This meta-analysis was conducted to evaluate whether HTR1A gene polymorphisms impact the efficacy of antipsychotic drugs in patients with schizophrenia. Candidate gene studies that were published in English up to August 6, 2015 were identified by a literature search of PubMed, Web of Science, and Google scholar. Data were pooled from individual clinical trials considering overall symptoms, positive symptoms and negative symptoms, and standard mean differences were calculated by applying a random-effects model. The present meta-analysis included a total of 1281 patients from 10 studies. Three polymorphisms of HTR1A (rs6295, rs878567, and rs1423691) were selected for the analysis. In the pooled data from all studies, none of these HTR1A polymorphisms correlated significantly with either overall symptoms or positive symptoms. However, C allele carriers of the rs6295 polymorphism showed a significantly greater negative symptoms improvement than G allele carriers (P=.04, standardized mean difference =-0.14, 95%CI = 0.01 to 0.28). The results of our present analysis indicate that the HTR1A rs6295 polymorphism may impact negative symptoms improvement but not on either overall symptoms or positive symptoms improvement. However, this meta-analysis was based on a small number of studies and patients, and the effect size on negative symptoms was small. Given this limitation, the results should be confirmed by further investigations.
Background: Antidepressants have variable therapeutic effects, depending on genetic and environmental factors. Approximately 30% of major depressive disorder (MDD) patients do not respond significantly to antidepressants such as paroxetine, a selective serotonin reuptake inhibitor (SSRI). However, the biological mechanisms behind this phenomenon are mostly unknown. Here, we examined the role of patients' epigenetic background in SSRI efficacy. Methods: Genome-wide DNA methylation analysis of the peripheral blood of Japanese MDD patients was performed by using the Infinium HumanMethylation450 BeadChip. Results: We compared the results of the 10 patients who best responded to paroxetine (BR) with the 10 worst responders (WR), and found 623 CpG sites with a >10% difference in DNA methylation level. Among them, 218 sites were nominally significant between BR and WR (p < 0.05), and 2 sites (cg00594917 and cg07260927) were significantly different after false discovery rate (FDR) correction (q < 0.05). The methylation difference was greatest at cg00594917, located in the first exon of the PPFIA4 gene, which codes for liprin-α (p = 0.00012). Hierarchical cluster analysis of 23 CpG sites in the PPFIA4 gene distinguished BR and WR, except for 1 WR patient. The cg07260927 site was located in the 5′UTR of the heparin sulfate-glucosamine 3-sulfotransferase 1 (HS3ST1) gene (p = 0.00013). Hierarchical cluster analysis of 28 CpG sites in HS3ST1 distinguished BR and WR, except for 1 WR and 2 BR patients. Conclusion: Our results suggest that patients' DNA methylation profile at specific genes such as PPFIA4 and HS3ST1 is associated with individual variations in therapeutic responses to paroxetine.
Pharmacogenetics may allow for a personalized treatment, but a combination with clinical variables may further enhance prediction. In particular, in the present paper, we investigated early partial improvement (EPI) defined as 20% or more improvement by rating scales 2 weeks after treatment, in combination with selected gene variants as a predictor of treatment outcome in patients with major depressive disorder. Two randomized controlled trials with 168 Japanese depressed patients were used. A stepwise multiple linear regression model with HAM-D score change at week 6 as the dependent variable and genotypes, EPI, baseline HAM-D score, age and sex as independent variables was performed in paroxetine, fluvoxamine and milnacipran, respectively, to estimate the prediction of HAM-D change at week 6. In the paroxetine sample, only EPI (P<0.001) was significantly associated with HAM-D change (n=81, R2=0.25, P<0.001). In the fluvoxamine sample, 5-HTTLPR La/Lg, S (P=0.029), FGF2 rs1449683C/T (P=0.013) and EPI (P=0.003) were associated with HAM-D change (n=42, R2=0.43, P<0.001). In the milnacipran sample, HTR-1A-1019C/G (P=0.001), ADRA2A-1297C/G (P=0.028) and EPI (P<0.001) were associated with outcome (n=45, R2=0.71, P<0.001). EPI in combination with genetic variants could be a useful predictor of treatment outcome and could strengthen the practical use of pharmacogenetic data in clinical practice.
Purpose: The aim of this study was to compare the effects of risperidone long-acting injection (RLAI) and paliperidone palmitate (PP) on non-acute-phase social functioning in patients with schizophrenia. Patients and Methods: In this 6-month pilot, open-label, randomized controlled study, 30 patients with schizophrenia who had been treated with RLAI were randomly allocated to the RLAI continuation group or switched to the PP group. Patients were evaluated at baseline and 6 months with the Social Functioning Scale (SFS) as the primary outcome variable and University of California San Diego Performance-Based Skills Assessment Brief (UPSA-B), Social Emotional Cognition Task (SECT), Positive and Negative Syndrome Scale (PANSS), and Drug-Induced Extrapyramidal Symptoms Scale (DIEPSS) scores as secondary outcomes. Results: At baseline, the two groups did not significantly differ in demographic or clinical features. The two groups did not differ in total score changes for the UPSA-B, the SECT, the PANSS, and the DIEPSS. However, the total scores and the two subscales of the SFS, i.e. independence-competence and independence-performance, were more improved in the PP group compared to the RLAI group (total scores, p = 0.038; competence, p = 0.001, and performance, p = 0.007, respectively). Conclusion: These results suggest that PP may improve the total social functioning, independent life competence, and performance as compared to the RLAI group. However, these results are preliminary and need independent replication in larger samples before any definitive statement can be made.