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Arniotis-Streat S, Fonte A, Ziauddeen H. Psychotropic drugs, eating behaviour and weight gain. Curr Opin Psychiatry 2024; 37:331-336. [PMID: 38994802 DOI: 10.1097/yco.0000000000000953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 07/13/2024]
Abstract
PURPOSE OF REVIEW Psychotropic drug related weight gain is a common side-effect of significant concern to both clinicians and patients. Recent studies and treatment guidelines strongly support taking preventive and early treatment approaches to psychotropic drug-related weight gain (PDWG). Arguably the main pathway that PDWG occurs is via changes in eating behaviour leading to increased caloric intake. RECENT FINDINGS Systematic reviews and meta-analyses have provided good data on the nature and prevalence of alterations in eating behaviour with psychotropic treatment including increased hunger, night eating and binge eating. These changes are unsurprisingly more prominent with agents like olanzapine and clozapine that have high propensity to cause weight gain. SUMMARY Altered eating behaviour can serve as an earlier measure of the risk of weight gain and can be examined easily in clinical practice. Detecting these changes can enable earlier action in terms of switching treatments and starting pharmacological and nonpharmacological preventive strategies.
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Affiliation(s)
| | - Anthony Fonte
- Mental Health service, Fiona Stanley Fremantle Hospitals Group, Murdoch, WA, Australia
| | - Hisham Ziauddeen
- Mental Health service, Fiona Stanley Fremantle Hospitals Group, Murdoch, WA, Australia
- Dept of Psychiatry, University of Cambridge, Cambridge, UK
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Cha YJ, Chang IA, Jin EH, Song JH, Hong JH, Jung JG, Sunwoo J. Association between LEPR Genotype and Gut Microbiome in Healthy Non-Obese Korean Adults. Biomol Ther (Seoul) 2024; 32:146-153. [PMID: 37503756 PMCID: PMC10762272 DOI: 10.4062/biomolther.2023.116] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/11/2023] [Accepted: 07/12/2023] [Indexed: 07/29/2023] Open
Abstract
The LEPR (leptin receptor) genotype is associated with obesity. Gut microbiome composition differs between obese and non-obese adults. However, the impact of LEPR genotype on gut microbiome composition in humans has not yet been studied. In this study, the association between LEPR single nucleotide polymorphism (rs1173100, rs1137101, and rs790419) and the gut microbiome composition in 65 non-obese Korean adults was investigated. Leptin, triglyceride, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol levels were also measured in all participants. Mean ± SD (standard deviation) of age, body mass index, and leptin hormone levels of participants was 35.2 ± 8.1 years, 21.4 ± 1.8 kg/m2, and 7989.1 ± 6687.4 pg/mL, respectively. Gut microbiome analysis was performed at the phylum level by 16S rRNA sequencing. Among the 11 phyla detected, only one showed significantly different relative abundances between LEPR genotypes. The relative abundance of Candidatus Saccharibacteria was higher in the G/A genotype group than in the G/G genotype group for the rs1137101 single nucleotide polymorphism (p=0.0322). Participant characteristics, including body mass index, leptin levels, and other lipid levels, were similar between the rs1137101 G/G and G/A genotypes. In addition, the relative abundances of Fusobacteria and Tenericutes showed significant positive relationship with plasma leptin concentrations (p=0.0036 and p=0.0000, respectively). In conclusion, LEPR genotype and gut microbiome may be associated even in normal-weight Korean adults. However, further studies with a greater number of obese adults are needed to confirm whether LEPR genotype is related to gut microbiome composition.
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Affiliation(s)
- Yoon Jung Cha
- Clinical Trials Center, Chungnam National University Hospital, Daejeon 35015, Republic of Korea
- Department of Medical Science, Chungnam National University College of Medicine, Daejeon 35015, Republic of Korea
| | - In Ae Chang
- Clinical Trials Center, Chungnam National University Hospital, Daejeon 35015, Republic of Korea
| | - Eun-Heui Jin
- Translational Immunology Institute, Chungnam National University College of Medicine, Daejeon 35015, Republic of Korea
| | - Ji Hye Song
- Clinical Trials Center, Chungnam National University Hospital, Daejeon 35015, Republic of Korea
- Department of Medical Science, Chungnam National University College of Medicine, Daejeon 35015, Republic of Korea
| | - Jang Hee Hong
- Clinical Trials Center, Chungnam National University Hospital, Daejeon 35015, Republic of Korea
- Department of Pharmacology, Chungnam National University College of Medicine, Daejeon 35015, Republic of Korea
| | - Jin-Gyu Jung
- Department of Family Medicine, Chungnam National University Hospital, Daejeon 35015, Republic of Korea
| | - Jung Sunwoo
- Clinical Trials Center, Chungnam National University Hospital, Daejeon 35015, Republic of Korea
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Treatment-Resistant Schizophrenia, Clozapine Resistance, Genetic Associations, and Implications for Precision Psychiatry: A Scoping Review. Genes (Basel) 2023; 14:genes14030689. [PMID: 36980961 PMCID: PMC10048540 DOI: 10.3390/genes14030689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 03/03/2023] [Accepted: 03/08/2023] [Indexed: 03/14/2023] Open
Abstract
Treatment-resistant schizophrenia (TRS) is often associated with severe burden of disease, poor quality of life and functional impairment. Clozapine is the gold standard for the treatment of TRS, although it is also known to cause significant side effects in some patients. In view of the burgeoning interest in the role of genetic factors in precision psychiatry, we conducted a scoping review to narratively summarize the current genetic factors associated with TRS, clozapine resistance and side effects to clozapine treatment. We searched PubMed from inception to December 2022 and included 104 relevant studies in this review. Extant evidence comprised associations between TRS and clozapine resistance with genetic factors related to mainly dopaminergic and serotoninergic neurotransmitter systems, specifically, TRS and rs4680, rs4818 within COMT, and rs1799978 within DRD2; clozapine resistance and DRD3 polymorphisms, CYP1A2 polymorphisms; weight gain with LEP and SNAP-25 genes; and agranulocytosis risk with HLA-related polymorphisms. Future studies, including replication in larger multi-site samples, are still needed to elucidate putative risk genes and the interactions between different genes and their correlations with relevant clinical factors such as psychopathology, psychosocial functioning, cognition and progressive changes with treatment over time in TRS and clozapine resistance.
