.

CONCLUSIONS

We conclude that geriatric characteristics are rarely taken into account in RCTs on antidepressant drugs in late-life depression, and studies including the oldest adults are underrepresented. This warrants recruitment of the oldest adults and adjustment of treatment strategies in future studies. Copyright © 2016 John Wiley & Sons, Ltd.