Pharmacogenetic Decision Support Tools: A New Paradigm for Late-Life Depression?

Perspectives on the Clinical Use of Pharmacogenetic Testing in Late-Life Mental Healthcare: A Survey of the American Association of Geriatric Psychiatry Membership

OBJECTIVE

To assess perspectives on pharmacogenetic (PGx) testing among members of the American Association of Geriatric Psychiatry (AAGP).

DESIGN

Cross-sectional survey.

PARTICIPANTS

Members of the AAGP.

MEASUREMENTS

Anonymous web-based survey consisting of 41 items covering experiences, indications, barriers, facilitators and ethical, legal and social implications for PGx testing.

RESULTS

A total of 124 surveys were completed (response rate = 13%). Most respondents (60%) had used PGx testing but an equal proportion (58%) was uncertain about the clinical usefulness of PGx testing in late-life mental health. Despite self-reported confidence in the ability to order and interpret PGx testing, 60% of respondents felt there was not enough clinical evidence for them to use PGx testing in their practice. This was compounded by uncertainties related to their ethical obligation and legal liability when interpreting and using (or not using) PGx testing results. Respondents strongly affirmed that clinical and legal guidelines for PGx testing in older adults are needed and would be helpful.

CONCLUSION

The findings suggest additional PGx research and physician education in late-life mental healthcare settings is required to reconcile uncertainties related to the clinical efficacy and ethico-legal aspects of PGx testing as well as address current knowledge barriers to testing uptake. These efforts would be further facilitated by the development of clinical practice guidelines to ensure equitable access to testing and standardized implementation of PGx-informed prescribing in older adults.

Effect of Pharmacogenetic-Based Decision Support Tools in Improving Depression Outcomes: A Systematic Review

OBJECTIVE

Evidence supporting the utility of pharmacogenetic (PGX) tests in depression is scarce. The main objectives of this study were to summarize, update, and assess the quality of the available evidence regarding PGX testing in depression as well as estimating the impact of using PGX testing tools in depression outcomes in the Middle East/North Africa (MENA) region.

METHODOLOGY

Scientific databases were systematically searched from inception to June 30, 2020 for systematic reviews and randomized controlled trials (RCTs) assessing the clinical utility of PGX tests in the treatment of depression. Meta-analyses only and RCTs that were included in eligible systematic reviews were excluded. The quality of the eligible studies was assessed using the Crowe Critical Appraisal Tool (CCAT).

RESULTS

Six systematic reviews and three RCTs met the inclusion criteria and were included in this study. The results of the systematic reviews provided weak evidence on the efficacy of PGX testing, especially in patients with moderate-severe depression at 8 weeks. In addition, there was a lack of evidence regarding safety outcomes. Newer RCTs with better quality showed clinical promise regarding efficacy outcomes, especially in patients with gene-drug interactions. No evidence was found regarding PGX testing impact in the MENA region.

CONCLUSION

This systematic review is an update and summary of the available literature on the clinical utility of PGX testing in depression. The findings of this study demonstrate that PGX testing prior to treatment initiation or during the course of therapy may improve efficacy outcomes. Further studies are warranted to assess the impact of PGX testing on safety outcomes.

An update on antidepressant pharmacotherapy in late-life depression

Introduction: Clinically important depressive symptoms that occur in adults over age 60 are often termed late-life depression (LLD). LLD poses challenges for treating clinicians in both detection and treatment. Antidepressants are the most common first-line treatment approach. Older adults are at an increased risk of adverse effects because of polypharmacy.Areas covered: This article summarizes the challenges and approaches when using pharmacotherapy in LLD with a focus on newer data that have become available during the last five years. While no new antidepressants have become available during this period, a review of the literature summarizes advances in the knowledge of the adverse effects associated with various antidepressants and on the potential contribution of pharmacogenetic tools when prescribing antidepressants to older patients.Expert opinion: During the past 5 years, most of the literature relevant to the pharmacotherapy of MDD in older patients has focused on adverse effects. In particular, the effects of antidepressants on cognition and bone are emerging as important areas for clinical attention and further investigation. There is also an emerging literature on the potential role of pharmacogenetic testing in patients with MDD, though recommendations for use in older adults await larger studies that demonstrate its efficacy and cost-effectiveness.