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Singh S, Ricardo-Silgado ML, Bielinski SJ, Acosta A. Pharmacogenomics of Medication-Induced Weight Gain and Antiobesity Medications. Obesity (Silver Spring) 2021; 29:265-273. [PMID: 33491309 PMCID: PMC8215694 DOI: 10.1002/oby.23068] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 09/03/2020] [Accepted: 09/29/2020] [Indexed: 12/20/2022]
Abstract
Obesity is a chronic, multifactorial disease associated with a large number of comorbidities. The clinical management of obesity involves a stepwise integrated approach, beginning with behavioral and lifestyle modification, followed by antiobesity medications, endobariatric procedures, and bariatric surgery. Weight gain and subsequent obesity are common side effects of medications, such as prednisone or antipsychotics. In this era of precision medicine, it is essential to identify patients at the highest risk of weight gain as a result of medication use. Pharmacogenomics could play an important role in obesity management by optimizing use of antiobesity medications as well as minimizing adverse weight gain. This review aims to provide a comprehensive analysis of the current literature on the role of pharmacogenomics in obesity and medication-induced weight gain. In summary, there are more robust studies of medication associated with weight gain and pharmacogenomics, and more studies are needed to understand the role of pharmacogenomics in antiobesity medications.
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Affiliation(s)
- Sneha Singh
- Precision Medicine for Obesity Program, Clinical Enteric Neuroscience Translational and Epidemiological Research (C.E.N.T.E.R.), and Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN
| | - Maria L Ricardo-Silgado
- Precision Medicine for Obesity Program, Clinical Enteric Neuroscience Translational and Epidemiological Research (C.E.N.T.E.R.), and Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN
| | | | - Andres Acosta
- Precision Medicine for Obesity Program, Clinical Enteric Neuroscience Translational and Epidemiological Research (C.E.N.T.E.R.), and Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN
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Yoshida K, Maciukiewicz M, Zai CC, Gonçalves VF, Brandl EJ, Lieberman JA, Meltzer HY, Tiwari AK, Kennedy JL, Müller DJ. Association between the -2548G/A polymorphism of the leptin gene and antipsychotic-induced weight gain: Analysis of the CATIE sample and meta-analysis. Prog Neuropsychopharmacol Biol Psychiatry 2020; 102:109952. [PMID: 32335267 DOI: 10.1016/j.pnpbp.2020.109952] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 04/21/2020] [Accepted: 04/22/2020] [Indexed: 11/25/2022]
Abstract
BACKGROUND Antipsychotics, especially most of the second-generation antipsychotics, have a high risk for metabolic syndrome and antipsychotic-induced weight gain (AIWG). A promoter variant of the leptin (LEP) gene, -2548G/A (rs7799039), has been associated with AIWG in several studies. The aim of this study was to evaluate this association in the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) sample, followed by meta-analysis. METHODS We investigated the association between rs7799039 and AIWG in a sub-sample of European (N = 164) individuals from the CATIE study. Body mass index (BMI) change and weight gain (presence or absence) was analyzed using ANCOVA and logistic regression, respectively. For the meta-analysis, a literature search was conducted using MEDLINE, Embase, and PsycINFO up to October 2019. The pooled odds ratio was calculated for presence or absence of weight gain (≥7% weight change) using a random effects model. RESULTS We did not detect an association between rs7799039 and BMI change or weight gain (presence or absence) in the CATIE sample. As for the meta-analysis, we included 12 studies. No significant associations between the LEP rs7799039 polymorphism and AIWG were observed under the allelic genetic model (allele A vs. allele G) (OR = 1.10 [0.71, 1.70], p = .68). In the subgroup analyses of first-episode schizophrenia patients, a significant association between the A-allele and weight gain was observed, respectively (OR = 2.32 [1.41, 3.82], p = .0009). CONCLUSIONS The present meta-analysis showed no significant effect of rs7799039 on AIWG. However, this variant may influence AIWG in first-episode schizophrenia patients. Further investigation of a larger and more homogenous sample is required to elucidate the role of the LEP gene in AIWG.
