Principle standards and problems regarding proof of efficacy in clinical psychopharmacology

A novel human laboratory model for screening medications for alcohol use disorder

Background

Alcohol use disorder (AUD) is a highly prevalent, chronic relapsing disorder with a high disease burden in the USA. Pharmacotherapy is a promising treatment method for AUD; however, the few FDA-approved medications are only modestly effective. Medications development for AUD is a high priority research area, but the cumbersome drug development process hinders many potential compounds from reaching approval. One area with major opportunities for improvement is the process of screening novel compounds for initial efficacy, also known as early phase 2 trials. Early phase 2 trials incorporate human laboratory paradigms to assess relevant clinical constructs, such as craving and subjective responses to alcohol. However, these controlled paradigms often lack the ecological validity of clinical trials. Therefore, early phase 2 trials can be more efficient and clinically meaningful if they combine the internal validity of experimental laboratory testing with the external validity of clinical trials. To that end, the current study aims to develop and validate a novel early efficacy paradigm, informed by smoking cessation literature, to screen novel medications for AUD. As an established AUD medication, naltrexone will serve as an active control to test both the practice quit attempt model and the efficacy of a promising AUD pharmacotherapy, varenicline.

Methods

Individuals with current AUD reporting intrinsic motivation to change their drinking will complete a week-long “practice quit attempt” while on study medication. Participants are randomized and blinded to either naltrexone, varenicline, or placebo. During the practice quit attempt, participants will complete daily visits over the phone and fill out online questionnaires regarding their drinking, alcohol craving, and mood. Additionally, participants will undergo two alcohol cue-reactivity sessions.

Discussion

The successful completion of this study will advance medications development by proposing and validating a novel early efficacy model for screening AUD pharmacotherapies, which in turn can serve as an efficient strategy for making go/no-go decisions as to whether to proceed with clinical trials.

Trial registration

ClinicalTrials.gov NCT04249882. Registered on 31 January 2020.

Position statement of the European Psychiatric Association (EPA) on the value of antidepressants in the treatment of unipolar depression

This position statement will address in an evidence-based approach some of the important issues and controversies of current drug treatment of depression such as the efficacy of antidepressants, their effect on suicidality and their place in a complex psychiatric treatment strategy including psychotherapy. The efficacy of antidepressants is clinically relevant. The highest effect size was demonstrated for severe depression. Based on responder rates and based on double-blind placebo-controlled studies, the number needed to treat (NNT) is 5–7 for acute treatment and four for maintenance treatment. Monotherapy with one drug is often not sufficient and has to be followed by other antidepressants or by comedication/augmentation therapy approaches. Generally, antidepressants reduce suicidality, but under special conditions like young age or personality disorder, they can also increase suicidality. However, under the conditions of good clinical practice, the risk–benefit relationship of treatment with antidepressants can be judged as favourable also in this respect. The capacity of psychiatrists to individualise and optimise treatment decisions in terms of ‘the right drug/treatment for the right patient’ is still restricted since currently there are no sufficient powerful clinical or biological predictors which could help to achieve this goal. There is hope that in future pharmacogenetics will contribute significantly to a personalised treatment. With regard to plasma concentration, therapeutic drug monitoring (TDM) is a useful tool to optimize plasma levels therapeutic outcome. The ideal that all steps of clinical decision-making can be based on the strict rules of evidence-based medicine is far away from reality. Clinical experience so far still has a great impact.

