Hiroshi Mitsuyasu

Comparative efficacy and tolerability of pharmacological treatments in the maintenance treatment of bipolar disorder: a systematic review and network meta-analysis

BACKGROUND Lithium is the established standard in the long-term treatment of bipolar disorder, but several new drugs have been assessed for this indication. We did a network meta-analysis to investigate the comparative efficacy and tolerability of available pharmacological treatment strategies for bipolar disorder. METHODS We systematically searched Embase, Medline, PreMedline, PsycINFO, and the Cochrane Central Register of Controlled Trials for randomised controlled trials published before June 28, 2013, that compared active treatments for bipolar disorder (or placebo), either as monotherapy or as add-on treatment, for at least 12 weeks. The primary outcomes were the number of participants with recurrence of any mood episode, and the number of participants who discontinued the trial because of adverse events. We assessed efficacy and tolerability of bipolar treatments using a random-effects network meta-analysis within a Bayesian framework. FINDINGS We screened 114 potentially eligible studies and identified 33 randomised controlled trials, published between 1970 and 2012, that examined 17 treatments for bipolar disorder (or placebo) in 6846 participants. Participants assigned to all assessed treatments had a significantly lower risk of any mood relapse or recurrence compared with placebo, except for those assigned to aripiprazole (risk ratio [RR] 0·62, 95% credible interval [CrI] 0·38-1·03), carbamazepine (RR 0·68, 0·44-1·06), imipramine (RR 0·95, 0·66-1·36), and paliperidone (RR 0·84, 0·56-1·24). Lamotrigine and placebo were significantly better tolerated than carbamazepine (lamotrigine, RR 5·24, 1·07-26·32; placebo, RR 3·60, 1·04-12·94), lithium (RR 3·76, 1·13-12·66; RR 2·58, 1·33-5·39), or lithium plus valproate (RR 5·95, 1·02-33·33; RR 4·09, 1·01-16·96). INTERPRETATION Although most of the drugs analysed were more efficacious than placebo and generally well tolerated, differences in the quality of evidence and the side-effect profiles should be taken into consideration by clinicians and patients. In view of the efficacy in prevention of both manic episode and depressive episode relapse or recurrence and the better quality of the supporting evidence, lithium should remain the first-line treatment when prescribing a relapse-prevention drug in patients with bipolar disorder, notwithstanding its tolerability profile. FUNDING None.

Association analysis of polymorphisms in the upstream region of the human dopamine D4 receptor gene (DRD4) with schizophrenia and personality traits.

AbstractThe human dopamine D4 receptor (DRD4) is of major interest in molecular studies of schizophrenia and personality traits. We examined the association of schizophrenia and polymorphisms in the upstream region of the DRD4 gene (−768G>A in the negative modulator region; −521C>T, −376C>T, and −291C>T in the cell type-specific promoter region; and −616C>G between the two regions) in 208 schizophrenic patients and 210 normal controls. No significant difference in genotype and allele frequencies was observed between the two groups, indicating that these polymorphisms do not make a major contribution to the pathogenesis of schizophrenia. We also studied the association of polymorphisms in the upstream region and a 48-bp repeat polymorphism in exon III of the DRD4 gene with personality traits in 173 Japanese individuals who completed the temperament and character inventory (TCI). The −768G>A polymorphism was significantly associated with reward dependence (P = 0.044), while no significant association was observed between novelty seeking and polymorphisms in the upstream region or the exon III repeat polymorphism of the DRD4 gene.

Novel polymorphisms in the upstream region of the human dopamine D4 receptor (DRD4) gene

AbstractWe found nine novel polymorphisms in the upstream region of the human dopamine D4 receptor (DRD4) gene of Japanese by direct sequencing. These polymorphisms are −809G > A, −768G > A, −616C > G, −603T > del, −602G > del, −600G > C, −376C > T, −291C > T, and −128G > T. One known polymorphism, −521C > T, was also recognized. Six of these sites were identified as restriction fragment length polymorphisms (RFLPs).