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Affiliation(s)
- Kazunari Yoshida
- Pharmacogenetics Research Clinic, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada; Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | - Malgorzata Maciukiewicz
- Pharmacogenetics Research Clinic, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada; Department of Rheumatology, Center of Experimental Rheumatology, University Hospital of Zurich, Zurich, Switzerland
| | - Clement C Zai
- Pharmacogenetics Research Clinic, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada; Institute of Medical Science, University of Toronto, Toronto, ON, Canada; Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Vanessa F Gonçalves
- Pharmacogenetics Research Clinic, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Eva J Brandl
- Department of Psychiatry and Psychotherapy, Campus Mitte, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Jeffrey A Lieberman
- Department of Psychiatry, College of Physicians and Surgeons, Columbia University, The New York State Psychiatric Institute, New York City, NY, USA
| | - Herbert Y Meltzer
- Department of Psychiatry and Behavioral Sciences, Northwestern Feinberg School of Medicine, Evanston, IL, USA
| | - Arun K Tiwari
- Pharmacogenetics Research Clinic, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - James L Kennedy
- Pharmacogenetics Research Clinic, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada; Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Daniel J Müller
- Pharmacogenetics Research Clinic, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada; Institute of Medical Science, University of Toronto, Toronto, ON, Canada.
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Chen Y, Wang Y, Fang X, Zhang Y, Song L, Zhang C. Association of the HTR2C-759C/T polymorphism and antipsychotic-induced weight gain: a meta-analysis. Gen Psychiatr 2020; 33:e100192. [PMID: 32478286 PMCID: PMC7232784 DOI: 10.1136/gpsych-2020-100192] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 04/04/2020] [Indexed: 11/27/2022] Open
Abstract
Background Antipsychotic-induced weight gain (AIWG) is a crucial factor for the medication cessation of patients with schizophrenia. Multiple studies have shown that the functional polymorphism -759 C/T (rs3813929) in the HTR2C promoter region could possibly be correlated with AIWG. Aim To evaluate the genetic association of the HTR2C-759C/T polymorphism and AIWG in patients with schizophrenia with antipsychotic drugs (APDs) administration. Methods Eligible studies were identified by searching the following databases: PubMed, Embase, Web of Science, China Nation Knowledge Infrastructure (CNKI), VIP, Wanfang Data, Chinese Biomedical Literature Database (CBM) and the Airiti Library. The quality of studies was evaluated based on the Newcastle-Ottawa Scale. The pooled OR and 95% CI were calculated for the dominant (CT/TT/T vs CC/C) mode, and subgroup analyses were performed based on ethnicity, antipsychotic medication and gender; all statistical analyses were performed using the statistical software STATA V.12.0. Result A total of 17 studies with 3170 patients with schizophrenia were included in our meta-analysis. The result of the meta-analysis has shown that the association between the -759 C/T polymorphism and AIWG is statistically significant (OR 0.34, 95% CI: 0.20 to 0.57, z=4.11, p<0.001). The subgroup analyses revealed significant correlations between the -759 C/T polymorphism and AIWG in the Caucasian population (OR 0.33, 95% CI: 0.14 to 0.77, z=2.55, p=0.011), the Asian population (OR 0.31, 95% CI: 0.18 to 0.52, z=4.46, p<0.001), the patients with APDs administration (CT/TT/T vs CC/C: OR 0.63, 95% CI: 0.40 to 1.00, z=1.97, p=0.049) and the patients with atypical antipsychotic drug administration (CT/TT/T vs CC/C: OR 0.21, 95% CI: 0.09 to 0.47, z=3.83, p<0.001). The sensitivity analysis showed that the results were stable. Begg’s test (after correction z=1.07, p=0.287) and Egger’s test (t=−2.41, p=0.029) show that the included articles have no significant publication bias. Conclusion There is a significant genetic association between HTR2C-759C/T and AIWG, and patients with T allele are less likely to have AIWG.
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Affiliation(s)
- Yan Chen
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine Affiliated Shanghai Mental Health Center, Shanghai, China
| | - Yewei Wang
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine Affiliated Shanghai Mental Health Center, Shanghai, China
| | - Xinyu Fang
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine Affiliated Shanghai Mental Health Center, Shanghai, China
| | - Yi Zhang
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine Affiliated Shanghai Mental Health Center, Shanghai, China
| | - Lisheng Song
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine Affiliated Shanghai Mental Health Center, Shanghai, China
| | - Chen Zhang
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine Affiliated Shanghai Mental Health Center, Shanghai, China
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Molecular pathway analysis associates alterations in obesity-related genes and antipsychotic-induced weight gain. Acta Neuropsychiatr 2020; 32:72-83. [PMID: 31619305 DOI: 10.1017/neu.2019.41] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Antipsychotics often induce excessive weight gain. We hypothesised that individuals with genetic variations related to known obesity-risk genes have an increased risk of excessive antipsychotic-induced weight gain (AIWG). This hypothesis was tested in a subset of the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) trial data set. METHODS The CATIE trial compared effects and side effects of five different antipsychotics through an 18-month period. Based on the maximum weight gain recorded, excessive weight gain was defined as >7% weight gain. Cytoscape and GeneMANIA were instrumental in composing a molecular pathway from eight selected genes linked to obesity. Genetic information on a total of 495.172 single-nucleotide polymorphisms (SNPs) were available from 765 (556 males) individuals. Enrichment test was conducted through ReactomePA and Bioconductor. A permutation test was performed, testing the generated pathway against 105 permutated pathways (p ≤ 0.05). In addition, a standard genome-wide association study (GWAS) analysis was performed. RESULT GWAS analysis did not detect significant differences related to excessive weight gain. The pathway generated contained 28 genes. A total of 2067 SNPs were significantly expressed (p < 0.01) within this pathway when comparing excessive weight gainers to the rest of the sample. Affected genes including PPARG and PCSK1 were not previously related to treatment-induced weight gain. CONCLUSIONS The molecular pathway composed from high-risk obesity genes was shown to overlap with genetics of patients who gained >7% weight gain during the CATIE trial. This suggests that genes related to obesity compose a pathway of increased risk of excessive AIWG. Further independent analyses are warranted that may confirm or clarify the possible reasoning behind.