The identification of biomarkers predicting acute and maintenance lithium treatment response in bipolar disorder: A plea for further research attention

The prediction of acute and maintenance lithium treatment response carries major clinical and neurobiological implications, warranting systematic review. A Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) compliant review searched major electronic databases from inception until December 2017 for studies documenting a clinical diagnosis of bipolar disorder (BD) made according to the mainstream diagnostic manuals and confirmed by a structured interview. Eligible studies allowed a quantitative comparison of endpoint vs baseline mean values of a given biomarker, regardless of the mood phase of patients with BD, and the disorder was assessed for severity using validated rating tool(s). Owing to the purposely applied stringent selection criteria, 16 acute and 12 maintenance studies could be included. The anticipated publication bias limited the chances of reportable generalizable findings, hindering a side-by-side comparison of different records across varying biomarkers and subsequent meta-analyses. The PRISMA approach was nonetheless preferred; it aimed at enhancing the homogeneity of the included results and minimizing the chances of "apples and oranges" with respect to the present research theme. The present critical review confirms the need for future research to specifically assess either pretreatment and/or posttreatment putative biomarkers of patients with BD and treated with lithium.

Burning issues in the meta-analysis of pharmaceutical trials for depression

During the last decade a number of meta-analytic studies have been published and they triggered a debate on the true clinical usefulness of antidepressants. The current article comments on problems within the randomized controlled trials design, the study samples, the psychometric scales, the methods of meta-analysis, the interpretation of the results, and the reporting of conflicts of interest. Although the meta-analyses published so far agree that medication works in severe depression, they question its efficacy in mild cases. However, several methodological issues should be clarified before conclusions are definite. Different methods give different results and similar results seem to entertain a variety of interpretations. In the future it is important to address all of these problems, and to improve methodology on the basis of clinically informed choices. Otherwise, meta-analysis risks alienation from clinical reality and thus risks becoming the 21(st) century psychoanalysis.

Head to head comparisons as an alternative to placebo-controlled trials

Head to head trials have been proposed as an alternative to the ethical and methodological concerns related to placebo-controlled trials. While those studies may be particularly informative from the clinical and cost-effectiveness point-of-view, avoiding placebo poses several regulatory concerns: for superiority designs, the choice of the trial population, outcomes, dose and escalation of the comparator, as well as the comparator itself may be an issue; for non-inferiority studies, issues related to uncertain assay sensitivity and exposure of large samples to potentially ineffective or unsafe drugs make them inappropriate, in the absence of a previous positive superiority trial, for regulatory purposes. The inclusion of active comparators in regulatory trials should not be seen as an alternative, but as a useful complement to the information that can be obtained from placebo-controlled studies.

Standardized diagnostic interviews, criteria, and algorithms for mental disorders: garbage in, garbage out

There is a general consensus that diagnoses for mental disorders should be based on criteria and algorithms as given in ICD or DSM. Standardized clinical interviews are recommended as diagnostic methods. In ICD and DSM, much emphasis is put on algorithms, while the underlying criteria get much less attention. The question is how valid are the criteria that are collected by structured diagnostic interviews. 209 patients from a cardiology inpatient unit were interviewed with the Mini International Neuropsychiatric Interview (MINI). 32 (15.3%) were diagnosed as suffering from a major depressive episode or dysthymia. Additionally, a thorough clinical examination was done by a psychiatric expert in 15 patients. The standardized diagnosis of present major depression was reaffirmed in one. In total, four patients were suffering from some kind of depressive disorder presently or life time. Two patients were suffering from anxiety disorders, two from adjustment disorders, and four from different types of organic brain disorders. Most important, there are 3 out of 15 who are not mentally ill. Our observations show that standardized diagnostic interviews cannot be used to make specific differential diagnoses, but rather catch unspecific syndromes. This is partly due to the fact that the wording, definition, and understanding of the underlying criteria is rather vague. This is an even greater problem if there is any somatic comorbidity. In the revision of ICD and DSM, a glossary of psychopathological terms and guidelines for the training of clinicians should be included.

