Physicians' opinions following pharmacogenetic testing for psychotropic medication

Providers' Use of Pharmacogenetic Testing to Inform Antidepressant Prescribing: Results of Qualitative Interviews

OBJECTIVE

Pharmacogenetic testing (PGx) for patients experiencing depression has been associated with modest improvements in symptoms. However, little is known about providers' use of PGx, including how and for whom providers use the test results in clinical decision making. In this article, results from qualitative interviews on the experience of providers participating in a pragmatic trial of PGx are described; implications of the providers' experiences are highlighted to inform future implementation of PGx.

METHODS

Interviews were conducted with providers participating in the trial (N=61) who treated veterans who had depression. Questions were informed by the Consolidated Framework for Implementation Research. A rapid analytic approach was used.

RESULTS

Two main themes were identified: perceptions regarding which patients would likely benefit from PGx and approaches to using the test results in prescribing. Providers generally expressed positive experiences with using PGx results. However, the providers varied in application of the test results to clinical decision making regarding medications, were uncertain about how much to rely on the results, and differed in perceptions about which patients would benefit from PGx.

CONCLUSIONS

To support future implementation, policies and procedures are needed, as well as mechanisms to support ongoing provider education on PGx.

Pharmacogenomic Testing for Major Depression: A Qualitative Study of the Perceptions of People with Lived Experience and Professional Stakeholders

OBJECTIVES

With increasing evidence for the clinical utility of pharmacogenomic (PGx) testing for depression, there is a growing need to consider issues related to the clinical implementation of this testing. The perspectives of key stakeholders (both people with lived experience [PWLE] and providers) are critical, but not frequently explored. The purpose of this study was to understand how PWLE and healthcare providers/policy experts (P/HCPs) perceive PGx testing for depression, to inform the consideration of clinical implementation within the healthcare system in British Columbia (BC), Canada.

METHODS

We recruited two cohorts of participants to complete individual 1-h, semi-structured interviews: (a) PWLE, recruited from patient and research engagement networks and organizations and (b) P/HCPs, recruited via targeted invitation. Interviews were audiotaped, transcribed verbatim, de-identified, and analysed using interpretive description.

RESULTS

Seventeen interviews were completed with PWLE (7 with experience of PGx testing for depression; 10 without); 15 interviews were completed with P/HCPs (family physicians, psychiatrists, nurses, pharmacists, genetic counsellors, medical geneticists, lab technologists, program directors, and insurers). Visual models of PWLE's and P/HCP's perceptions of and attitudes towards PGx testing were developed separately, but both were heavily influenced by participants' prior professional and/or personal experiences with depression and/or PGx testing. Both groups expressed a need for evidence and numerous considerations for the implementation of PGx testing in BC, including the requirement for conclusive economic analyses, patient and provider education, technological and clinical support, local testing facilities, and measures to ensure equitable access to testing.

CONCLUSIONS

While hopeful about the potential for therapeutic benefit from PGx testing, PWLE and P/HCPs see the need for robust evidence of utility, and BC-wide infrastructure and policies to ensure equitable and effective access to PGx testing. Further research into the accessibility, effectiveness, and cost-effectiveness of various implementation strategies is needed to inform PGx testing use in BC.

Real-World Implementation of Precision Psychiatry: A Systematic Review of Barriers and Facilitators

Background: Despite significant research progress surrounding precision medicine in psychiatry, there has been little tangible impact upon real-world clinical care. Objective: To identify barriers and facilitators affecting the real-world implementation of precision psychiatry. Method: A PRISMA-compliant systematic literature search of primary research studies, conducted in the Web of Science, Cochrane Central Register of Controlled Trials, PsycINFO and OpenGrey databases. We included a qualitative data synthesis structured according to the ‘Consolidated Framework for Implementation Research’ (CFIR) key constructs. Results: Of 93,886 records screened, 28 studies were suitable for inclusion. The included studies reported 38 barriers and facilitators attributed to the CFIR constructs. Commonly reported barriers included: potential psychological harm to the service user (n = 11), cost and time investments (n = 9), potential economic and occupational harm to the service user (n = 8), poor accuracy and utility of the model (n = 8), and poor perceived competence in precision medicine amongst staff (n = 7). The most highly reported facilitator was the availability of adequate competence and skills training for staff (n = 7). Conclusions: Psychiatry faces widespread challenges in the implementation of precision medicine methods. Innovative solutions are required at the level of the individual and the wider system to fulfil the translational gap and impact real-world care.

Gene-drug pairings for antidepressants and antipsychotics: level of evidence and clinical application

Substantial inter-individual discrepancies exist in both therapeutic effectiveness and adverse effects of antidepressant and antipsychotic medications, which can, in part, be explained by genetic variation. Here, we searched the Pharmacogenomics Knowledge Base for gene-antidepressant and gene-antipsychotic pairs with the highest level of evidence. We then extracted and compared the associated prescribing recommendations for these pairs developed by the Clinical Pharmacogenomics Implementation Consortium, the Dutch Pharmacogenetics Working Group or approved product labels in the US, Canada, Europe, and Asia. Finally, we highlight key economical, educational, regulatory, and ethical issues that, if not appropriately considered, can hinder the implementation of these recommendations in clinical practice. Our review indicates that evidence-based guidelines are available to assist with the implementation of pharmacogenetic-guided antidepressant and antipsychotic prescribing, although the maximum impact of these guidelines on patient care will not be realized until key barriers are minimized or eliminated.

A systematic review of pharmacogenetic testing in primary care: Attitudes of patients, general practitioners, and pharmacists

BACKGROUND

Pharmacogenetic testing enhances patient safety by improving medical treatment and reducing side effects. It has shown potential in both primary and secondary care. However, implementation in healthcare, particularly in primary care, is slow.