Rates of genetic testing in patients prescribed drugs with pharmacogenomic information in FDA-approved labeling

This study examined rates of genetic testing in two cohorts of publicly insured individuals who have newly prescribed medication with FDA pharmacogenomic labeling guidance. Genetic testing was rare (4.4% and 10.5% in Medicaid and Medicare cohorts, respectively) despite the fact that all participants selected were taking medications that contained pharmacogenomic labeling information. When testing was conducted it was typically done before the initial use of a target medication. Factors that emerged as predictors of the likelihood of undergoing genetic testing included White ethnicity (vs. Black), female gender, and age. Cost analyses indicated higher expenditures in groups receiving genetic testing vs. matched comparators with no genetic testing, as well as disparities between proactively and reactively tested groups (albeit in opposite directions across cohorts). Results are discussed in terms of the possible reasons for the low base rate of testing, mechanisms of increased cost, and barriers to dissemination and implementation of these tests.

Combinatorial Pharmacogenomic Testing Improves Outcomes for Older Adults With Depression

(Reprinted with permission from Am J Geriatr Psychiatry 2020; 28:933-945).

Combinatorial Pharmacogenomic Testing Improves Outcomes for Older Adults With Depression

OBJECTIVE

Evaluate the clinical utility of combinatorial pharmacogenomic testing for informing medication selection among older adults who have experienced antidepressant medication failure for major depressive disorder (MDD).

DESIGN

Post hoc analysis of data from a blinded, randomized controlled trial comparing two active treatment arms.

SETTING

Psychiatry specialty and primary care clinics across 60 U.S. community and academic sites.

PARTICIPANTS

Adults age 65 years or older at baseline (n = 206), diagnosed with MDD and inadequate response to at least one medication on the combinatorial pharmacogenomic test report during the current depressive episode.

INTERVENTION

Combinatorial pharmacogenomic testing to inform medication selection (guided-care), compared with treatment as usual (TAU).

OUTCOMES

Mean percent symptom improvement, response rate, and remission rateat week 8, measured using the 17-item Hamilton Depression Rating Scale; medication switching; and comorbidity moderator analysis.

RESULTS

At week 8, symptom improvement was not significantly different for guided-care than for TAU (∆ = 8.1%, t = 1.64, df = 187; p = 0.102); however, guided-care showed significantly improved response (∆ = 13.6%, t = 2.16, df = 187; p = 0.032) and remission (∆ = 12.7%, t = 2.49, df = 189; p = 0.014) relative to TAU. By week 8, more than twice as many patients in guided-care than in TAU were on medications predicted to have no gene-drug interactions (χ² = 19.3, df = 2; p <0.001). Outcomes in the guided-care arm showed consistent improvement through the end of the open-design 24-week trial, indicating durability of the effect. Differences in outcomes between arms were not significantly impacted by comorbidities.

CONCLUSIONS

Combinatorial pharmacogenomic test-informed medication selection improved outcomes over TAU among older adults with depression.

Brain health INnovation Diplomacy: a model binding diverse disciplines to manage the promise and perils of technological innovation

BACKGROUND

Brain health diplomacy aims to influence the global policy environment for brain health (i.e. dementia, depression, and other mind/brain disorders) and bridges the disciplines of global brain health, international affairs, management, law, and economics. Determinants of brain health include educational attainment, diet, access to health care, physical activity, social support, and environmental exposures, as well as chronic brain disorders and treatment. Global challenges associated with these determinants include large-scale conflicts and consequent mass migration, chemical contaminants, air quality, socioeconomic status, climate change, and global population aging. Given the rapidly advancing technological innovations impacting brain health, it is paramount to optimize the benefits and mitigate the drawbacks of such technologies.

OBJECTIVE

We propose a working model of Brain health INnovation Diplomacy (BIND).

METHODS

We prepared a selective review using literature searches of studies pertaining to brain health technological innovation and diplomacy.

RESULTS

BIND aims to improve global brain health outcomes by leveraging technological innovation, entrepreneurship, and innovation diplomacy. It acknowledges the key role that technology, entrepreneurship, and digitization play and will increasingly play in the future of brain health for individuals and societies alike. It strengthens the positive role of novel solutions, recognizes and works to manage both real and potential risks of digital platforms. It is recognition of the political, ethical, cultural, and economic influences that brain health technological innovation and entrepreneurship can have.