Ethics of clinical research with mentally ill persons

This article describes ethical, legal and professional components of the two core requirements of clinical research: informed consent and risk-benefit relationships. It deals particularly with the ethically relevant reasons, criteria, procedures and validity of (1) the informed consent process, (2) the relationship between benefits and risks, and as a requirement of its assessment: (3) standards and (quasi quantitative) criteria of benefits and risks and/or burdens of a research intervention. These requirements will be discussed with specific reference to research interventions in mentally ill patients, and particularly in those who are incompetent to consent. (4) The analysis concludes by demanding a strong adherence to the ethical rules of clinical research in order to protect participants and preserve the trust of both the patients and the public and (5) yields in a set of recommendations.

How close is evidence to truth in evidence-based treatment of mental disorders?

Given the importance of the term 'evidence' in evidence-based medicine (EBM), the meaning of this term is evaluated, going back to the philosophical tradition and current meaning of the terms 'evidence' and 'truth'. Based on this, current problems in the definition of evidence and in the grading of evidence in EBM are described, taking examples from the field of psychiatry and especially pharmacopsychiatry. These problems underline that the use of the term evidence in EBM is inconsistent and inconclusive. This should be fairly stated in all EBM-related publications, especially in EBM-based guidelines, to avoid severe misunderstandings in and outside the field of psychiatry. Although EBM might have increased empirically driven rational decision-making in psychiatry/medicine, the current limitations should be carefully considered.

Antidepressant drugs and the response in the placebo group: the real problem lies in our understanding of the issue

In a recent paper, Horder and colleagues (Horder et al., 2010, J Psychopharmacol 25: 1277-1288) have suggested that the mainproblem in the Kirsch analysis is methodological. We argue that the results are similar irrespective of the method used. In our opinion the data suggest that placebo and drug effects are non-additive: antidepressants act independently of depression severity, while the placebo effect is present only in milder cases. While the response in the placebo group is due to unstable 'noise' and 'artefacts', the medication effect is reliable, valid and stable.

Critical trial-related criteria in acute schizophrenia studies

The Trial Criteria in Schizophrenia Working Group was convened in November 2007 to define consensus criteria for clinical trials in patients suffering from acute schizophrenia with special focus on placebo-controlled trials and withdrawal conditions. Clinical trials involving patients give rise to ethical and medico-legal dilemmas. Essential research of new drugs may potentially expose patients to ineffective treatment regimens or placebo. The complexity of the problem increases when dealing with mentally ill patients. The Working Group's criteria are thought to cover different aspects important in conducting clinical trials namely to ensure the patient's safety, to present criteria that would allow the ethics committees to agree to the proposed criteria and to enable the possibility to reasonably conduct and ensure comparable quality of clinical studies in acutely ill patients with schizophrenia. To furthermore counteract current inconsistencies, these criteria should be evaluated using standardized rating scales applying established cut-off criteria. The developed trial criteria cover inclusion and exclusion criteria as well as withdrawal criteria due to non-response or worsening of symptoms.

General and comparative efficacy and effectiveness of antidepressants in the acute treatment of depressive disorders: a report by the WPA section of pharmacopsychiatry

Current gold standard approaches to the treatment of depression include pharmacotherapeutic and psychotherapeutic interventions with social support. Due to current controversies concerning the efficacy of antidepressants in randomized controlled trials, the generalizability of study findings to wider clinical practice and the increasing importance of socioeconomic considerations, it seems timely to address the uncertainty of concerned patients and relatives, and their treating psychiatrists and general practitioners. We therefore discuss both the efficacy and clinical effectiveness of antidepressants in the treatment of depressive disorders. We explain and clarify useful measures for assessing clinically meaningful antidepressant treatment effects and the types of studies that are useful for addressing uncertainties. This includes considerations of methodological issues in randomized controlled studies, meta-analyses, and effectiveness studies. Furthermore, we summarize the differential efficacy and effectiveness of antidepressants with distinct pharmacodynamic properties, and differences between studies using antidepressants and/or psychotherapy. We also address the differential effectiveness of antidepressant drugs with differing modes of action and in varying subtypes of depressive disorder. After highlighting the clinical usefulness of treatment algorithms and the divergent biological, psychological, and clinical efforts to predict the effectiveness of antidepressant treatments, we conclude that the spectrum of different antidepressant treatments has broadened over the last few decades. The efficacy and clinical effectiveness of antidepressants is statistically significant, clinically relevant, and proven repeatedly. Further optimization of treatment can be helped by clearly structured treatment algorithms and the implementation of psychotherapeutic interventions. Modern individualized antidepressant treatment is in most cases a well-tolerated and efficacious approach to minimize the negative impact of otherwise potentially devastating and life-threatening outcomes in depressive disorders.