OBJECTIVE

The objective was to review articles published on the attitudes towards, and knowledge on pharmacogenetic testing in primary care, among general practitioners, pharmacists, and patients.

METHODS

The review was performed according to the PRISMA checklist. A systemized literature search was followed by a 2-step screening process. Apart from the content of articles being within the scope of the review, inclusion criteria included: articles in English; primary research articles; qualitative, quantitative, or mixed methods. Content analysis was conducted as a qualitative meta-synthesis. The methodological rigor of included articles was assessed.

RESULTS

Fifteen studies were included. The analysis resulted in the following main themes: i) benefits of pharmacogenetic testing, ii) barriers to pharmacogenetic testing, iii) pharmacists' role in pharmacogenetic counselling, and iv) pharmacists' knowledge on pharmacogenetics. Methodological rigor was generally medium/high.

CONCLUSIONS

More studies are needed in this area, and there is a need for more education on pharmacogenetic testing for healthcare professionals. Issues like patient autonomy, economy, and access to tests also need to be addressed.

Perception and knowledge of pharmacogenetics among Brazilian psychiatrists

Pharmacogenetics (PGx) can optimize drug therapy in psychiatry and is particularly important in admixed populations. Here we developed and successfully validated a questionnaire for assessing the perception and knowledge of PGx among Brazilian psychiatrists. Overall, the participants showed some familiarity with PGx. Most psychiatrists reported to have knowledge of PGx and recognized its usefulness in psychiatry; however, they declared concerns regarding PGx education, the request of tests and their interpretation, cost-effectiveness, and ethical issues. PGx testing is relatively prevalent in their clinical practice, but education on the topic is lacking. Bivariate analysis revealed significant associations. Psychiatrists > 40 years of age more frequently had a positive perception of other clinicians' familiarity with PGx. Psychiatrists in private health services showed less self-reported competency in the use of PGx testing. Furthermore, women had better perception of PGx education. The present study adds knowledge about PGx in psychiatry and encourages the development of educational and training resources for PGx to improve its clinical implementation.

What Are the Barriers and Enablers to the Implementation of Pharmacogenetic Testing in Mental Health Care Settings?

In psychiatry, the selection of antipsychotics and antidepressants is generally led by a trial-and-error approach. The prescribing of these medications is complicated by sub-optimal efficacy and high rates of adverse drug reactions (ADRs). These both contribute to poor levels of adherence. Pharmacogenetics (PGx) considers how genetic variation can influence an individual’s response to a drug. Pharmacogenetic testing is a tool that could aid clinicians when selecting psychotropic medications, as part of a more personalized approach to prescribing. This may improve the use of and adherence to these medications. Yet to date, the implementation of PGx in mental health environments in the United Kingdom has been slow. This review aims to identify the current barriers and enablers to the implementation of PGx in psychiatry and determine how this can be applied to the uptake of PGx by NHS mental health providers. A systematic searching strategy was developed, and searches were carried out on the PsychInfo, EmBase, and PubMed databases, yielding 11 appropriate papers. Common barriers to the implementation of PGx included cost, concerns over incorporation into current workflow and a lack of knowledge about PGx; whilst frequent enablers included optimism that PGx could lead to precision medicine, reduce ADRs and become a more routine part of psychiatric clinical care. The uptake of PGx in psychiatric care settings in the NHS should consider and overcome these barriers, while looking to capitalize on the enablers identified in this review.

Barriers to clinical adoption of pharmacogenomic testing in psychiatry: a critical analysis

Pharmacogenomics (PGx) is the study of genetic influences on an individual's response to medications. Improvements in the quality and quantity of PGx research over the past two decades have enabled the establishment of commercial markets for PGx tests. Nevertheless, PGx testing has yet to be adopted as a routine practice in clinical care. Accordingly, policy regulating the commercialization and reimbursement of PGx testing is in its infancy. Several papers have been published on the topic of challenges, or 'barriers' to clinical adoption of this healthcare innovation. However, many do not include recent evidence from randomized controlled trials, economic utility studies, and qualitative assessments of stakeholder opinions. The present paper revisits the most cited barriers to adoption of PGx testing: evidence for clinical utility, evidence for economic effectiveness, and stakeholder awareness. We consider these barriers in the context of reviewing PGx literature published over the past two decades and emphasize data from commercial PGx testing companies, since they have published the largest datasets. We conclude with a discussion of existing limitations to PGx testing and recommendations for progress.

Multisite evaluation of institutional processes and implementation determinants for pharmacogenetic testing to guide antidepressant therapy

There is growing interest in utilizing pharmacogenetic (PGx) testing to guide antidepressant use, but there is lack of clarity on how to implement testing into clinical practice. We administered two surveys at 17 sites that had implemented or were in the process of implementing PGx testing for antidepressants. Survey 1 collected data on the process and logistics of testing. Survey 2 asked sites to rank the importance of Consolidated Framework for Implementation Research (CFIR) constructs using best‐worst scaling choice experiments. Of the 17 sites, 13 had implemented testing and four were in the planning stage. Thirteen offered testing in the outpatient setting, and nine in both outpatient/inpatient settings. PGx tests were mainly ordered by psychiatry (92%) and primary care (69%) providers. CYP2C19 and CYP2D6 were the most commonly tested genes. The justification for antidepressants selected for PGx guidance was based on Clinical Pharmacogenetics Implementation Consortium guidelines (94%) and US Food and Drug Administration (FDA; 75.6%) guidance. Both institutional (53%) and commercial laboratories (53%) were used for testing. Sites varied on the methods for returning results to providers and patients. Sites were consistent in ranking CFIR constructs and identified patient needs/resources, leadership engagement, intervention knowledge/beliefs, evidence strength and quality, and the identification of champions as most important for implementation. Sites deployed similar implementation strategies and measured similar outcomes. The process of implementing PGx testing to guide antidepressant therapy varied across sites, but key drivers for successful implementation were similar and may help guide other institutions interested in providing PGx‐guided pharmacotherapy for antidepressant management.