CONCLUSIONS

By creating a framework for BIND, we can use this to ensure a systematic model for the use of technology to optimize brain health.

Pharmacogenetic Implications for Antidepressant Pharmacotherapy in Late-Life Depression: A Systematic Review of the Literature for Response, Pharmacokinetics and Adverse Drug Reactions

Affecting up to 15% of older adults, late-life depression (LLD) is characterized by the occurrence of depressive symptoms after the age of 50-65 years and maybe pathophysiologically distinct from depression in younger adults. Therefore, LLD is challenging to treat, and predictive genetic testing might be essential to improve treatment in this vulnerable population. The current review aims to provide a summary of the literature exploring genetic associations with antidepressant treatment outcomes in late-life. We conducted a systematic search of three integrated electronic databases. We identified 29 articles investigating genetic associations with antidepressant treatment outcomes, pharmacokinetic parameters, and adverse drug reactions in older adults. Given the small number of investigations conducted in older adults, it is difficult to conclude the presence or absence of genetic associations with the outcomes of interest. In sum, the most substantial amount of evidence exists for the CYP2D6 metabolizer status, SLC6A4 5-HTTLPR, and BDNF rs6265. These findings are consistent in the literature when not restricting to older adults, suggesting that similar treatment recommendations may be provided for older adults regarding genetic variation, such as those outlined for CYP2D6 by the Clinical Pharmacogenetics Implementation Consortium. Nonetheless, further studies are required in well-characterized samples, including genome-wide data, to validate if similar treatment adjustments are appropriate in older adults, given that there appear to be significant effects of genetic variation on antidepressant treatment factors.

Getting to precision psychopharmacology: Combining clinical and genetic information to predict fat gain from aripiprazole

INTRODUCTION

All atypical antipsychotics are associated with some degree of weight gain. We applied a novel statistical approach to identify moderators of aripiprazole-induced fat gain using clinical and genetic data from a randomized clinical trial (RCT) of treatment resistant depression in older adults.

MATERIALS AND METHODS

Adults aged ≥60 years with non-response to a prospective trial of venlafaxine were randomized to 12 weeks of aripiprazole augmentation (n = 91) or placebo (n = 90). Dual energy x-ray absorptiometry (DEXA) measured adiposity at baseline and 12 weeks. Independent moderators of total body fat gain were used to generate two combined multiple moderators, one including clinical data alone and one including both clinical and genetic data to characterize individuals who gained fat during aripiprazole augmentation.

RESULTS

The value of the combined genetic + clinical multiple moderator (M_cg) was 0.57 [95% CI 0.46, 0.68] (effect size: 0.57), compared to the combined clinical moderator (M_c) value of 0.49 [0.34, 0.63] (effect size: 0.49). Individuals who gained adiposity in this study were more likely to be female and younger in age, have lower weight, fasting glucose and lipids at baseline and positive for the HTR2C polymorphism.

DISCUSSION

These results demonstrate a combined multiple moderator approach, including both clinical and genetic moderators, can be applied to existing clinical trial data to understand adverse treatment effects. This method allowed for more specific characterization of individuals at risk for the outcome of interest. Further work is needed to identify additional genetic moderators and to validate the approach.

Pharmacogenetics of Antidepressants: from Genetic Findings to Predictive Strategies

The constantly growing contribution of depressive disorders to the global disease statistics calls for a growth of treatment effectiveness and optimization. Antidepressants are the most frequently prescribed medicines for depressive disorders. However, development of a standardized pharmacotherapeutic approach is burdened by the genomic heterogeneity, lack of reliable predictive biomarkers and variability of the medicines metabolism aggravated by multiple side effects of antidepressants. According to modern assessments up to 20 % of the genes expressed in our brain are involved in the pathogenesis of depression. Large-scale genetic and genomic research has found a number of potentially prognostic genes. It has also been proven that the effectiveness and tolerability of antidepressants directly depend on the variable activity of the enzymes that metabolize medicines. Almost all modern antidepressants are metabolized by the cytochrome P450 family enzymes. The most promising direction of research today is the GWAS (Genome-Wide Association Study) method that is aimed to link genomic variations with phenotypical manifestations. In this type of research genomes of depressive patients with different phenotypes are compared to the genomes of the control group containing same age, sex and other parameters healthy people. Notably, regardless of the large cohorts of patients analyzed, none of the GWA studies conducted so far can reliably reproduce the results of other analogous studies. The explicit heterogeneity of the genes associated with the depression pathogenesis and their pleiotropic effects are strongly influenced by environmental factors. This may explain the difficulty of obtaining clear and reproducible results. However, despite any negative circumstances, the active multidirectional research conducted today, raises the hope of clinicians and their patients to get a whole number of schedules how to achieve remission faster and with guaranteed results

Does obtaining CYP2D6 and CYP2C19 pharmacogenetic testing predict antidepressant response or adverse drug reactions?