Effectiveness studies: advantages and disadvantages

In recent years, so-called “effectiveness studies,” also called “real-world studies” or “pragmatic trials, ” have gained increasing importance in the context of evidencebased medicine. These studies follow less restrictive methodological standards than phase III studies in terms of patient selection, comedication, and other design issues, and their results should therefore be better generalizable than those of phase III trials. Effectiveness studies, like other types of phase IV studies, can therefore contribute to knowledge about medications and supply relevant information in addition to that gained from phase III trials. However, the less restrictive design and inherent methodological problems of phase IV studies have to be carefully considered. For example, the greater variance caused by the different kinds of confounders as well as problematic design issues, such as insensitive primary outcome criteria, unblinded treatment conditions, inclusion of chronic refractory patients, etc, can lead to wrong conclusions. Due to these methodological problems, effectiveness studies are on a principally lower level of evidence, adding only a complementary view to the results of phase III trials without falsifying their results.

Efficacy of antidepressants: a re-analysis and re-interpretation of the Kirsch data

Recently there has been much debate on the true usefulness of antidepressant therapy especially after the publication of a meta-analysis by Kirsch et al. (PLoS Medicine 2008, 5, e45). The aim of the current paper was to recalculate and re-interpret the data of that study. Effect-size and mean-score changes were calculated for each agent separately as well as pooled effect sizes and mean changes on the basis of the data reported by Kirsch et al. The weighted mean improvement was (depending on the method of calculation) 10.04 or 10.16 points on the Hamilton Depression Rating Scale (HAMD) in the drug groups, instead of 9.60, and thus the correct drug-placebo difference is 2.18 or 2.68 instead of 1.80. Kirsch et al. failed to report that that the change in HAMD score was 3.15 or 3.47 points for venlafaxine and 3.12 or 3.22 for paroxetine, which are above the NICE threshold. Still the figures for fluoxetine and nefazodone are low. Thus it seems that the Kirsch et al.'s meta-analysis suffered from important flaws in the calculations; reporting of the results was selective and conclusions unjustified and overemphasized. Overall the results suggest that although a large percentage of the placebo response is due to expectancy this is not true for the active drug and effects are not additive. The drug effect is always present and is unrelated to depression severity, while this is not true for placebo.

Meta-analysis: fact or fiction? How to interpret meta-analyses

OBJECTIVES

Widespread use of increasingly complex statistical methods makes it ever more challenging to adequately assess the results reported and conclusions drawn in meta-analytic research. This paper aims to identify potential fallacies by in-depth examination of recent publications on mood disorders.

METHODS

Three meta-analyses were selected based on availability of data and representativeness of methods employed. By means of detailed re-analysis, several widespread methodological problems were identified, and the example data were used to illustrate and discuss them.

RESULTS

General points addressed include clear formulation of the research question, choice of effect size measures, and general choice of model. Data quality problems like missing data and publication bias are discussed along with methods to deal with them. Furthermore, aspects of meta-analytic modelling like the use of fixed or random effects, data aggregation, as well as the use of subgroups are explained, and issues of excessive complexity and data dredging pointed out. Finally, the benefit of diagnostic tools like confidence bands and the importance of transparency regarding data and methodology for the interpretation of meta-analytic results are highlighted.

CONCLUSIONS

Practically relevant quality criteria for readers to bear in mind when dealing with meta-analytic publications are summarized in a ten point checklist.