The promise and reality of pharmacogenetics in psychiatry

Effect of pharmacogenomic testing on pediatric mental health outcome: a 6-month follow-up

Aim: This retrospective, case-control study evaluated the effect of pharmacogenomic testing (PGT) on the management of pediatrics with anxiety, major depressive disorder (MDD) and attention-deficit/hyperactivity disorder (ADHD). Methods: The authors examined psychiatric diagnoses, medication histories, CYP450 profiles, SLC6A4, HTR2A, COMT and MTHFR. Results: The authors found no difference in clinical improvement between the two groups. However, the number of medication changes was significantly larger after PGT. The treatment response in MDD and anxiety was not different between the groups, while ADHD treatment response was substantially improved in PGT and correlated with COMT status. Conclusion: PGT had some value with ADHD with doubtful benefit for MDD or anxiety disorders. Accordingly, pediatric indications must be weighed against cost, utility and clinician experience. Limitations included sample size and selection bias.

Pharmacogenomics and Psychiatric Nursing

The treatment of mental illness is often done on a trial-and-error basis and achieving therapeutic benefits from a medication is not always guaranteed. Pharmacogenomics explores the role of gene-gene interactions and interindividual responses to a drug and may be promising in the guidance of pharmacotherapeutic options. In the present study, the impact of pharmacogenomic testing in management of mental health medication was investigated. Participants were identified at a local outpatient mental health facility through convenience sampling. Retrospective chart review included medication history, adverse drug reactions, pharmacogenomic history, and demographic data including insurance coverage. Chart review focused on six months pre- and post-pharmacogenomic for a comparison with the patient serving as their own control. Results indicate a high incidence of alterations in two specific cytochrome enzymes, CYP2D6 and CYP2C19. In total, 82% of the sample had variations with CYP2D6, while 64% of individuals had variations with CYP2C19. In total, 91% of patients tested received Medicaid or Medicare. Post-pharmacogenomic testing, all patient drug regimens were modified, and all reported less adverse side effects. Moreover, advanced practice nurse providers educated patients about the availability of genetic testing, initiated testing and provided care based on findings. These results demonstrate the utility of genetic testing in the realm of mental health. Future directions involve further exploring the benefits of pharmacogenomic testing in this vulnerable population.

Pharmacogenetic profile and major depressive and/or bipolar disorder treatment: a retrospective, cross-sectional study

Aim: To compare pharmacogenetic test predictions with self-reported treatment experience and side effect tolerability among patients with depression taking psychotherapeutic medications. Methods: Subjects completed a survey recalling medication effectiveness and side effects and then underwent pharmacogenetic testing. Results: Our 15 gene pharmacogenetic panel predicted efficacy (p < 0.001) but did not predict side effect tolerability (p = 0.70) in a group of 352 patients. The pharmacogenetic panel and reported efficacy corresponded 60% of the time and medication tolerability agreed 71% of the time. Conclusion: Pharmacogenetic testing may be a useful adjunct to predict efficacy of medications used to treat depression.

Shared and distinct alterations of white matter tracts in remitted and nonremitted patients with schizophrenia

Patients with schizophrenia do not usually achieve remission state even after adequate antipsychotics treatment. Previous studies found significant difference in white matter integrity between patients with good outcomes and those with poor outcomes, but difference is still unclear at individual tract level. This study aimed to use a systematic approach to identify the tracts that were associated with remission state in patients with schizophrenia. We evaluated 91 patients with schizophrenia (remitted, 50; nonremitted, 41) and 50 healthy controls through diffusion spectrum imaging. White matter tract integrity was assessed through an automatic tract-specific analysis method to determine the mean generalized fractional anisotropy (GFA) values of the 76 white matter tract bundles in each participant. Analysis of covariance among the 3 groups revealed 12 tracts that were significantly different in GFA values. Post-hoc analysis showed that compared with the healthy controls, the nonremission group had reduced integrity in all 12 tracts, whereas the remission group had reduced integrity in only 4 tracts. Comparison between the remission and nonremission groups revealed 4 tracts with significant difference (i.e., the right fornix, bilateral uncinate fasciculi, and callosal fibers connecting the temporal poles) even after adjusting age, sex, education year, illness duration, and medication dose. Furthermore, all the 4 tracts were correlated with negative symptoms scores of the positive and negative syndrome scale. In conclusion, our study identified the tracts that were associated with remission state of schizophrenia. These tracts might be a potential prognostic marker for the symptomatic remission in patients with schizophrenia.