Review of Pharmacokinetics and Pharmacogenetics in Atypical Long-Acting Injectable Antipsychotics

Over the last two decades, pharmacogenetics and pharmacokinetics have been increasingly used in clinical practice in Psychiatry due to the high variability regarding response and side effects of antipsychotic drugs. Specifically, long-acting injectable (LAI) antipsychotics have different pharmacokinetic profile than oral formulations due to their sustained release characteristics. In addition, most of these drugs are metabolized by CYP2D6, whose interindividual genetic variability results in different metabolizer status and, consequently, into different plasma concentrations of the drugs. In this context, there is consistent evidence which supports the use of therapeutic drug monitoring (TDM) along with pharmacogenetic tests to improve safety and efficacy of antipsychotic pharmacotherapy. This comprehensive review aims to compile all the available pharmacokinetic and pharmacogenetic data regarding the three major LAI atypical antipsychotics: risperidone, paliperidone and aripiprazole. On the one hand, CYP2D6 metabolizer status influences the pharmacokinetics of LAI aripiprazole, but this relation remains a matter of debate for LAI risperidone and LAI paliperidone. On the other hand, developed population pharmacokinetic (popPK) models showed the influence of body weight or administration site on the pharmacokinetics of these LAI antipsychotics. The combination of pharmacogenetics and pharmacokinetics (including popPK models) leads to a personalized antipsychotic therapy. In this sense, the optimization of these treatments improves the benefit–risk balance and, consequently, patients’ quality of life.

Pharmacogenomic-based personalized medicine: Multistakeholder perspectives on implementational drivers and barriers in the Canadian healthcare system

Pharmacogenomics (PGx)-based personalized medicine (PM) is increasingly utilized to guide treatment decisions for many drug-disease combinations. Notably, London Health Sciences Centre (LHSC) has pioneered a PGx program that has become a staple for London-based specialists. Although implementational studies have been conducted in other jurisdictions, the Canadian healthcare system is understudied. Herein, the multistakeholder perspectives on implementational drivers and barriers are elucidated. Using a mixed-method qualitative model, key stakeholders, and patients from LHSC's PGx-based PM clinic were interviewed and surveyed, respectively. Interview transcripts were thematically analyzed in a stepwise process of customer profiling, value mapping, and business model canvasing. Value for LHSC located specialist users of PGx was driven by the quick turnaround time, independence of the PGx clinic, and the quality of information. Engagement of external specialists was only limited by access and awareness, whereas other healthcare nonusers were limited by education and applicability. The major determinant of successful adoption at novel sites were institutional champions. Patients valued and approved of the service, expressed a general willingness to pay, but often traveled far to receive genotyping. This paper discusses the critical pillars of education, awareness, advocacy, and efficiency required to address implementation barriers to healthcare service innovation in Canada. Further adoption of PGx practices into Canadian hospitals is an important factor for advancing system-level changes in care delivery, patient experiences, and outcomes. The findings in this paper can help inform efforts to advance clinical PGx practices, but also the potential adoption and implementation of other innovative healthcare service solutions.

Physicians' Knowledge and Attitudes Regarding Point-of-Care Pharmacogenetic Testing: A Hospital-Based Cross-Sectional Study

Introduction

Pharmacogenetic testing (PGx) is a diagnostic technique used by physicians to determine the possible reactions of patients to drug treatment on the basis of their genetic makeup. The aim of this study was to determine the impact of physicians’ awareness, attitudes, and sociodemographics on the adoption of point-of-care (POC) PGx testing as a diagnostic method, as well as the impact of their knowledge, attitudes, and sociodemographics on its adoption.

Methods

A cross-sectional survey of 200 physicians and medical trainees working at the Clinics of King Abdullah University Hospital in Jordan was performed. Data on sociodemographics, knowledge and attitudes concerning PGx testing, genetic information sources, and barriers to POC-PGx testing adoption were gathered.

Results

Participants’ perceived knowledge of the role of PGx testing in therapeutic decision-making was rated as “Excellent” (1.9%), “Very Good” (19.4%), “Good” (34.4%), “Fair” (32.5%), and “Poor” (11.9%). Physicians’ actual knowledge of PGx testing was adequate (mean=3.56 out of 7, SD=1.2), but their attitudes were generally favorable (mean=3.64 out of 5.00, SD=0.52). According to Rogers’ theory, many variables (eg, perceived need, relative advantage, compatibility) had a significant impact on physicians’ willingness to endorse POC-PGx testing.

Discussion

The majority of physicians stated that they were unaware of PGx testing. Physicians’ perceived knowledge of POC-PGx testing, however, was higher than those who participated in other studies. Participants were optimistic about the future benefits of PGx testing in prescribing effective medications and reducing potential side effects, which were consistent with previous studies. Physicians’ willingness to accept and implement POC-PGx testing was hampered by a lack of PGx expertise, as well as concerns about patient confidentiality, employability, and insurability. More training and genetic courses are needed, according to the majority of participants.