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Maciukiewicz M, Tiwari AK, Zai CC, Gorbovskaya I, Laughlin CP, Nurmi EL, Liebermann JA, Meltzer HY, Kennedy JL, Müller DJ. Genome-wide association study on antipsychotic-induced weight gain in Europeans and African-Americans. Schizophr Res 2019; 212:204-212. [PMID: 31447353 DOI: 10.1016/j.schres.2019.07.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Revised: 06/13/2019] [Accepted: 07/11/2019] [Indexed: 01/07/2023]
Abstract
BACKGROUND Antipsychotic (AP) medications are the first line of treatment for schizophrenia. However, most conferr a risk of antipsychotic-induced weight gain (AIWG). The objective of this investigation was to conduct a genome-wide association study (GWAS) of AIWG, followed by comprehensive, post-GWAS approaches. METHODS We investigated n = 201 schizophrenia or schizoaffective disorder patients of European and African American ancestry who were treated primarily with clozapine or olanzapine. We conducted a genome-wide association analysis for AIWG, defined primarily as a percentage of weight change from baseline. RESULTS When examining Europeans (n = 147), we noticed an association between rs62097526 (β = 0.39, p = 3.59 × 10-6, CADD = 2.213) variant, located downstream of the CIDEA gene, which is considered a risk factor for AIWG. In the entire sample, we observed a significant association between rs1525085 (β = 0.411, p = 3.15 × 10-9) variant of the DGKB gene and AIWG. The association was nominally significant in Europeans (β = 0.271, p = 0.002) and African Americans (β = 0.579, p = 5.73 × 10-5) with the same risk allele. Our top genes (p < 5 × 10-5) were enriched in the GWAS catalog for the risk of obesity and interacted with the known risk factors for obesity (G6PD) and diabetes (IRS1). In addition, these genes are targeted by miRNAs related to schizophrenia (mir-34a) and obesity (mir-19b). However, our polygenic risk score analyses did not provide support for major genetic overlap between obesity and the risk of AIWG. CONCLUSIONS In summary, we propose that the CIDEA and DGKB genes are risk factors for AIWG in transethnic populations. Additionally, our evidence suggests that the G6PD and IRS1 gene-related pathways might be involved in AIWG.
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Affiliation(s)
- Malgorzata Maciukiewicz
- Pharmacogenetic Research Clinic, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Arun K Tiwari
- Pharmacogenetic Research Clinic, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Clement C Zai
- Pharmacogenetic Research Clinic, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Ilona Gorbovskaya
- Pharmacogenetic Research Clinic, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Christopher P Laughlin
- Division of Child and Adolescent Psychiatry, UCLA Semel Institute for Neuroscience, Los Angeles, California, USA
| | - Erika L Nurmi
- Division of Child and Adolescent Psychiatry, UCLA Semel Institute for Neuroscience, Los Angeles, California, USA
| | - Jeffrey A Liebermann
- Department of Psychiatry, College of Physicians & Surgeons, Columbia University, New York, NY, USA
| | - Herbert Y Meltzer
- Department of Psychiatry and Behavioral Sciences, Northwestern University, Chicago, IL, USA
| | - James L Kennedy
- Pharmacogenetic Research Clinic, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada; Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Daniel J Müller
- Pharmacogenetic Research Clinic, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada; Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
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Puangpetch A, Srisawasdi P, Unaharassamee W, Jiratjintana N, Vanavanan S, Punprasit S, Na Nakorn C, Sukasem C, Kroll MH. Association between polymorphisms of LEP, LEPR, DRD2, HTR2A and HTR2C genes and risperidone- or clozapine-induced hyperglycemia. PHARMACOGENOMICS & PERSONALIZED MEDICINE 2019; 12:155-166. [PMID: 31496784 PMCID: PMC6689662 DOI: 10.2147/pgpm.s210770] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 07/16/2019] [Indexed: 12/17/2022]
Abstract
Objective To determine whether genetic polymorphisms related to pharmacodynamics with metabolic adverse effects, namely leptin promoter (LEP) rs7799039, leptin receptor rs1137101, dopamine D2 rs4436578, serotonin 5-HT2A rs6313, and serotonin 5-HT2C rs518147 and rs12836771, are associated with hyperglycemia induced by risperidone or clozapine in adult Thai patients with psychosis. Methods A total of 180 patients treated with risperidone-based (n=130) or clozapine-based (n=50) regimens were included in this study. Blood samples were analyzed for genotyping of the candidate genes and biochemical testing. Genotyping was performed by conducting a TaqMan real-time polymerase chain reaction-based analysis. Results The prevalence of hyperglycemia was higher in patients receiving clozapine (64.0%) than in those receiving risperidone (30.8%). Among the candidate genes, only the LEP rs7799039 polymorphism demonstrated a significant association with hyperglycemia (χ2=9.879, P=0.008) in patients treated with risperidone; patients with the AA genotype had the highest risk (41.1%), followed