Anticipating the Ethical Challenges of Psychiatric Genetic Testing

PURPOSE OF REVIEW

Genetic testing for mental illness is likely to become increasingly prevalent as the science behind it is refined. This article identifies anticipated ethical challenges for patients, psychiatrists, and genetic counselors and makes recommendations for addressing them.

RECENT FINDINGS

Many of the ethical challenges of psychiatric genetic testing are likely to stem from failures to comprehend the nature and implications of test results. Recent studies have identified gaps in the knowledge base of psychiatrists and genetic counselors, which limit their abilities to provide patients with appropriate education. A small number of studies have demonstrated the value of counseling in empowering patients to deal with relevant genetic information. Psychiatrists and other health professionals must be able to assist patients and families in making informed decisions about genetic testing and interpreting test results. Filling their knowledge gaps on these issues will be a critical step towards meeting these responsibilities.

A current snapshot of common genomic variants contribution in psychiatric disorders

In the past decade, numerous advances were achieved in psychiatric genetics. Particularly, the genome wide association studies (GWAS) have contributed to uncovering new genes and pathways associated to psychiatric disorders (PDs). At the same time, with increasing sample sizes in the GWAS, the polygenic risk score (PRS) promoted an additional tool for identification and evaluation the genetic risk quantitatively in PDs. This concept review presents the state of the art GWAS analysis and PRS focusing on the genetic underpinnings of PDs. © 2016 Wiley Periodicals, Inc.

An Individualized Approach to Treatment-Resistant Bipolar Disorder: A Case Series

CONTEXT

Treatment-resistant bipolar disorder (TRBD) is an increasingly prevalent, debilitating condition with substandard treatment outcomes. Polypharmacy has become the mainstay among practitioners though long-term efficacy of this method has not been adequately tested.

OBJECTIVE

Determine retrospectively if individualized, integrative treatment strategies applied while withdrawing pharmaceuticals were beneficial and safe among a TRBD clinic population.

DESIGN

A chart review was performed for six adult patients, treated in a private psychiatric practice. Data were collected regarding psychiatric diagnosis, hospitalizations, medications, side effects, substance abuse, and applied treatments.

RESULTS

Using individualized, integrative psychiatric treatment methods, the majority of medications were eliminated. Long-term remission was attained in all cases, defined as clinical stability with no discernable symptoms of bipolar disorder for at least one year.

CONCLUSIONS

Applying an integrative treatment approach, and eliminating most medications, provided lasting resolution of symptoms and side effects in a selected sample of TRBD outpatients. These data may provide the basis for future randomized, controlled trials.

Medication-free Alternatives for Long-term Maintenance of Bipolar Disorder: A Case Series

Psychopharmacological treatment has been the mainstay in long-term maintenance of bipolar disorder (BD) patients for the last 60 years. Conventionally accepted treatment options are primarily based on expert opinion rather than on well-executed, independently funded research. Investigation of maintaining patients without medications using treatment alternatives has been neglected. This clinical case series examines the outcomes of 7 BD patients who experienced a poor response or significant side effects with conventional treatment modalities. Patients were gradually and safely withdrawn from all medications. Treatment strategies were based on an individualized holistic approach using herbs, nutritional supplements, vitamins, amino acids, acupuncture, dietary recommendations, and behavioral modifications. Multiple treatment modalities were combined addressing the etiological causes for BD symptoms. Upon withdrawal from psychotropic medications, patients were free of medication-induced side effects and obtained psychiatric stability for at least 10 months. Further research is needed to investigate the long-term outcomes of BD treatment modalities based on well-defined successful outcome criteria, such as reduction in symptoms, improvement in quality of life, overall health outcomes, and cost effectiveness.

