Placebo for depression: we need to improve the quality of scientific information but also reject too simplistic approaches or ideological nihilism

Cortical Connectivity Moderators of Antidepressant vs Placebo Treatment Response in Major Depressive Disorder: Secondary Analysis of a Randomized Clinical Trial

IMPORTANCE

Despite the widespread awareness of functional magnetic resonance imaging findings suggesting a role for cortical connectivity networks in treatment selection for major depressive disorder, its clinical utility remains limited. Recent methodological advances have revealed functional magnetic resonance imaging-like connectivity networks using electroencephalography (EEG), a tool more easily implemented in clinical practice.

OBJECTIVE

To determine whether EEG connectivity could reveal neural moderators of antidepressant treatment.

DESIGN, SETTING, AND PARTICIPANTS

In this nonprespecified secondary analysis, data were analyzed from the Establishing Moderators and Biosignatures of Antidepressant Response in Clinic Care study, a placebo-controlled, double-blinded randomized clinical trial. Recruitment began July 29, 2011, and was completed December 15, 2015. A random sample of 221 outpatients with depression aged 18 to 65 years who were not taking medication for depression was recruited and assessed at 4 clinical sites. Analysis was performed on an intent-to-treat basis. Statistical analysis was performed from November 16, 2018, to May 23, 2019.

INTERVENTIONS

Patients received either the selective serotonin reuptake inhibitor sertraline hydrochloride or placebo for 8 weeks.

MAIN OUTCOMES AND MEASURES

Electroencephalographic orthogonalized power envelope connectivity analyses were applied to resting-state EEG data. Intent-to-treat prediction linear mixed models were used to determine which pretreatment connectivity patterns were associated with response to sertraline vs placebo. The primary clinical outcome was the total score on the 17-item Hamilton Rating Scale for Depression, administered at each study visit.

RESULTS

Of the participants recruited, 9 withdrew after first dose owing to reported adverse effects, and 221 participants (150 women; mean [SD] age, 37.8 [12.7] years) underwent EEG recordings and had high-quality pretreatment EEG data. After correction for multiple comparisons, connectome-wide analyses revealed moderation by connections within and between widespread cortical regions-most prominently parietal-for both the antidepressant and placebo groups. Greater alpha-band and lower gamma-band connectivity predicted better placebo outcomes and worse antidepressant outcomes. Lower connectivity levels in these moderating connections were associated with higher levels of anhedonia. Connectivity features that moderate treatment response differentially by treatment group were distinct from connectivity features that change from baseline to 1 week into treatment. The group mean (SD) score on the 17-item Hamilton Rating Scale for Depression was 18.35 (4.58) at baseline and 26.14 (30.37) across all time points.

CONCLUSIONS AND RELEVANCE

These findings establish the utility of EEG-based network functional connectivity analyses for differentiating between responses to an antidepressant vs placebo. A role emerged for parietal cortical regions in predicting placebo outcome. From a treatment perspective, capitalizing on the therapeutic components leading to placebo response differentially from antidepressant response should provide an alternative direction toward establishing a placebo signature in clinical trials, thereby enhancing the signal detection in randomized clinical trials.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01407094.

Internet-Delivered Cognitive Behavioural Therapy for Major Depression and Anxiety Disorders: A Health Technology Assessment

BACKGROUND

Major depression is defined as a period of depression lasting at least 2 weeks characterized by depressed mood, most of the day, nearly every day, and/or markedly diminished interest or pleasure in all, or almost all, activities. Anxiety disorders encompass a broad range of disorders in which people experience feelings of fear and excessive worry that interfere with normal day-to-day functioning.Cognitive behavioural therapy (CBT) is a form of evidence-based psychotherapy used to treat major depression and anxiety disorders. Internet-delivered CBT (iCBT) is structured, goal-oriented CBT delivered via the internet. It may be guided, in which the patient communicates with a regulated health care professional, or unguided, in which the patient is not supported by a regulated health care professional.