by those with AG (20.8%) and GG (0%) genotypes. Using the recessive genetic model (AA vs AG + GG), the odds ratio and 95% CI were 3.28 and 1.44 −7.50, respectively. None of the genes were associated with hyperglycemia in patients treated with clozapine. A binary logistic regression revealed that the LEP rs7799039 polymorphism demonstrated a significant association with hyperglycemia, independent of body-mass index (BMI) in patients receiving risperidone; the odds ratio (95% CI) was 3.188 (1.399–7.262), P=0.006. By contrast, none of the pharmacodynamic genetic factors, except for BMI, were significantly associated with hyperglycemia in patients receiving clozapine. Conclusion The risk of type 2 diabetes mellitus is associated with the LEP rs7799039 polymorphism in Thai adults receiving risperidone but not in those receiving clozapine. Clarifying underlying mechanisms and risk of hyperglycemia provides an opportunity to prevent impaired glucose metabolism in patients receiving risperidone or clozapine.
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Affiliation(s)
- Apichaya Puangpetch
- Division of Pharmacogenomics and Personalized Medicine, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Pornpen Srisawasdi
- Division of Clinical Chemistry, Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | | | - Napa Jiratjintana
- Department of Psychiatry, Somdet Chaopraya Institute of Psychiatry, Bangkok, Thailand
| | - Somlak Vanavanan
- Division of Clinical Chemistry, Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Suweejuk Punprasit
- Division of Clinical Chemistry, Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Chalitpon Na Nakorn
- Division of Pharmacogenomics and Personalized Medicine, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Chonlaphat Sukasem
- Division of Pharmacogenomics and Personalized Medicine, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
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Pharmacogenetic Correlates of Antipsychotic-Induced Weight Gain in the Chinese Population. Neurosci Bull 2019; 35:561-580. [PMID: 30607769 DOI: 10.1007/s12264-018-0323-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 09/15/2018] [Indexed: 12/11/2022] Open
Abstract
Antipsychotic-induced weight gain (AIWG) is a common adverse effect of this treatment, particularly with second-generation antipsychotics, and it is a major health problem around the world. We aimed to review the progress of pharmacogenetic studies on AIWG in the Chinese population to compare the results for Chinese with other ethnic populations, identify the limitations and problems of current studies, and provide future research directions in China. Both English and Chinese electronic databases were searched to identify eligible studies. We determined that > 25 single-nucleotide polymorphisms in 19 genes have been investigated in association with AIWG in Chinese patients over the past few decades. HTR2C rs3813929 is the most frequently studied single-nucleotide polymorphism, and it seems to be the most strongly associated with AIWG in the Chinese population. However, many genes that have been reported to be associated with AIWG in other ethnic populations have not been included in Chinese studies. To explain the pharmacogenetic reasons for AIWG in the Chinese population, genome-wide association studies and multiple-center, standard, unified, and large samples are needed.
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Genetic validation study of protein tyrosine phosphatase receptor type D (PTPRD) gene variants and risk for antipsychotic-induced weight gain. J Neural Transm (Vienna) 2018; 126:27-33. [DOI: 10.1007/s00702-018-1921-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 08/27/2018] [Indexed: 01/08/2023]
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Abstract
PURPOSE OF REVIEW This review highlights recent advances in the investigation of genetic factors for antipsychotic response and side effects. RECENT FINDINGS Antipsychotics prescribed to treat psychotic symptoms are variable in efficacy and propensity for causing side effects. The major side effects include tardive dyskinesia, antipsychotic-induced weight gain (AIWG), and clozapine-induced agranulocytosis (CIA). Several promising associations of polymorphisms in genes including HSPG2, CNR1, and DPP6 with tardive dyskinesia have been reported. In particular, a functional genetic polymorphism in SLC18A2, which is a target of recently approved tardive dyskinesia medication valbenazine, was associated with tardive dyskinesia. Similarly, several consistent findings primarily from genes modulating energy homeostasis have also been reported (e.g. MC4R, HTR2C). CIA has been consistently associated with polymorphisms in the HLA genes (HLA-DQB1 and HLA-B). The association findings between glutamate system genes and antipsychotic response require additional replications. SUMMARY The findings to date are promising and provide us a better understanding of the development of side effects and response to antipsychotics. However, more comprehensive investigations in large, well characterized samples will bring us closer to clinically actionable findings.