Pharmacogenetics informed decision making in adolescent psychiatric treatment: a clinical case report

Advances made in genetic testing and tools applied to pharmacogenetics are increasingly being used to inform clinicians in fields such as oncology, hematology, diabetes (endocrinology), cardiology and expanding into psychiatry by examining the influences of genetics on drug efficacy and metabolism. We present a clinical case example of an adolescent male with anxiety, attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder who did not tolerate numerous medications and dosages over several years in attempts to manage his symptoms. Pharmacogenetics testing was performed and DNA results on this individual elucidated the potential pitfalls in medication use because of specific pharmacodynamic and pharmacokinetic differences specifically involving polymorphisms of genes in the cytochrome p450 enzyme system. Future studies and reports are needed to further illustrate and determine the type of individualized medicine approach required to treat individuals based on their specific gene patterns. Growing evidence supports this biological approach for standard of care in psychiatry.

Patterns of variation influencing antipsychotic treatment outcomes in South African first-episode schizophrenia patients

AIM

Many antipsychotic pharmacogenetics studies have been performed examining candidate genes or known variation; however, our understanding of the genetic factors involved in antipsychotic pharmacogenetic traits remains limited.

MATERIALS & METHODS

A well-characterized cohort of first-episode schizophrenia (FES) patients was used to identify a subset of nonresponders and responders to antipsychotic treatment for exome sequencing (n = 11). The variation observed in the responders and nonresponders was subsequently compared and a prioritization strategy was employed to identify variants for genotyping in the entire FES cohort (n = 103) as well as an additional Xhosa schizophrenia cohort (n = 222).

RESULTS

Examination of coding variation revealed a potential role for rare loss-of-function variants in treatment response outcomes. One variant, rs11368509, was found to be weakly associated with better treatment outcomes in the FES cohort (p = 0.057) and the Xhosa schizophrenia cohort (p = 0.016). In addition, the majority of the loss-of-function variation that was considered likely to be involved in antipsychotic treatment response was either novel or rare in Asian and European populations.

CONCLUSION

This pilot study has highlighted the importance of exome sequencing for antipsychotic pharmacogenomics studies, particularly in African individuals. Furthermore, the results emphasize once again the complexity of antipsychotic pharmacogenomics and the need for future research.

Striking a balance in communicating pharmacogenetic test results: promoting comprehension and minimizing adverse psychological and behavioral response

OBJECTIVE

Pharmacogenetic (PGx) testing can provide information about a patient's likelihood to respond to a medication or experience an adverse event, and be used to inform medication selection and/or dosing. Promoting patient comprehension of PGx test results will be important to improving engagement and understanding of treatment decisions.

METHODS

The discussion in this paper is based on our experiences and the literature on communication of genetic test results for disease risk and broad risk communication strategies.

RESULTS

Clinical laboratory reports often describe PGx test results using standard terminology such as 'poor metabolizer' or 'ultra-rapid metabolizer.' While this type of terminology may promote patient recall with its simple, yet descriptive nature, it may be difficult for some patients to comprehend and/or cause adverse psychological or behavioral responses.

CONCLUSION

The language used to communicate results and their significance to patients will be important to consider in order to minimize confusion and potential psychological consequences such as increased anxiety that can adversely impact medication-taking behaviors.

PRACTICE IMPLICATIONS

Due to patients' unfamiliarity with PGx testing and the potential for confusion, adverse psychological effects, and decreased medication adherence, health providers need to be cognizant of the language used in discussing PGx test results with patients.

Opening Pandora’s box in the UK: a hypothetical pharmacogenetic test for clozapine

Clozapine is a uniquely efficacious antipsychotic drug in treatment-resistant schizophrenia. Its use is restricted due to adverse effects including a rare but dangerous reduction in neutrophils (agranulocytosis) and the mandatory hematological monitoring this entails in many countries. We review the statistical, ethical and legal issues arising from a hypothetical pharmacogenetic test for clozapine, using the UK as an exemplary case for consideration. Our key findings include: a consideration of the probabilistic results that a pharmacogenetic test may return; the impact on drug licensing; and the potential for pharmacogenetic tests for clozapine being used without consent under the UK’s legal framework. We make recommendations regarding regulatory changes applicable to the special case of pharmacogenetic testing in clozapine treatment.