METHODS

We conducted a health technology assessment, which included an evaluation of clinical benefit, value for money, and patient preferences and values related to the use of iCBT for the treatment of mild to moderate major depression or anxiety disorders. We performed a systematic review of the clinical and economic literature and conducted a grey literature search. We reported Grading of Recommendations Assessment, Development, and Evaluation (GRADE) ratings if sufficient information was provided. When other quality assessment tools were used by the systematic review authors in the included studies, these were reported. We assessed the risk of bias within the included reviews. We also developed decision-analytic models to compare the costs and benefits of unguided iCBT, guided iCBT, face-to-face CBT, and usual care over 1 year using a sequential approach. We further explored the lifetime and short-term cost-effectiveness of stepped-care models, including iCBT, compared with usual care. We calculated incremental cost-effectiveness ratios (ICERs) from the perspective of the Ontario Ministry of Health and Long-Term Care and estimated the 5-year budget impact of publicly funding iCBT for mild to moderate major depression or anxiety disorders in Ontario. To contextualize the potential value of iCBT as a treatment option for major depression or anxiety disorders, we spoke with people with these conditions.

RESULTS

People who had undergone guided iCBT for mild to moderate major depression (standardized mean difference [SMD] = 0.83, 95% CI 0.59-1.07, GRADE moderate), generalized anxiety disorder (SMD = 0.84, 95% CI 0.45-1.23, GRADE low), panic disorder (small to very large effects, GRADE low), and social phobia (SMD = 0.85, 95% CI 0.66-1.05, GRADE moderate) showed a statistically significant improvement in symptoms compared with people on a waiting list. People who had undergone iCBT for panic disorder (SMD= 1.15, 95% CI: 0.94 to 1.37) and iCBT for social anxiety disorder (SMD=0.91, 95% CI: 0.74-1.07) showed a statistically significant improvement in symptoms compared with people on a waiting list. There was a statistically significant improvement in quality of life for people with generalized anxiety disorder who had undergone iCBT (SMD = 0.38, 95% CI 0.08-0.67) compared with people on a waiting list. The mean differences between people who had undergone iCBT compared with usual care at 3, 5, and 8 months were -4.3, -3.9, and -5.9, respectively. The negative mean difference at each follow-up showed an improvement in symptoms of depression for participants randomized to the iCBT group compared with usual care. People who had undergone guided iCBT showed no statistically significant improvement in symptoms of panic disorder compared with individual or group face-to-face CBT (d = 0.00, 95% CI -0.41 to 0.41, GRADE very low). Similarly, there was no statistically significant difference in symptoms of specific phobia in people who had undergone guided iCBT compared with brief therapist-led exposure (GRADE very low). There was a small statistically significant improvement in symptoms in favour of guided iCBT compared with group face-to-face CBT (d= 0.41, 95% CI 0.03-0.78, GRADE low) for social phobia. There was no statistically significant improvement in quality of life reported for people with panic disorder who had undergone iCBT compared with face-to-face CBT (SMD = -0.07, 95% CI -0.34 to 0.21).Guided iCBT was the optimal strategy in the reference case cost-utility analyses. For adults with mild to moderate major depression, guided iCBT was associated with increases in both quality-adjusted survival (0.04 quality-adjusted life-years [QALYs]) and cost ($1,257), yielding an ICER of $31,575 per QALY gained when compared with usual care. In adults with anxiety disorders, guided iCBT was also associated with increases in both quality-adjusted survival (0.03 QALYs) and cost ($1,395), yielding an ICER of $43,214 per QALY gained when compared with unguided iCBT. In this population, guided iCBT was associated with an ICER of $26,719 per QALY gained when compared with usual care. The probability of cost-effectiveness of guided iCBT for major depression and anxiety disorders, respectively, was 67% and 70% at willingness-to-pay of $100,000 per QALY gained. Guided iCBT delivered within stepped-care models appears to represent good value for money for the treatment of mild to moderate major depression and anxiety disorders.Assuming a 3% increase in access per year (from about 8,000 people in year 1 to about 32,000 people in year 5), the net budget impact of publicly funding guided iCBT for the treatment of mild to moderate major depression would range from about $10 million in year 1 to about $40 million in year 5. The corresponding net budget impact for the treatment of anxiety disorders would range from about $16 million in year 1 (about 13,000 people) to about $65 million in year 5 (about 52,000 people).People with depression or an anxiety disorder with whom we spoke reported that iCBT improves access for those who face challenges with face-to-face therapy because of costs, time, or the severity of their condition. They reported that iCBT provides better control over the pace, time, and location of therapy, as well as greater access to educational material. Some reported barriers to iCBT include the cost of therapy; the need for a computer and internet access, computer literacy, and the ability to understand complex written information. Language and disability barriers also exist. Reported limitations to iCBT include the ridigity of the program, the lack of face-to-face interactions with a therapist, technological difficulties, and the inability of an internet protocol to treat severe depression and some types of anxiety disorder.