Acceptability of Pharmacogenetic Testing among French Psychiatrists, a National Survey

Psychiatric disorder management is based on the prescription of psychotropic drugs. Response to them remains often insufficient and varies from one patient to another. Pharmacogenetics explain part of this variability. Pharmacogenetic testing is likely to optimize the choice of treatment and thus improve patients’ care, even if concerns and limitations persist. This practice of personalized medicine is not very widespread in France. We conducted a national survey to evaluate the acceptability of this tool by psychiatrists and psychiatry residents in France, and to identify factors associated with acceptability and previous use. The analysis included 397 observations. The mean acceptability score was 10.70, on a scale from 4 to 16. Overall acceptability score was considered as low for 3.0% of responders, intermediate for 80.1% and high for 16.9%. After regression, the remaining factors influencing acceptability independently of the others were prescription and training history and theoretical approach. The attitude of our population seems to be rather favorable, however, obvious deficiencies have emerged regarding perceived skills and received training. Concerns about the cost and delays of tests results also emerged. According to our survey, one of the keys to overcoming the barriers encountered in the integration of pharmacogenetics seems to be the improvement of training and the provision of information to practitioners.

Approaches to assessing the provider experience with clinical pharmacogenomic information: a scoping review

PURPOSE

Barriers to the implementation of pharmacogenomics in clinical practice have been thoroughly discussed over the past decade.

METHODS

The objective of this scoping review was to characterize the peer-reviewed literature surrounding the experiences and actions of prescribers, pharmacists, or genetic counselors when using pharmacogenomic information in real-world or hypothetical research settings.

RESULTS

A total of 33 studies were included in the scoping review. The majority of studies were conducted in the United States (70%), used quantitative or mixed methods (79%) with physician or pharmacist respondents (100%). The qualitative content analysis revealed five major methodological approaches: hypothetical clinical case scenarios, real-world studies evaluating prescriber response to recommendations or alerts, cross-sectional quantitative surveys, cross-sectional qualitative surveys/interviews, and a quasi-experimental real-world study.

CONCLUSION

The findings of this scoping review can guide further research on the factors needed to successfully integrate pharmacogenomics into clinical care.

Pharmacogenetics in Psychiatry: Perceived Value and Opinions in a Chilean Sample of Practitioners

Use of pharmacogenetics (PGx) testing to guide clinical decisions is growing in developed countries. Published guidelines for gene–drug pair analysis are available for prescriptions in psychiatry, but information on their utilization, barriers, and health outcomes in Latin America is limited. As a result, this work aimed at exploring current use, opinions, and perceived obstacles on PGx testing among psychiatrists in Chile, via an online, anonymous survey. Among 123 respondents (5.9% of registered psychiatrists in the country), 16.3% reported ever requesting a PGx test. The vast majority (95%) of tests were ordered by clinicians practicing in the Metropolitan Region of Santiago. Having more than 20 years in practice was positively associated with prior use of PGx (p 0.02, OR 3.74 (1.19–11.80)), while working in the public health system was negatively associated (OR 0.30 (0.10–0.83)). Perceived barriers to local implementation included insufficient evidence of clinical utility, limited clinicians’ knowledge on PGx and on test availability, and health systems’ issues, such as costs and reimbursement. Despite the recognition of these barriers, 80% of respondents asserted that it is likely that they will incorporate PGx tests in their practice in the next five years. Given these results, we propose next steps to facilitate implementation such as further research in health outcomes and clinical utility of known and novel clinically actionable variants, growth in local sequencing capabilities, education of clinicians, incorporation of clinical decision support tools, and economic evaluations, all in local context.

PGx in psychiatry: Patients' knowledge, interest, and uncertainty management preferences in the context of pharmacogenomic testing

OBJECTIVE

Pharmacogenomic testing (PGx) is expanding into psychiatric care. PGx could potentially offer a unique benefit to psychiatric patients, providing information about patients' reaction to medications that could reduce the time and financial burdens of drug optimization. The aims of this study were to: (1) examine psychiatry patients' familiarity and interest in PGx, and (2) explore how Uncertainty Management Theory relates to PGx testing in psychiatry.

METHOD

We surveyed psychiatric patients, measuring their PGx familiarity and interest, attitudes toward PGx testing, and preference for managing illness uncertainty.

RESULTS

We analyzed data from 598 patients. Patients' familiarity of PGx was low, but interest was high. Thirty percent of patients were familiar with the test from communication with their healthcare provider or their own online health information seeking. A preference for seeking information was a significant positive predictor of testing interest (p < .001).

CONCLUSION

Psychiatric patients were interested in PGx testing, regardless of their uncertainty management preferences.

PRACTICE IMPLICATIONS

This study is one of the first to examine psychiatric patients' perspectives on PGx testing in mental health care. Our findings show that psychiatric patients are interested in the test and are familiar enough with PGx to be included in future research on the topic.

Review and Consensus on Pharmacogenomic Testing in Psychiatry

The implementation of pharmacogenomic (PGx) testing in psychiatry remains modest, in part due to divergent perceptions of the quality and completeness of the evidence base and diverse perspectives on the clinical utility of PGx testing among psychiatrists and other healthcare providers. Recognizing the current lack of consensus within the field, the International Society of Psychiatric Genetics assembled a group of experts to conduct a narrative synthesis of the PGx literature, prescribing guidelines, and product labels related to psychotropic medications as well as the key considerations and limitations related to the use of PGx testing in psychiatry. The group concluded that to inform medication selection and dosing of several commonly-used antidepressant and antipsychotic medications, current published evidence, prescribing guidelines, and product labels support the use of PGx testing for 2 cytochrome P450 genes (CYP2D6, CYP2C19). In addition, the evidence supports testing for human leukocyte antigen genes when using the mood stabilizers carbamazepine (HLA-A and HLA-B), oxcarbazepine (HLA-B), and phenytoin (CYP2C9, HLA-B). For valproate, screening for variants in certain genes (POLG, OTC, CSP1) is recommended when a mitochondrial disorder or a urea cycle disorder is suspected. Although barriers to implementing PGx testing remain to be fully resolved, the current trajectory of discovery and innovation in the field suggests these barriers will be overcome and testing will become an important tool in psychiatry.