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Unresolved Issues for Utilization of Atypical Antipsychotics in Schizophrenia: Antipsychotic Polypharmacy and Metabolic Syndrome. Int J Mol Sci 2017; 18:ijms18102174. [PMID: 29057817 PMCID: PMC5666855 DOI: 10.3390/ijms18102174] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 10/11/2017] [Accepted: 10/14/2017] [Indexed: 12/13/2022] Open
Abstract
Atypical antipsychotics (AAP) are the prevailing form of schizophrenia treatment today due to their low side effects and superior efficacy. Nevertheless, some issues still need to be addressed. First, there are still a large number of patients with treatment-resistant schizophrenia (TRS), which has led to a growing trend to resort to AAP polypharmacy with few side effects. Most clinical treatment guidelines recommend clozapine monotherapy in TRS, but around one third of schizophrenic patients fail to respond to clozapine. For these patients, with clozapine-resistant schizophrenia AAP polypharmacy is a common strategy with a continually growing evidence base. Second, AAP generally have great risks for developing metabolic syndrome, such as weight gain, abnormality in glucose, and lipid metabolism. These metabolic side effects have become huge stumbling blocks in today's schizophrenia treatment that aims to improve patients' quality of life as well as symptoms. The exact reasons why this particular syndrome occurs in patients treated with AAP is as yet unclear though factors such as interaction of AAP with neurotransmitter receptors, genetic pholymorphisms, type of AAPs, length of AAP use, and life style of schizophrenic patients that may contribute to its development. The present article aimed to review the evidence underlying these key issues and provide the most reasonable interpretations to expand the overall scope of antipsychotics usage.
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Genetic variants impacting metabolic outcomes among people on clozapine: a systematic review and meta-analysis. Psychopharmacology (Berl) 2017; 234:2989-3008. [PMID: 28879574 DOI: 10.1007/s00213-017-4728-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 08/23/2017] [Indexed: 12/11/2022]
Abstract
Clozapine is the gold standard medication for treatment refractory schizophrenia, but unfortunately, its use is also associated with many adverse metabolic side effects. There may be a strong genetic component to the development of these adverse effects. We undertook a systematic review to examine the evidence for genetic variation being associated with secondary metabolic outcomes in patients with schizophrenia on clozapine, under both longitudinal and cross-sectional study designs. We limited studies to those examining patients definitely taking clozapine, unlike prior reviews that have examined metabolic effects of patients taking a range of antipsychotic medications. We found associations with outcomes such as increases in BMI and metabolic syndrome for variants in genes such as LEP and HTR2C. Meta-analysis of rs381328 in HTR2C revealed that the presence of the T allele led to a 0.63 kg/m2 (95% CI - 1.06 to - 0.19; p = 0.005) decrease in BMI compared to the C allele. Study and population heterogeneity and lack of statistical power among reviewed articles mean that evidence is lacking to warrant prophylactic genotyping of patients commencing clozapine to predict those at increased risk of developing adverse metabolic effects. Further efforts to establish collaborative consortia, consensus around study design and replication studies in independent populations should be encouraged.
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Lally J, Gaughran F, Timms P, Curran SR. Treatment-resistant schizophrenia: current insights on the pharmacogenomics of antipsychotics. Pharmgenomics Pers Med 2016; 9:117-129. [PMID: 27853387 PMCID: PMC5106233 DOI: 10.2147/pgpm.s115741] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Up to 30% of people with schizophrenia do not respond to two (or more) trials of dopaminergic antipsychotics. They are said to have treatment-resistant schizophrenia (TRS). Clozapine is still the only effective treatment for TRS, although it is underused in clinical practice. Initial use is delayed, it can be hard for patients to tolerate, and clinicians can be uncertain as to when to use it. What if, at the start of treatment, we could identify those patients likely to respond to clozapine - and those likely to suffer adverse effects? It is likely that clinicians would feel less inhibited about using it, allowing clozapine to be used earlier and more appropriately. Genetic testing holds out the tantalizing possibility of being able to do just this, and hence the vital importance of pharmacogenomic studies. These can potentially identify genetic markers for both tolerance of and vulnerability to clozapine. We aim to summarize progress so far, possible clinical applications, limitations to the evidence, and problems in applying these findings to the management of TRS. Pharmacogenomic studies of clozapine response and tolerability have produced conflicting results. These are due, at least in part, to significant differences in the patient groups studied. The use of clinical pharmacogenomic testing - to personalize clozapine treatment and identify patients at high risk of treatment failure or of adverse events - has moved closer over the last 20 years. However, to develop such testing that could be used clinically will require larger, multicenter, prospective studies.