Association analysis of adenosine A1 receptor gene (ADORA1) polymorphisms with schizophrenia in a Japanese population

Objective The human adenosine A1 receptor gene (ADORA1) localizes to chromosome 1q32 is 76.8 kbp in length and contains six exons. ADORA1 is ubiquitously expressed in the central nervous system and clinical and pharmacological evidence suggest the involvement of adenosine neurotransmission in the pathogenesis of schizophrenia. Therefore, we investigated the contribution of genetic variations of ADORA1 to the pathophysiological mechanisms of Japanese schizophrenia patients. Methods We performed genetic analysis of 29 polymorphic markers in 200 schizophrenic patients and 210 healthy controls from the Kyushu region of Japan. In statistical analysis, we performed the univariate analysis with genotypes and allele frequencies, linkage disequilibrium (LD) analyses, multivariate analysis, haplotype analysis, and sliding window haplotype analysis. Results In univariate analysis, no statistical difference was shown, after Bonferroni correction. By LD analysis, however, we could not find any LD blocks. In haplotype analysis, a total of 359 haplotypes were estimated. In multivariate analysis, we found three statistically different markers. In sliding window haplotype analysis, there were four statistically different haplotypes. Conclusion This is the first study describing the involvement of ADORA1 polymorphisms in the pathophysiological mechanisms of schizophrenia in a Japanese population. These results corroborate our previous pharmacological and neurochemical studies in the rat that have suggested an association between ADORA1 neurotransmission and the schizophrenic effects of the N-methyl-D-aspartate receptor antagonist phencyclidine. Thus, ADORA1 polymorphisms may represent good candidate markers for schizophrenia research and ADORA1 may be involved in the pathophysiological mechanisms of schizophrenia in Japanese populations.

Nominal association between a polymorphism in DGKH and bipolar disorder detected in a meta-analysis of East Asian case-control samples

Aim:  Recent genome‐wide association studies (GWAS) of bipolar disorder (BD) have detected new candidate genes, including DGKH, DFNB31 and SORCS2. However, the results of these GWAS were not necessarily consistent, indicating the importance of replication studies. In this study, we tested the genetic association of DGKH, DFNB31 and SORCS2 with BD.

Using the contribution matrix to evaluate complex study limitations in a network meta-analysis: a case study of bipolar maintenance pharmacotherapy review

BackgroundLimitations in the primary studies constitute one important factor to be considered in the grading of recommendations assessment, development, and evaluation (GRADE) system of rating quality of evidence. However, in the network meta-analysis (NMA), such evaluation poses a special challenge because each network estimate receives different amounts of contributions from various studies via direct as well as indirect routes and because some biases have directions whose repercussion in the network can be complicated.FindingsIn this report we use the NMA of maintenance pharmacotherapy of bipolar disorder (17 interventions, 33 studies) and demonstrate how to quantitatively evaluate the impact of study limitations using netweight, a STATA command for NMA. For each network estimate, the percentage of contributions from direct comparisons at high, moderate or low risk of bias were quantified, respectively. This method has proven flexible enough to accommodate complex biases with direction, such as the one due to the enrichment design seen in some trials of bipolar maintenance pharmacotherapy.ConclusionsUsing netweight, therefore, we can evaluate in a transparent and quantitative manner how study limitations of individual studies in the NMA impact on the quality of evidence of each network estimate, even when such limitations have clear directions.

A pilot study exploring the association of morphological changes with 5-HTTLPR polymorphism in OCD patients

BackgroundClinical and pharmacological studies of obsessive-compulsive disorder (OCD) have suggested that the serotonergic systems are involved in the pathogenesis, while structural imaging studies have found some neuroanatomical abnormalities in OCD patients. In the etiopathogenesis of OCD, few studies have performed concurrent assessment of genetic and neuroanatomical variables.MethodsWe carried out a two-way ANOVA between a variable number of tandem repeat polymorphisms (5-HTTLPR) in the serotonin transporter gene and gray matter (GM) volumes in 40 OCD patients and 40 healthy controls (HCs).ResultsWe found that relative to the HCs, the OCD patients showed significant decreased GM volume in the right hippocampus, and increased GM volume in the left precentral gyrus. 5-HTTLPR polymorphism in OCD patients had a statistical tendency of stronger effects on the right frontal pole than those in HCs.ConclusionsOur results showed that the neuroanatomical changes of specific GM regions could be endophenotypes of 5-HTTLPR polymorphism in OCD.