Four Actionable Bottlenecks and Potential Solutions to Translating Psychiatric Genetics Research: An Expert Review

BACKGROUND

Psychiatric genetics has had limited success in translational efforts. A thorough understanding of the present state of translation in this field will be useful in the facilitation and assessment of future translational progress.

PURPOSE

A narrative literature review was conducted. Combinations of 3 groups of terms were searched in EBSCOhost, Google Scholar, and PubMed. The review occurred in multiple steps, including abstract collection, inclusion/exclusion criteria review, coding, and analysis of included papers.

RESULTS

One hundred and fourteen articles were analyzed for the narrative review. Across those, 4 bottlenecks were noted that, if addressed, may provide insights and help improve and increase translation in the field of psychiatric genetics. These 4 bottlenecks are emphasizing linear translational frameworks, relying on molecular genomic findings, prioritizing certain psychiatric disorders, and publishing more reviews than experiments.

CONCLUSIONS

These entwined bottlenecks are examined with one another. Awareness of these bottlenecks can inform stakeholders who work to translate and/or utilize psychiatric genetic information. Potential solutions include utilizing nonlinear translational frameworks as well as a wider array of psychiatric genetic information (e.g., family history and gene-environment interplay) in this area of research, expanding which psychiatric disorders are considered for translation, and when possible, conducting original research. Researchers are urged to consider how their research is translational in the context of the frameworks, genetic information, and psychiatric disorders discussed in this review. At a broader level, these efforts should be supported with translational efforts in funding and policy shifts.

Physicians' Attitudes and Ethical Obligations to Pharmacogenetic Testing

INTRODUCTION

Despite the increased utilization of pharmacogenetic (PGt) testing to guide drug therapy, little is known about the ethical challenges posed by the use of these genetic tools.

METHODS

This cross-sectional study aimed to address ethical issues related to ancillary genetic information, consent forms, and potential confidentiality breaches from physicians' perspectives. A questionnaire was administered to all practicing physicians working in KAUH.

RESULTS

Almost 49% and 65% of physicians were willing to recommend PGt testing for adult and pediatric patients, respectively. The findings showed that physicians attitudes towards the clinical utility of PGt testing became more preceptive. The majority (73.7%) indicated that PGt testing should not be treated as other routine laboratory tests. The finding also focused on potential conflicts regarding ancillary genetic information, in which 78.8% indicated that they would like to preserve the confidentiality and privacy of the patients and only 14.4% of physicians did not feel obligated to let patients know about any future risk that might be uncovered using PGt testing. The findings showed that collecting both verbal and written consents was imperative prior to testing. Seriousness and predictability of the diseases were reported to be legitimate circumstances that allow disclosure of genetic information.

DISCUSSION

Unless the field of PGt testing addresses the ethical challenges that might be encountered during PGt treatment, these issues might influence its acceptance in routine clinical settings. Establishing a minimal set of ethical standards may help emphasize the role of physicians and thus facilitate the implementation of PGt tests.

The effect of CYP2D6 variation on antipsychotic-induced hyperprolactinaemia: a systematic review and meta-analysis

Hyperprolactinemia is a known adverse drug reaction to antipsychotic treatment. Antipsychotic blood levels are influenced by cytochrome P450 enzymes, primarily CYP2D6. Variation in CYP450 genes may affect the risk of antipsychotic-induced hyperprolactinemia. We undertook a systematic review and meta-analysis to assess whether CYP2D6 functional genetic variants are associated with antipsychotic-induced hyperprolactinemia. The systematic review identified 16 relevant papers, seven of which were suitable for the meta-analysis (n = 303 participants including 134 extreme metabolisers). Participants were classified into four phenotype groups as poor, intermediate, extensive, and ultra-rapid metabolisers. A random effects meta-analysis was used and Cohen's d calculated as the effect size for each primary study. We found no significant differences in prolactin levels between CYP2D6 metabolic groups. Current evidence does not support using CYP2D6 genotyping to reduce risk of antipsychotic-induced hyperprolactinemia. However, statistical power is limited. Future studies with larger samples and including a range of prolactin-elevating drugs are needed.

Genetic testing for CYP2D6 and CYP2C19 suggests improved outcome for antidepressant and antipsychotic medication

Individuals carrying genetic variants that result in non-extensive CYP2D6 and CYP2C19 enzyme activity seem to be more prone to non-response and side-effects of psychotropic medications. Therefore, tailoring prescriptions using genetic information may improve patient outcomes. This study examined treatment outcome in psychiatric care after CYP2D6 and CYP2C19 genetic information was provided to patients and physicians. CYP2D6 and CYP2C19 genotyping, assessment of side effects and medical histories were obtained from 80 subjects who were prescribed either antidepressant or antipsychotic medications. Our measure of outcome was mainly physicians' opinions however UKU side effects scores were also used. For CYP2D6, we calculated an activity score based on genotype and psychiatric medications. Correlation analysis was performed for CYP2D6 activity scores and UKU scores. Overall, we received supportive responses from physicians who enrolled patients in our study. Notably, while almost every fourth physician reported improvement in patient outcome, not a single physician indicated that their patient's symptoms worsened after they had used a pharmacogenetic report to guide treatment. We did not observe statistically significant differences in side effects. Overall, our results suggest improved patient outcome following pharmacogenetic testing; nonetheless, more research is required to assess the exact benefit of pharmacogenetics in clinical practice.