The genetics of eating disorders

Over the past decade, considerable advances have been made in understanding genetic influences on eating pathology. Eating disorders aggregate in families, and twin studies reveal that additive genetic factors account for approximately 40% to 60% of liability to anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED). Molecular genetics studies have been undertaken to identify alterations in deoxyribonucleic acid sequence and/or gene expression that may be involved in the pathogenesis of disordered eating behaviors, symptoms, and related disorders and to uncover potential genetic variants that may contribute to variability of treatment response. This article provides an in-depth review of the scientific literature on the genetics of AN, BN, and BED including extant studies, emerging hypotheses, future directions, and clinical implications.

Strengths and weaknesses of pharmacogenetic studies of antipsychotic drugs: the potential value of the PEPs study

The successful application of pharmacogenetics in routine clinical practice is still a long way from becoming a reality. In order to favor the transfer of pharmacogenetic results to clinical practice, especially in psychiatry, these studies must be optimized. This article reviews the strengths and weaknesses that characterize pharmacogenetic studies in psychiatry and condition their implementation in clinical practice. We also include recommendations for improving the design of pharmacogenetic studies, which may convert their limitations into strengths and facilitate the implementation of their results into clinical practice. Finally, we discuss the potential value of naturalistic, prospective, multicenter and coordinated projects such as the 'Phenotype-genotype and environmental interaction. Application of a predictive model in first psychotic episodes' (known as the PEPs study, from the Spanish abbreviation) in pharmacogenetic studies.

Neurotrophic tyrosine kinase receptor type 2 (NTRK2) gene associated with treatment response to mood stabilizers in patients with bipolar I disorder

There is increasing evidence supporting the relationship between bipolar disorder (BP) and neurotrophin. The present study investigated the relationship between neurotrophic tyrosine kinase receptor type 2 (NTRK2) gene polymorphisms and bipolar I disorder (BP I) susceptibility and treatment response to mood stabilizers (lithium or valproate). Two-hundred eighty-four patients who met the DSM-IV criteria for BP I and 295 matched healthy controls were enrolled into this study. TaqMan® SNP genotyping assays were applied to genotype three NTRK2 gene polymorphisms (rs2769605, rs1565445, rs1387923). Our study showed a significant allelic association between NTRK2 gene polymorphism rs2769605 and treatment response to mood stabilizers in BP I patients (t = -2.53, P = 0.01). However, no significant association between NTRK2 gene polymorphisms and BP I susceptibility was observed after correcting for multiple comparisons. The results suggest that the NTRK2 gene polymorphism likely plays an essential role in treatment response to mood stabilizers in Han Chinese BP I patients.

Novel drug metabolism indices for pharmacogenetic functional status based on combinatory genotyping of CYP2C9, CYP2C19 and CYP2D6 genes

AIMS

We aim to demonstrate clinical relevance and utility of four novel drug-metabolism indices derived from a combinatory (multigene) approach to CYP2C9, CYP2C19 and CYP2D6 allele scoring. Each index considers all three genes as complementary components of a liver enzyme drug metabolism system and uniquely benchmarks innate hepatic drug metabolism reserve or alteration through CYP450 combinatory genotype scores.

METHODS

A total of 1199 psychiatric referrals were genotyped for polymorphisms in the CYP2C9, CYP2C19 and CYP2D6 gene loci and were scored on each of the four indices. The data were used to create distributions and rankings of innate drug metabolism capacity to which individuals can be compared. Drug-specific indices are a combination of the drug metabolism indices with substrate-specific coefficients.

RESULTS

The combinatory drug metabolism indices proved useful in positioning individuals relative to a population with regard to innate drug metabolism capacity prior to pharmacotherapy. Drug-specific indices generate pharmacogenetic guidance of immediate clinical relevance, and can be further modified to incorporate covariates in particular clinical cases.

CONCLUSIONS

We believe that this combinatory approach represents an improvement over the current gene-by-gene reporting by providing greater scope while still allowing for the resolution of a single-gene index when needed. This method will result in novel clinical and research applications, facilitating the translation from pharmacogenomics to personalized medicine, particularly in psychiatry where many drugs are metabolized or activated by multiple CYP450 isoenzymes.

