Schizophrenia is a debilitating psychiatric condition often associated with poor quality of life and decreased life expectancy. Lack of progress in improving treatment outcomes has been attributed to limited knowledge of the underlying biology, although large-scale genomic studies have begun to provide insights. We report a new genome-wide association study of schizophrenia (11,260 cases and 24,542 controls), and through meta-analysis with existing data we identify 50 novel associated loci and 145 loci in total. Through integrating genomic fine-mapping with brain expression and chromosome conformation data, we identify candidate causal genes within 33 loci. We also show for the first time that the common variant association signal is highly enriched among genes that are under strong selective pressures. These findings provide new insights into the biology and genetic architecture of schizophrenia, highlight the importance of mutation-intolerant genes and suggest a mechanism by which common risk variants persist in the population.

Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Heritability and polygenic predictionIn the EUR sample, the SNP-based heritability (h 2 SNP ) (that is, the proportion of variance in liability attributable to all measured SNPs)

Recently, a novel allelic variant of cytochrome P450 2C19 encoding ultrarapid enzyme activity was described (denoted CYP2C19*17). The objective of this study was to evaluate the impact of CYP2C19*17 on serum concentration of escitalopram in psychiatric patients. One hundred and sixty-six patients treated with escitalopram were divided into the following subgroups according to CYP2C19 genotype: CYP2C19*17/*17 (n=7), CYP2C19*1/*17 (n=43), CYP2C19*1/*1 (n=60), CYP2C19*17/def (n=16), CYP2C19*1/def (n=34), and CYP2C19def/def (n=6) (def=defective allele, i.e., CYP2C19*2 or *3). Dose-adjusted serum concentrations of escitalopram were compared using the CYP2C19*1/*1 subgroup as reference. Geometric mean of the escitalopram serum concentration was 42% lower in patients homozygous for CYP2C19*17 (P<0.01) and 5.7-fold higher in subjects homozygous for defective CYP2C19 alleles (P<0.001). Of the heterozygous subgroups, only CYP2C19*1/def was significantly different from CYP2C19*1/*1 (P<0.001). In conclusion, a homozygous CYP2C19*17 genotype is associated with lower serum concentration of escitalopram, which might imply increased risk of therapeutic failure.

The CYP2C19 genotype had a substantial impact on exposure and therapeutic failure of escitalopram, as measured by switching of antidepressant therapy. The results support the potential clinical utility of CYP2C19 genotyping for individualization of escitalopram therapy.

This international guideline proposes improving clozapine package inserts worldwide by using ancestry-based dosing and titration. Adverse drug reaction (ADR) databases suggest that clozapine is the third most toxic drug in the United States (US), and it produces four times higher worldwide pneumonia mortality than that by agranulocytosis or myocarditis. For trough steady-state clozapine serum concentrations, the therapeutic reference range is narrow, from 350 to 600 ng/mL with the potential for toxicity and ADRs as concentrations increase. Clozapine is mainly metabolized by CYP1A2 (female non-smokers, the lowest dose; male smokers, the highest dose). Poor metabolizer status through phenotypic conversion is associated with co-prescription of inhibitors (including oral contraceptives and valproate), obesity, or inflammation with C-reactive protein (CRP) elevations. The Asian population (Pakistan to Japan) or the Americas’ original inhabitants have lower CYP1A2 activity and require lower clozapine doses to reach concentrations of 350 ng/mL. In the US, daily doses of 300–600 mg/day are recommended. Slow personalized titration may prevent early ADRs (including syncope, myocarditis, and pneumonia). This guideline defines six personalized titration schedules for inpatients: 1) ancestry from Asia or the original people from the Americas with lower metabolism (obesity or valproate) needing minimum therapeutic dosages of 75–150 mg/day, 2) ancestry from Asia or the original people from the Americas with average metabolism needing 175–300 mg/day, 3) European/Western Asian ancestry with lower metabolism (obesity or valproate) needing 100–200 mg/day, 4) European/Western Asian ancestry with average metabolism needing 250–400 mg/day, 5) in the US with ancestries other than from Asia or the original people from the Americas with lower clozapine metabolism (obesity or valproate) needing 150–300 mg/day, and 6) in the US with ancestries other than from Asia or the original people from the Americas with average clozapine metabolism needing 300–600 mg/day. Baseline and weekly CRP monitoring for at least four weeks is required to identify any inflammation, including inflammation secondary to clozapine rapid titration.

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Pharmacist-initiated drug changes significantly reduced ADS score but did not improve cognitive function in nursing home residents. Moreover, the drug changes did not reduce SAA or mouth dryness significantly, which might indicate limited applicability of the ADS score to prevent prescription risks in this population.

This study disclosed a distinct difference in the pharmacokinetics of atorvastatin metabolites between patients with atorvastatin-related myopathy and healthy control subjects. These results are of importance in the further search for the mechanism of statin-induced myopathy.