Pharmacogenetics and Depression: A Critical Perspective

Depression leads the higher personal and socio-economical burden within psychiatric disorders. Despite the fact that over 40 antidepressants (ADs) are available, suboptimal response still poses a major challenge and is thought to be partially a result of genetic variation. Pharmacogenetics studies the effects of genetic variants on treatment outcomes with the aim of providing tailored treatments, thereby maximizing efficacy and tolerability. After two decades of pharmacogenetic research, variants in genes coding for the cytochromes involved in ADs metabolism (CYP2D6 and CYP2C19) are now considered biomarkers with sufficient scientific support for clinical application, despite the lack of conclusive cost/effectiveness evidence. The effect of variants in genes modulating ADs mechanisms of action (pharmacodynamics) is still controversial, because of the much higher complexity of ADs pharmacodynamics compared to ADs metabolism. Considerable progress has been made since the era of candidate gene studies: the genomic revolution has made possible to assess genetic variance on an unprecedented scale, throughout the whole genome, and to analyze the cumulative effect of different variants. The results have revealed key information on the biological mechanisms mediating ADs effect and identified hypothetical new pharmacological targets. They also paved the way for future availability of polygenic pharmacogenetic panels to predict treatment outcome, which are expected to explain much higher variance in ADs response compared to CYP2D6 and CYP2C19 only. As the demand and availability of AD pharmacogenetic testing is projected to increase, it is important for clinicians to keep abreast of this evolving area to facilitate informed discussions with their patients.

A pharmacogenetic intervention for the improvement of the safety profile of antipsychotic treatments

Antipsychotic drugs fail to achieve adequate response in 30-50% of treated patients and about 50% of them develop severe and lasting side effects. Treatment failure results in poorer prognosis with devastating repercussions for the patients, carers and broader society. Our study evaluated the clinical benefits of a pharmacogenetic intervention for the personalisation of antipsychotic treatment. Pharmacogenetic information in key CYP polymorphisms was used to adjust clinical doses in a group of patients who started or switched treatment with antipsychotic drugs (PharmG+, N = 123), and their results were compared with those of a group of patients treated following existing clinical guides (PharmG-, N = 167). There was no evidence of significant differences in side effects between the two arms. Although patients who had their antipsychotic dose adjusted according to CYPs polymorphisms (PharmG+) had a bigger reduction in side effects than those treated as usual (PharmG-), the difference was not statistically significant (p > 0.05 for all comparisons). However, PharmG+ patients treated with CYP2D6 substrates that were carriers of CYP2D6 UMs or PMs variants showed a significantly higher improvement in global, psychic and other UKU side effects than PharmG- patients (p = 0.02, p = 0.05 and p = 0.01, respectively). PharmG+ clozapine treated patients with CYP1A2 or CYP2C19 UM and PMs variants also showed higher reductions in UKU scores than PharmG- clozapine patients in general. However, those differences were not statistically significant. Pharmacogenetic interventions may improve the safety of antipsychotic treatments by reducing associated side effects. This intervention may be particularly useful when considering treatment with antipsychotics with one major metabolic pathway, and therefore more susceptible to be affected by functional variants of CYP enzymes.

[Pharmacogenetics in psychiatry: state of the art]

In this article, the current literature on pharmacogenetics of antidepressants, antipsychotics and lithium are summarized by the section of Neurobiology and Genetics of the German Society of Psychiatry, Psychotherapy and Neurology (DGPPN). The publications of international expert groups and regulatory authorities are reviewed and discussed. In Germany, a statement on pharmacogenetics was also made by the gene diagnostics committee of the Ministry of Health. The DGPPN supports two recommendations: 1) to perform CYP2D6 genetic testing prior to prescription of tricyclic antidepressants and 2) to determine the HLA-B*1502 genotype in patients of Asian origin before using carbamazepine. The main obstacle for a broad application of pharmacogenetic tests in psychiatry remains the lack of large prospective studies, for both single gene-drug pair and cobinatorial pharmacogenetic tests, to evaluate the benefits of genetic testing. Psychiatrists, geneticists and funding agencies are encouraged to increase their efforts for the future benefit of psychiatric patients.

The role of genetics and genomics in clinical psychiatry

The enormous successes in the genetics and genomics of many diseases have provided the basis for the advancement of precision medicine. Thus, the detection of genetic variants associated with neuropsychiatric disorders, as well as treatment outcome, has raised growing expectations that these findings could soon be translated into the clinic to improve diagnosis, the prediction of disease risk and individual response to drug therapy. In this article, we will provide an introduction to the search for genes involved in psychiatric illness and summarize the present findings in major psychiatric disorders. We will review the genetic variants in genes encoding drug metabolizing enzymes and specific drug targets which were found to be associated with variable drug response and severe side effects. We will evaluate the clinical translatability of these findings, whether there is currently any role for genetic testing and in this context, make valuable sources of information available to the clinician seeking guidance and advice in this rapidly developing field of psychiatric genetics.

Towards the integration of pharmacogenetics in psychiatry: a minimum, evidence-based genetic testing panel

PURPOSE OF REVIEW

The implementation of pharmacogenetic testing in psychiatry is underway but is not yet standard protocol. Barriers to pharmacogenetics becoming standard practice are the lack of translation of evidence-based recommendations and standardization of genetic testing panels. As for the latter, there are currently no regulatory standards related to the gene and allele content of testing panels used to derive medication selection and dosing advice. To address these barriers, we summarize the current gene-drug interaction knowledgebase and proposed a minimum gene and allele set for pharmacogenetic testing in psychiatry.

RECENT FINDINGS

The Pharmacogenomics Knowledgebase has cataloged 448 gene-drug interactions relevant to psychiatry based on the current scientific literature, drug labels, and pharmacogenetic-based implementation guidelines. A majority of these interactions involved two cytochrome P450 enzymes (CYP2D6 and CYP2C19) and antidepressant medications, however, CYP2C9, HLA-A, and HLA-B are relevant to mood stabilizers/anticonvulsants.