CONCLUSIONS

Compared with waiting list, guided iCBT is effective and likely results in symptom improvement in mild to moderate major depression and social phobia. Guided iCBT may improve the symptoms of generalized anxiety disorder and panic disorder compared with waiting list. However, we are uncertain about the effectiveness of iCBT compared with individual or group face-to-face CBT. Guided iCBT represents good value for money and could be offered for the short-term treatment of adults with mild to moderate major depression or anxiety disorders. Most people with mild to moderate depression or anxiety disorders with whom we spoke felt that, despite some perceived limitations, iCBT provides greater control over the time, pace, and location of therapy. It also improves access for people who could not otherwise access therapy because of cost, time, or the nature of their health condition.

A systematic review of network meta-analyses for pharmacological treatment of common mental disorders

QUESTION

Network meta-analyses (NMAs) of treatment efficacy across different pharmacological treatments help inform clinical decision-making, but their methodological quality may vary a lot depending also on the quality of the included primary studies. We therefore conducted a systematic review of NMAs of pharmacological treatment for common mental disorders in order to assess the methodological quality of these NMAs, and to relate study characteristics to the rankings of efficacy and tolerability.

STUDY SELECTION AND ANALYSIS

We searched three databases for NMAs of pharmacological treatment used in major depression, generalised anxiety disorder (GAD), social anxiety disorder (SAD), post-traumatic stress disorder (PTSD), obsessive-compulsive disorder (OCD) and specific phobia.Studies were appraised using the International Society for Pharmacoeconomics and Outcomes Research checklist of good research practices for indirect-treatment-comparison and network-meta-analysis studies.

FINDINGS

Twenty NMAs were eligible for inclusion. The number of randomised controlled trials per NMA ranged from 11 to 234, and included between 801 to more than 26 000 participants. Overall, antidepressants were found to be efficacious and tolerable agents for several disorders based on rankings (45%) or statistical significance (55%). The majority of NMAs in this review adhered to guidelines by including a network diagram (70%), assessing consistency (75%), making use of a random effects model (75%), providing information on the model used to fit the data (75%) and adjusting for covariates (75%).

CONCLUSIONS

The 20 NMAs of depression and anxiety disorders, PTSD and/or OCD included in this review demonstrate some methodological strengths in comparison with the larger body of published NMAs for medical disorders, support current treatment guidelines and help inform clinical decision-making.

Common pitfalls and mistakes in the set-up, analysis and interpretation of results in network meta-analysis: what clinicians should look for in a published article

OBJECTIVE

Several tools have been developed to evaluate the extent to which the findings from a network meta-analysis would be valid; however, applying these tools is a time-consuming task and often requires specific expertise. Clinicians have little time for critical appraisal, and they need to understand the key elements that help them select network meta-analyses that deserve further attention, optimising time and resources. This paper is aimed at providing a practical framework to assess the methodological robustness and reliability of results from network meta-analysis.

METHODS

As a working example, we selected a network meta-analysis about drug treatments for generalised anxiety disorder, which was published in 2011 in the British Medical Journal. The same network meta-analysis was previously used to illustrate the potential of this methodology in a methodological paper published in JAMA.

RESULTS

We reanalysed the 27 studies included in this network following the methods reported in the original article and compared our findings with the published results. We showed how different methodological approaches and the presentation of results can affect conclusions from network meta-analysis. We divided our results into three sections, according to the specific issues that should always be addressed in network meta-analysis: (1) understanding the evidence base, (2) checking the statistical analysis and (3) checking the reporting of findings.

CONCLUSIONS

The validity of the results from network meta-analysis depends on the plausibility of the transitivity assumption. The risk of bias introduced by limitations of individual studies must be considered first and judgement should be used to infer about the plausibility of transitivity. Inconsistency exists when treatment effects from direct and indirect evidence are in disagreement. Unlike transitivity, inconsistency can be always evaluated statistically, and it should be specifically investigated and reported in the published paper. Network meta-analysis allows researchers to list treatments in preferential order; however, in this paper we demonstrated that rankings could be misleading if based on the probability of being the best. Clinicians should always be interested in the effect sizes rather than the naive rankings.