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Affiliation(s)
- John Lally
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
- Department of Psychiatry, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, Ireland
- National Psychosis Service
| | - Fiona Gaughran
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
- National Psychosis Service
| | - Philip Timms
- START Team, South London and Maudsley NHS Foundation Trust
- King’s College London
| | - Sarah R Curran
- King’s College London
- South West London and St George’s Mental Health NHS Foundation Trust
- St George’s University of London, London, UK
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Osman M, Devadas V. Clozapine-induced dysphagia with secondary substantial weight loss. BMJ Case Rep 2016; 2016:bcr-2016-216445. [PMID: 27543610 DOI: 10.1136/bcr-2016-216445] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Dysphagia is listed as a 'rare' side effect following clozapine treatment. In this case report, we describe how significant clozapine-induced dysphagia has led to significant reduction of nutritional intake with subsequent substantial weight loss. An 18-year-old single man with an established diagnosis of treatment-resistant paranoid schizophrenia recovered well on a therapeutic dose of clozapine. However, he was noted to lose weight significantly (up to 20% of his original weight) as the dose was uptitrated. This was brought about by development of dysphagia, likely to be due to clozapine. Addition of nutritional supplementary liquids and initiation of a modified behavioural dietary/swallowing programme, while repeatedly mastering the Mendelsohn manoeuvre technique, alleviated the swallowing difficulties and restored his weight.
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Affiliation(s)
- Mugtaba Osman
- Department of Psychiatry, Letterkenny General Hospital, Letterkenny, Ireland
| | - Vekneswaran Devadas
- Department of Psychiatry, Letterkenny General Hospital, Letterkenny, Ireland
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MacNeil RR, Müller DJ. Genetics of Common Antipsychotic-Induced Adverse Effects. MOLECULAR NEUROPSYCHIATRY 2016; 2:61-78. [PMID: 27606321 DOI: 10.1159/000445802] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 03/24/2016] [Indexed: 12/12/2022]
Abstract
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.
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Affiliation(s)
- Raymond R MacNeil
- Mood Research Laboratory, Department of Psychology, Queen's University, Kingston, Ont., Canada
| | - Daniel J Müller
- Departments of Psychiatry, University of Toronto, Toronto, Ont., Canada; Departments of Pharmacology and Toxicology, University of Toronto, Toronto, Ont., Canada; Pharmacogenetics Research Clinic, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ont., Canada
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Montastruc F, Palmaro A, Bagheri H, Schmitt L, Montastruc JL, Lapeyre-Mestre M. Role of serotonin 5-HT2C and histamine H1 receptors in antipsychotic-induced diabetes: A pharmacoepidemiological-pharmacodynamic study in VigiBase. Eur Neuropsychopharmacol 2015; 25:1556-65. [PMID: 26256010 DOI: 10.1016/j.euroneuro.2015.07.010] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 06/23/2015] [Accepted: 07/14/2015] [Indexed: 02/06/2023]
Abstract
Pharmacodynamic mechanisms of diabetes induced by antipsychotic drugs remain unclear, while numerous receptors have been suspected to be involved in the genesis of this Adverse Drug Reaction (ADR). We investigated potential relationships between antipsychotics׳ receptor occupancy (serotonin 5-HT1A, 5-HT2A, 5-HT2C, histamine H1, muscarinic M3, adrenergic α1, α2 or dopaminergic D2 D3 occupancies) and reports of diabetes using VigiBase(®), the World Health Organization (WHO) global Individual Case Safety Report (ICSR) database. All ADR reports from 15 first and second generation antipsychotic drugs recorded in VigiBase(®) were extracted. Logistic regression models, completed by disproportionality analysis, were used to determine the associations between antipsychotics׳ receptor occupancy and ICSRs of diabetes on VigiBase(®). During the study period, 94,460 ICSRs involved at least one of the 15 antipsychotics of interest. Diabetes was reported in 1799 (1.9%) patients. Clozapine was the most frequently suspected drug (n=953; 53.0%). A significant and positive association was found between histamine H1, muscarinic M3 and serotonin 5-HT2C, 5-HT2A receptor occupancies and reports of diabetes. A multivariable stepwise regression model showed that only serotonin 5-HT2c (AOR=2.13, CI 95% 1.72-2.64) and histamine H1 (AOR=1.91, CI 95% 1.38-2.64) predicted the risk for diabetes mellitus (p<0.001). Using an original pharmacoepidemiology-pharmacodynamic (PE-PD) approach, our study supports that antipsychotic drugs blocking simultaneously histamine H1 and serotonin 5-HT2C receptors are more frequently associated with diabetes reports in VigiBase(®) than other antipsychotics. These findings should encourage investigation of histamine H1 and serotonin 5-HT2C properties for predicting the risk of glycemic effects in candidate antipsychotics.
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Affiliation(s)
- François Montastruc
- Service de Pharmacologie Médicale et Clinique, Faculté de Médecine de Toulouse, Centre Hospitalier Universitaire de Toulouse, France; INSERM UMR 1027, Pharmacoépidémiologie, Evaluation de l׳utilisation et du risque médicamenteux, Université de Toulouse, France; Pharmacopôle Midi-Pyrénées, Centre Midi-Pyrénées de Pharmacovigilance, de Pharmacoépidémiologie et d׳Informations sur le médicament, Toulouse, France; Inserm CIC 1436 Toulouse, CIC de Toulouse, Toulouse University Hospital, Place du Dr Baylac, 31059 Toulouse Cedex 9, France.