SUMMARY

On the basis of evidence base, we proposed a minimum gene and allele set for pharmacogenetic testing in psychiatry that includes 16 variant alleles within five genes (CYP2C9, CYP2C19, CYP2D6, HLA-A, HLA-B). The intent is to assist clinicians in judging the gene and allele content of pharmacogenetic tests and to facilitate pharmacogenetic testing as a standard protocol and companion tool for psychotropic medication selection and dosing.

Pharmacogenetic tests and depressive symptom remission: a meta-analysis of randomized controlled trials

Aim: To conducted a systematic review and meta-analysis of prospective, randomized controlled trials (RCTs) that examined pharmacogenetic-guided decision support tools (DSTs) relevant to depressive symptom remission in major depressive disorder (MDD). Patients & methods: Random-effects meta-analysis was performed on RCTs that examined the effect of DSTs on remission rates in MDD. RCT quality was assessed using the Cochrane Collaboration Criteria. Results & conclusion: A total of 1737 eligible subjects from five RCTs were examined. Individuals receiving pharmacogenetic-guided DST therapy (n = 887) were 1.71 (95% CI: 1.17–2.48; p = 0.005) times more likely to achieve symptom remission relative to individuals who received treatment as usual (n = 850). Pharmacogenetic-guided DSTs might improve symptom remission among those with MDD.

Systematic evaluation of commercial pharmacogenetic testing in psychiatry: a focus on CYP2D6 and CYP2C19 allele coverage and results reporting

OBJECTIVE

The aim of this study was to systematically assess commercial pharmacogenetic tests relevant to prescribing in psychiatry, with specific attention on CYP2D6 and CYP2C19 star allele coverage as well as compliance with consensus recommendations for pharmacogenetic test result reporting.

MATERIALS AND METHODS

The CYP2D6 and CY2C19 star (*) allele contents of 20 pharmacogenetic test panels were compared and their test results reports were evaluated on the basis of consensus reporting recommendations published by The Centers for Disease Control and Prevention as well as the Clinical Pharmacogenetics Implementation Consortium.

RESULTS

Most test panels included the major CYP2D6 (*2, *4, *5, *10, *17) and CYP2C19 (*2, *3, *17) alleles, but no two test panels contained the same combination of CYP2D6 and CYP2C19 alleles. Of the 20 pharmacogenetic reports that we evaluated, none fulfilled all the recommendations and no recommendation was fulfilled by all tests.

CONCLUSION

Consensus has yet to be reached on which CYP2D6 and CYP2C19 star alleles to include on pharmacogenetic testing panels and pharmacogenetic results reporting could be considerably improved. Collaboration between test manufacturers and end-users is required to narrow the gap between the availability and integration of these pharmacogenetic-based decision-support tools into routine practice.

A theory-informed systematic review of clinicians' genetic testing practices

This systematic literature review investigates factors impacting on clinicians' decisions to offer genetic tests in their practice, and maps them to a theoretical behaviour change framework. Better understanding of these factors will inform the design of effective interventions to integrate genomics tests into clinical care. We conducted a narrative synthesis of empirical research of medical specialists' perspectives on and experiences of offering genetic tests to their patients. This review was based upon the PRISMA statement and guidelines for reviewing qualitative research. Four electronic data sources were searched-MEDLINE, EMBASE, CINAHL, PubMed. Studies were independently assessed by two authors. Content analysis was applied to map the findings of included studies to a framework validated for behaviour and implementation research, the Theoretical Domains Framework (TDF). The TDF describes 14 factors known to influence behaviour and has been applied in diverse clinical settings to understand and/or modify health professional behaviour. Thirty-four studies published in 39 articles met inclusion and quality criteria. Most studies were published after 2011 (54%), Northern American (82%), quantitative in design (68%) and addressed familial cancer genetic tests (53%). Of the 14 TDF factors, 13 were identified. The three most common factors were: Environmental Context and Resources (n = 33), Beliefs about Consequences (n = 26), and Knowledge (n = 23). To support the adoption of genomic tests beyond specialist services, nuanced interventions targeting considerations beyond clinician education are needed. For instance, interventions addressing organisational constraints which may restrict clinicians' ability to offer genomic tests are required alongside those targeting factors intrinsic to the clinician.

Testing positive for a genetic predisposition to depression magnifies retrospective memory for depressive symptoms

OBJECTIVE

Depression, like other mental disorders and health conditions generally, is increasingly construed as genetically based. This research sought to determine whether merely telling people that they have a genetic predisposition to depression can cause them to retroactively remember having experienced it.

METHOD

U.S. adults (men and women) were recruited online to participate (Experiment 1: N = 288; Experiment 2: N = 599). After conducting a test disguised as genetic screening, we randomly assigned some participants to be told that they carried elevated genetic susceptibility to depression, whereas others were told that they did not carry this genetic liability or were told that they carried elevated susceptibility to a different disorder. Participants then rated their experience of depressive symptoms over the prior 2 weeks on a modified version of the Beck Depression Inventory-II.

RESULTS

Participants who were told that their genes predisposed them to depression generally reported higher levels of depressive symptomatology over the previous 2 weeks, compared to those who did not receive this feedback.