Using a pharmacogenomic algorithm to guide the treatment of depression

The objective of this study was to evaluate the potential benefit of utilizing a pharmacogenomic testing report to guide the selection and dosing of psychotropic medications in an outpatient psychiatric practice. The non-randomized, open label, prospective cohort study was conducted from September 2009 to July 2010. In the first cohort, depressed patients were treated without the benefit of pharmacogenomic testing (the unguided group). A DNA sample was obtained from patients in the unguided group, but the results were not shared with either the physicians or patients until the end of the 8-week study period. In the second cohort (the guided group), testing results were provided at the beginning of the 8-week treatment period. Depression ratings were collected at baseline and after 2 weeks, 4 weeks and 8 weeks of treatment using the Quick Inventory of Depressive Symptomatology, Clinician Rated (QIDS-C16) and the 17-item Hamilton Rating Scale for Depression (HAM-D17). Clinician and patient satisfaction was also assessed. The reduction in depressive symptoms achieved within the guided treatment group was greater than the reduction of depressive symptoms in the unguided treatment group using either the QIDS-C16 (P=0.002) or HAM-D17 (P=0.04). We concluded that a rapidly available pharmacogenomic interpretive report provided clinical guidance that was associated with improved clinical outcomes for depressed patients treated in an outpatient psychiatric clinic setting.

Genome-wide pharmacogenomic study of neurocognition as an indicator of antipsychotic treatment response in schizophrenia

Neurocognitive deficits are a core feature of schizophrenia and, therefore, represent potentially critical outcome variables for assessing antipsychotic treatment response. We performed genome-wide association studies (GWAS) with 492K single nucleotide polymorphisms (SNPs) in a sample of 738 patients with schizophrenia from the Clinical Antipsychotic Trials of Intervention Effectiveness study. Outcome variables consisted of a neurocognitive battery administered at multiple time points over an 18-month period, measuring processing speed, verbal memory, vigilance, reasoning, and working memory domains. Genetic mediation of improvements in each of these five domains plus a composite neurocognitive measure was assessed for each of five antipsychotics (olanzapine, perphenazine, quetiapine, risperidone, and ziprasidone). Six SNPs achieved genome-wide significance using a pre-specified threshold that ensures, on average, only 1 in 10 findings is a false discovery. These six SNPs were located within, or in close proximity to, genes EHF, SLC26A9, DRD2, GPR137B, CHST8, and IL1A. The more robust findings, that is those significant across multiple neurocognitive domains and having adjacent SNPs showing evidence for association, were rs286913 at the EHF gene (p-value 6.99 × 10(-8), q-value 0.034, mediating the effects of ziprasidone on vigilance), rs11240594 at SLC26A9 (p-value 1.4 × 10(-7), q-value 0.068, mediating the effects of olanzapine on processing speed), and rs11677416 at IL1A (p-value 6.67 × 10(-7), q-value 0.081, mediating the effects of olanzapine on working memory). This study has generated several novel candidate genes for antipsychotic response. However, our findings will require replication and functional validation. To facilitate replication efforts, we provide all GWAS p-values for download.

Schizophrenia, "just the facts" 5. Treatment and prevention. Past, present, and future

The introduction of second-generation antipsychotics and cognitive therapies for schizophrenia over the past two decades generated considerable optimism about possibilities for recovery. To what extent have these developments resulted in better outcomes for affected individuals? What is the current state of our science and how might we address the many unmet needs in the prevention and treatment of schizophrenia? We trace the evolution of various treatments for schizophrenia and summarize current knowledge about available pharmacological and psychosocial treatments. We consider the widely prevalent efficacy-effectiveness gap in the application of available treatments and note the significant variability in individual treatment response and outcome. We outline an individualized treatment approach which emphasizes careful monitoring and collaborative decision-making in the context of ongoing benefit-risk assessment. We note that the evolution of both pharmacological and psychosocial treatments thus far has been based principally on serendipity and intuition. In view of our improved understanding of the etiology and pathophysiology of schizophrenia, there is an opportunity to develop prevention strategies and treatments based on this enhanced knowledge. In this context, we discuss potential psychopathological treatment targets and enumerate current pharmacological and psychosocial development efforts directed at them. Considering the stages of schizophrenic illness, we review approaches to prevent progression from the pre-symptomatic high-risk to the prodrome to the initial psychotic phase to chronicity. In view of the heterogeneity of risk factors, we summarize approaches towards targeted prevention. We evaluate the potential contribution of pharmacogenomics and other biological markers in optimizing individual treatment and outcome in the future.