| | - Aurore Palmaro
- Service de Pharmacologie Médicale et Clinique, Faculté de Médecine de Toulouse, Centre Hospitalier Universitaire de Toulouse, France; INSERM UMR 1027, Pharmacoépidémiologie, Evaluation de l׳utilisation et du risque médicamenteux, Université de Toulouse, France; Inserm CIC 1436 Toulouse, CIC de Toulouse, Toulouse University Hospital, Place du Dr Baylac, 31059 Toulouse Cedex 9, France
| | - Haleh Bagheri
- Service de Pharmacologie Médicale et Clinique, Faculté de Médecine de Toulouse, Centre Hospitalier Universitaire de Toulouse, France; INSERM UMR 1027, Pharmacoépidémiologie, Evaluation de l׳utilisation et du risque médicamenteux, Université de Toulouse, France; Pharmacopôle Midi-Pyrénées, Centre Midi-Pyrénées de Pharmacovigilance, de Pharmacoépidémiologie et d׳Informations sur le médicament, Toulouse, France; Inserm CIC 1436 Toulouse, CIC de Toulouse, Toulouse University Hospital, Place du Dr Baylac, 31059 Toulouse Cedex 9, France
| | - Laurent Schmitt
- Service Hospitalo-Universitaire de Psychiatrie et Psychologie Médicale, Faculté de Médecine de Toulouse, Centre Hospitalier Universitaire de Toulouse, France
| | - Jean-Louis Montastruc
- Service de Pharmacologie Médicale et Clinique, Faculté de Médecine de Toulouse, Centre Hospitalier Universitaire de Toulouse, France; INSERM UMR 1027, Pharmacoépidémiologie, Evaluation de l׳utilisation et du risque médicamenteux, Université de Toulouse, France; Pharmacopôle Midi-Pyrénées, Centre Midi-Pyrénées de Pharmacovigilance, de Pharmacoépidémiologie et d׳Informations sur le médicament, Toulouse, France; Inserm CIC 1436 Toulouse, CIC de Toulouse, Toulouse University Hospital, Place du Dr Baylac, 31059 Toulouse Cedex 9, France
| | - Maryse Lapeyre-Mestre
- Service de Pharmacologie Médicale et Clinique, Faculté de Médecine de Toulouse, Centre Hospitalier Universitaire de Toulouse, France; INSERM UMR 1027, Pharmacoépidémiologie, Evaluation de l׳utilisation et du risque médicamenteux, Université de Toulouse, France; Inserm CIC 1436 Toulouse, CIC de Toulouse, Toulouse University Hospital, Place du Dr Baylac, 31059 Toulouse Cedex 9, France
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Sriretnakumar V, Huang E, Müller DJ. Pharmacogenetics of clozapine treatment response and side-effects in schizophrenia: an update. Expert Opin Drug Metab Toxicol 2015; 11:1709-31. [PMID: 26364648 DOI: 10.1517/17425255.2015.1075003] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
INTRODUCTION Clozapine (CLZ) is the most effective treatment for treatment-resistant schizophrenia (SCZ) patients, with potential added benefits of reduction in suicide risk and aggression. However, CLZ is also mainly underused due to its high risk for the potentially lethal side-effect of agranulocytosis as well as weight gain and related metabolic dysregulation. Pharmacogenetics promises to enable the prediction of patient treatment response and risk of adverse effects based on patients' genetics, paving the way toward individualized treatment. AREA COVERED This article reviews pharmacogenetics studies of CLZ response and side-effects with a focus on articles from January 2012 to February 2015, as an update to the previous reviews. Pharmacokinetic genes explored primarily include CYP1A2, while pharmacodynamic genes consisted of traditional pharmacogenetic targets such as brain-derived neurotrophic factor as well novel mitochondrial genes, NDUFS-1 and translocator protein. EXPERT OPINION Pharmacogenetics is a promising avenue for individualized medication of CLZ in SCZ, with several consistently replicated gene variants predicting CLZ response and side-effects. However, a large proportion of studies have yielded mixed results. Large-scale Genome-wide association studies (e.g., CRESTAR) and targeted gene studies with standardized designs (response measurements, treatment durations, plasma level monitoring) are required for further progress toward clinical translation. Additionally, in order to improve study quality, we recommend accounting for important confounders, including polypharmacy, baseline measurements, treatment duration, gender, and age at onset.
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Affiliation(s)
- Venuja Sriretnakumar
- a 1 Campbell Family Research Institute, Pharmacogenetics Research Clinic, Centre for Addiction and Mental Health , Toronto, Ontario, Canada +1 416 535 8501 ; +1 416 979 4666 ; .,b 2 University of Toronto, Department of Laboratory Medicine and Pathobiology , Ontario, Canada
| | - Eric Huang
- a 1 Campbell Family Research Institute, Pharmacogenetics Research Clinic, Centre for Addiction and Mental Health , Toronto, Ontario, Canada +1 416 535 8501 ; +1 416 979 4666 ; .,c 3 University of Toronto, Institute of Medical Sciences , Ontario, Canada
| | - Daniel J Müller
- a 1 Campbell Family Research Institute, Pharmacogenetics Research Clinic, Centre for Addiction and Mental Health , Toronto, Ontario, Canada +1 416 535 8501 ; +1 416 979 4666 ; .,c 3 University of Toronto, Institute of Medical Sciences , Ontario, Canada.,d 4 University of Toronto, Department of Psychiatry , Ontario, Canada
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