CONCLUSIONS

Given the central role of self-report in psychiatric diagnosis, these findings highlight potentially harmful consequences of personalized genetic testing in mental health. (PsycINFO Database Record

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

Clinicians still employ a "trial-and-error" approach to optimizing treatment regimens for late-life depression (LLD). With LLD affecting a significant and growing segment of the population, and with only about half of older adults responsive to antidepressant therapy, there is an urgent need for a better treatment paradigm. Pharmacogenetic decision support tools (DSTs), which are emerging technologies that aim to provide clinically actionable information based on a patient's genetic profile, offer a promising solution. Dozens of DSTs have entered the market in the past 15 years, but with varying level of empirical evidence to support their value. In this clinical review, we provide a critical analysis of the peer-reviewed literature on DSTs for major depression management. We then discuss clinical considerations for the use of these tools in treating LLD, including issues related to test interpretation, timing, and patient perspectives. In adult populations, newer generation DSTs show promise for the treatment of major depression. However, there are no primary clinical trials in LLD cohorts. Independent and comparative clinical trials are needed.

Genetic testing as a supporting tool in prescribing psychiatric medication: Design and protocol of the IMPACT study

OBJECTIVE

Pharmacotherapy is one of the primary treatments for psychiatric disorders. Given the variation in individual response, a more personalized approach is needed. This paper will discuss methods for user-friendly referrals, recruitment criteria, data storage and dissemination, biological sample and clinical questionnaire collection, and advertising.

METHODS

The Individualized Medicine: Pharmacogenetics Assessment and Clinical Treatment (IMPACT) study is one of the first to use pharmacogenetic testing on a large scale in psychiatry as a tool to predict individual drug response and tolerability. As IMPACT's eligibility criteria includes all diagnoses and comorbidities, the participant population will reflect the diversity amongst mental health consumers. IMPACT's innovative study design will demonstrate the utility of this testing within the health care system.

RESULTS

IMPACT has successfully implemented pharmacogenetic testing on a relatively large scale, and in both tertiary level and primary care settings. It represents a novel approach to psychiatric care and from its initial stages the design has evolved to accommodate the nature and needs of the health care community.

CONCLUSION

It is anticipated that IMPACT will continue to demonstrate the feasibility of pharmacogenetic testing and facilitate its introduction and implementation in routine healthcare practice.

Integrating pharmacogenetic testing into primary care

Introduction

Pharmacogenetic (PGx) testing has greatly expanded due to enhanced understanding of the role of genes in drug response and advances in DNA-based testing technology development. As many primary care visits result in a prescription, the use of PGx testing may be particularly beneficial in this setting. However, integration of PGx testing may be limited as no uniform approach to delivery of tests has been established and providers are ill-prepared to integrate PGx testing into routine care.

Areas covered

In this paper, the readiness of primary care practitioners are reviewed as well as strategies to address these barriers based on published research and ongoing activities on education and implementation of PGx testing.

Expert Commentary

Widespread integration of PGx testing will warrant continued education and point-of-care decisional support. Primary care providers may also benefit from consultation services or team-based care with laboratory medicine specialists, pharmacists, and genetic counselors.

The role of depression pharmacogenetic decision support tools in shared decision making

Patients discontinue antidepressant medications due to lack of knowledge, unrealistic expectations, and/or unacceptable side effects. Shared decision making (SDM) invites patients to play an active role in their treatment and may indirectly improve outcomes through enhanced engagement in care, adherence to treatment, and positive expectancy of medication outcomes. We believe decisional aids, such as pharmacogenetic decision support tools (PDSTs), facilitate SDM in the clinical setting. PDSTs may likewise predict drug tolerance and efficacy, and therefore adherence and effectiveness on an individual-patient level. There are several important ethical considerations to be navigated when integrating PDSTs into clinical practice. The field requires greater empirical research to demonstrate clinical utility, and the mechanisms thereof, as well as exploration of the ethical use of these technologies.

Antidepressant prescribing in the precision medicine era: a prescriber's primer on pharmacogenetic tools

About half of people who take antidepressants do not respond and many experience adverse effects. These detrimental outcomes are in part a result of the impact of an individual's genetic profile on pharmacokinetics and pharmcodynamics. If known and made available to clinicians, this could improve decision-making and antidepressant therapy outcomes. This has spurred the development of numerous pharmacogenetic-based decision support tools. In this article, we provide an overview of pharmacogenetic decision support tools, with particular focus on tools relevant to antidepressants. We briefly describe the evolution and current state of antidepressant pharmacogenetic decision support tools in clinical practice, followed by the evidence-base for their use. Finally, we present a series of considerations for clinicians contemplating use of these tools and discuss the future of antidepressant pharmacogenetic decision support tools.

Genetics of Common Antipsychotic-Induced Adverse Effects

The effectiveness of antipsychotic drugs is limited due to accompanying adverse effects which can pose considerable health risks and lead to patient noncompliance. Pharmacogenetics (PGx) offers a means to identify genetic biomarkers that can predict individual susceptibility to antipsychotic-induced adverse effects (AAEs), thereby improving clinical outcomes. We reviewed the literature on the PGx of common AAEs from 2010 to 2015, placing emphasis on findings that have been independently replicated and which have additionally been listed to be of interest by PGx expert panels. Gene-drug associations meeting these criteria primarily pertain to metabolic dysregulation, extrapyramidal symptoms (EPS), and tardive dyskinesia (TD). Regarding metabolic dysregulation, results have reaffirmed HTR2C as a strong candidate with potential clinical utility, while MC4R and OGFR1 gene loci have emerged as new and promising biomarkers for the prediction of weight gain. As for EPS and TD, additional evidence has accumulated in support of an association with CYP2D6 metabolizer status. Furthermore, HSPG2 and DPP6 have been identified as candidate genes with the potential to predict differential susceptibility to TD. Overall, considerable progress has been made within the field of psychiatric PGx, with inroads toward the development of clinical tools that can mitigate AAEs. Going forward, studies placing a greater emphasis on multilocus effects will need to be conducted.