Has the rising placebo response impacted antidepressant clinical trial outcome? Data from the US Food and Drug Administration 1987-2013

More than fifteen years ago, it was noted that the failure rate of antidepressant clinical trials was high, and such negative outcomes were thought to be related to the increasing magnitude of placebo response. However, there is considerable debate regarding this phenomenon and its relationship to outcomes in more recent antidepressant clinical trials. To investigate this, we accessed the US Food and Drug Administration (FDA) reviews for sixteen antidepressants (85 trials, 115 trial arms, 23,109 patients) approved between 1987 and 2013. We calculated the magnitude of placebo and antidepressant responses, antidepressant-placebo differences, as well as the effect sizes and success rates, and compared these measures over time. Exploratory analysis investigated potential changes in trial design and conduct over time. As expected, the magnitude of placebo response has steadily grown in the past 30 years, increasing since 2000 by 6.4% (r=0.46, p<0.001). Contrary to expectations, a similar increase has occurred in the magnitude of antidepressant response (6.0%, r=0.37, p<0.001). Thus, the effect sizes (0.30 vs. 0.29, p=0.42) and the magnitude of antidepressant-placebo differences (10.5% vs. 10.3%, p=0.37) have remained statistically equivalent. Furthermore, the frequency of positive trial arms has gone up in the past 15 years (from 47.8% to 63.8%), but this difference in frequency has not reached statistical significance. Trial design features that were previously associated with a possible lower magnitude of placebo response were not implemented, and their relationship to the magnitude of placebo response could not be replicated. Of the 34 recent trials, two implemented enhanced interview techniques, but both of them were unsuccessful. The results of this study suggest that the relationship between the magnitude of placebo response and the outcome of antidepressant clinical trials is weak at best. These data further indicate that antidepressant-placebo differences are about the same for all of the sixteen antidepressants approved by the FDA in the past thirty years.

Placebo response rates in antidepressant trials: a systematic review of published and unpublished double-blind randomised controlled studies

BACKGROUND

Previous studies have shown that placebo response rates in antidepressant trials have been increasing since the 1970s. However, these studies have been based on outdated or limited datasets and have used inappropriate statistical methods. We did a systematic review of placebo-controlled randomised controlled trials of antidepressants to examine associations between placebo-response rates and study and patient characteristics.

METHODS

In this systematic review, we searched for published and unpublished double-blind randomised placebo-controlled trials of first-generation and second-generation antidepressants for acute treatment of major depression in adults (update: Jan 8, 2016). The log-transformed proportions of placebo response, defined as 50% or greater reduction in depression severity score from baseline, were meta-analytically synthesised for each year. We then looked for a structural break point in the secular changes in these characteristics through the years and examined the influence of the study year and other trial and patient characteristics on the response rates through meta-regression.

FINDINGS

We identified 252 placebo-controlled trials (26 324 patients on placebo) done between 1978 and 2015. There was a structural break in 1991, and since then, the average placebo response rates in antidepressant trials have remained constant in the range between 35% and 40% (relative risk [RR] 1·00, 95% CI 0·97-1·03, p=0·99, for every 5-year increase). The length of the study and the number of study centres were significant factors (RR 1·03, 95% CI 1·01-1·05 for 1 more week in trial length; 1·32, 1·11-1·57 for multicentre vs single-centre trials).

INTERPRETATION

Contrary to the widely held belief, the average placebo response rates in antidepressant trials have been stable for more than 25 years. This new evidence should have an effect on the interpretation of the scientific literature and the future of psychopharmacology, both from a clinical and methodological point of view.

FUNDING

Japan Society for Promotion of Science, Great Britain Sasakawa Foundation.

Does reductio ad absurdum have a place in evidence-based medicine?

In a meta-analysis published in BMC Medicine, we explored whether evidence-based medicine can actually be sure that 'sucrose = sucrose' in the treatment of depression. This paper, based upon a reductio ad absurdum, addressed an epistemological question using a 'scientific' approach, and could be disconcerting as suggested by Cipriani and Geddes' commentary. However, most papers are based upon a mixture of observations and discussions about sense and meaning. Ultimately, there is nothing more than a story, told with words or numbers. Randomised controlled trials provide information about average patients that do not exist. These results ignores an entire segment of therapeutics that plays a crucial role, namely care. This information is usually set out using a 'grammar' that is ambiguous, since statistical tests of hypothesis have raised epistemological questions that are not as yet solved. Moreover, many of these stories remain untold, and unpublished. For these reasons evidence-based medicine is a vehicle for many paradoxes and controversies. Reductio ad absurdum can be useful in precisely this case, to underline how and why the medical literature can sometimes give an impression of absurdity of this sort. Even if the data analysis in our paper was rather rhetorical, we agree that it should comply with the classic standards of reporting and we provide the important extra data that Cipriani and Geddes have requested.