Treatment non-response and adverse reactions are common in patients receiving antidepressants. Personalizing psychiatric treatment based on pharmacogenetic testing has been proposed to help clinicians guide antidepressant selection and dosing. This systematic literature review assesses the two most robustly studied drug-metabolizing enzymes, CYP2D6 and CYP2C19, and examines whether obtaining CYP2D6 and CYP2C19 testing can be used to predict antidepressant response or adverse drug reactions in order to improve clinical outcomes. In general, literature reviews published prior to 2013 indicated that results have been inconsistent linking CYP2D6 and CYP2C19 to antidepressant treatment outcomes, suggesting that more evidence is required to support the clinical implementation of genotyping to predict outcomes. We thus performed an extensive and systematic literature review, focusing on studies published from 2013 through 2018. Sixteen studies were found to be relevant. The results yielded inconsistent findings, suggesting that CYP2D6 and CYP2C19 testing may predict response in certain individuals, but it remains unclear if this will translate to improved clinical outcomes. Further research is required to determine when pharmacogenetic testing should be utilized and in which populations it is indicated. Randomized, controlled, prospective trials with adequate sample sizes would best clarify whether genotype-guided antidepressant selection will ultimately improve clinical outcomes.

Pharmacogenetic guidelines and decision support tools for depression treatment: application to late-life

Late-life depression (LLD) is a major depressive disorder that affects someone after the age of 60 years. LLD is frequently associated with inadequate response and remission from antidepressants, in addition to polypharmacy. Pharmacogenetics offers a promising approach to improve clinical outcomes in LLD via new discoveries determining the genetic basis of response rates and side effects, as well as the development of tailored pharmacogenetic-based decision support tools. This invited review evaluates the LLD pharmacogenetic evidence base and the extent to which this was incorporated into existing commercial decision support tools and clinical pharmacogenetic guidelines.

Predictors of Response and Remission to Antidepressants in Geriatric Depression: A Systematic Review

BACKGROUND

Geriatric depression is a heterogeneous disorder that increases morbidity and mortality in a population that is already vulnerable. Predicting response and remission to antidepressants could help clinicians to optimize the management of antidepressants and reduce the consequences of depression.

METHOD

The aim of this article is to present results of a systematic review of the literature on predictive factors related to antidepressant response and remission in older adults with depression.

MAIN FINDINGS

We identified sociodemographic, clinical, neuropsychological, neuroimaging, and genetic factors that could be potential predictors of outcomes. Inconsistent findings and methodological differences among studies, however, limit the generalizability and application of these predictors in clinical practice. The results of our review confirm that geriatric depression includes many subgroups of patients with particular endophenotypes that may influence the course of depression.

CONCLUSION

Further studies are needed to characterize depression subgroups in order to better understand the pathophysiology of late life depression and to find specific predictors for each group of patients.

Fortune and hindsight: gene patents' muted effect on medical practice

INTRODUCTION

Physicians have long worried about gene patents' potential to restrict their medical practices. Fortune and hindsight have proven these worries exaggerated both in the UK and elsewhere. Neither current nor future medical practices appear to be impinged by gene patents, although they may be subject to future intellectual property disputes.

SOURCES OF DATA

Qualitative and quantitative (survey) studies of gene patents' effects on medical practice; recent developments in patent law.

AREAS OF AGREEMENT

Traditional gene patents do not appear to have restricted medical practice in the UK, although their effect elsewhere has been more nuanced.

AREAS OF CONTROVERSY

Whether patents will restrict the spread of newer medical technologies is unresolved.

AREAS TIMELY FOR DEVELOPING RESEARCH

Continuing survey data on practitioners' views concerning patents' role in the distribution of newer technologies would be beneficial.