Yoshimoto Sekine

Orbitofrontal cortex abnormality and deficit schizophrenia

Deficit syndrome, which is characterized by primary and enduring negative symptoms, is a homogeneous subtype within schizophrenia. Negative symptoms in schizophrenia are currently considered to be closely linked with frontal lobe impairment. However, the etiology in the frontal lobe of people with deficit syndrome is not fully understood. We measured regional cerebral blood flow (rCBF) with single photon emission computed tomography (SPECT) in 33 patients with deficit syndrome, 40 patients with nondeficit syndrome, and 45 healthy controls, and we compared groups using the voxel-wise method. Schizophrenia combined group, the deficit syndrome and the nondeficit syndrome presented hypoperfusion in mainly the medial and lateral prefrontal cortices. The deficit syndrome group showed a significant decrease in rCBF in the right orbitofrontal cortex (OFC) compared to the nondeficit group. These results demonstrated that at-rest hypofrontality was a common feature within the disease group and suggested that the OFC might play an important role in the development of severe negative symptoms in people with deficit syndrome.

Chronic Treatment With Aripiprazole Prevents Development of Dopamine Supersensitivity and Potentially Supersensitivity Psychosis

BACKGROUND Long-term treatment of schizophrenia with antipsychotics is crucial for relapse prevention, but a prolonged blockade of D(2) dopamine receptors may lead to the development of supersensitivity psychosis. We investigated the chronic effects of aripiprazole (ARI) on dopamine sensitivity. METHODS We administered ARI (1.5 mg/kg/d), haloperidol (HAL; 0.75 mg/kg/d), or vehicle (VEH) via minipump for 14 days to drug-naive rats or to rats pretreated with HAL (0.75 mg/kg/d) or VEH via minipump for 14 days. On the seventh day following treatment cessation, we examined the effects of the treatment conditions on the locomotor response to methamphetamine and on striatal D(2) receptor density (N = 4-10/condition/experiment). RESULTS Chronic treatment with HAL led to significant increases in locomotor response and D(2) receptor density, compared with the effects of chronic treatment with either VEH or ARI; there were no significant differences in either locomotor response or D(2) density between the VEH- and ARI-treated groups. We also investigated the effects of chronic treatment with HAL, ARI, or VEH preceded by HAL or VEH treatment on locomotor response and D(2) density. ANOVA analysis indicated that the rank ordering of groups for both locomotor response and D(2) density was HAL-HAL > HAL-VEH > HAL-ARI > VEH-VEH. CONCLUSIONS Chronic treatment with ARI prevents development of dopamine supersensitivity and potentially supersensitivity psychosis, suggesting that by reducing excessive sensitivity to dopamine and by stabilizing sensitivity for an extended period of time, ARI may be helpful for some patients with treatment-resistant schizophrenia.

A prospective comparative study of risperidone long-acting injectable for treatment-resistant schizophrenia with dopamine supersensitivity psychosis

OBJECTIVE Dopamine supersensitivity psychosis (DSP) is considered to be one cause of treatment-resistant schizophrenia (TRS). The authors investigated the efficacy of risperidone long-acting injections (RLAI) in patients with TRS and DSP. METHOD This is a multicenter, prospective, 12-month follow-up, observational study that included unstable and severe TRS patients with and without DSP. 115 patients with TRS were recruited and divided into two groups according to the presence or absence of DSP which was judged on the basis of the clinical courses and neurological examinations. RLAI was administered adjunctively once every 2weeks along with oral antipsychotics. We observed changes in scores for the Brief Psychiatric Rating Scales (BPRS), Clinical Global Impression-Severity of Illness (CGI-S), Global Assessment of Functioning Scale (GAF), and Extrapyramidal Symptom Rating Scale (ESRS) during the study. Of the assessed 94 patients, 61 and 33 were categorized into the DSP and NonDSP groups, respectively. RESULTS While baseline BPRS total scores, CGI-S scores and GAF scores did not differ, the ESRS score was significantly higher in the DSP group compared with the NonDSP group. Treatment significantly reduced BPRS total scores and CGI-S scores, and increased GAF scores in both groups, but the magnitudes of change were significantly greater in the DSP group relative to the NonDSP group. ESRS scores were also reduced in the DSP group. Responder rates (≥20% reduction in BPRS total score) were 62.3% in the DSP group and 21.2% in the NonDSP group. CONCLUSIONS It is suggested that DSP contributes to the etiology of TRS. Atypical antipsychotic drugs in long-acting forms, such as RLAI, can provide beneficial effects for patients with DSP. CLINICAL TRIALS REGISTRATION UMIN (UMIN000008487).

A case of methamphetamine use disorder treated with the antibiotic drug minocycline

Methamphetamine (METH) use is one of the major public health concerns worldwide. Long-term use of METH induces not only dependence but also psychosis which is associated with METH-induced brain damage, including neuroinflammation produced by activated microglia. We report the case of a female patient whose psychotic symptoms in METH use disorder were successfully improved by anti-inflammatory drug minocycline therapy. Although the precise mechanism(s) underlying the efficacy of minocycline in METH use disorder are currently unclear, minocycline appears to be a good candidate for future investigation clinical trials for medication development in METH using populations.

Does hypofrontality expand to global brain area in progression of schizophrenia?: a cross-sectional study between first-episode and chronic schizophrenia.

Although to date there have been no conclusive pathophysiological findings in support of the degenerative theory of the etiology of schizophrenia, the results of neuroimaging studies have suggested that progressive changes in the brain do occur during the clinical course of schizophrenia. However, there has been no report on alterations in regional cerebral blood flow (rCBF) under resting condition, which was compared between the first-episode and the chronic patients of schizophrenia and healthy controls. Therefore, in this study, we applied three-dimensional stereotactic surface projection analysis of resting SPECT (3D-SSP SPECT) in patients with first-episode (n=18) and chronic schizophrenia (n=23) and age-/sex-matched healthy controls (n=40). The rCBFs in the middle/inferior/medial frontal gyrus and the anterior cingulate gyrus were significantly decreased in both patient groups, relative to the respective controls (Z>3.0, P<0.001, uncorrected). The chronic group showed significant hypoperfused region in the left inferior parietal lobule and middle/inferior temporal gyrus. Furthermore, within-cases comparison between the first-episode and chronic schizophrenia, revealed that the significant hypoperfused regions in the chronic group, compared to the first-episode group, were not only the lateral and medial prefrontal cortex, but also the inferior parietal cortex, posterior part of the temporal lobe, and the cuneus. The present study suggested that the reduction in rCBF occurs in the posterior brain area in addition to the frontal lobe across all clinical stages of schizophrenia.

Effectiveness of Information Technology Aided Relapse Prevention Programme in Schizophrenia excluding the effect of user adherence: a randomized controlled trial.

BACKGROUND A relapse prevention program called the Information Technology Aided Relapse Prevention Programme in Schizophrenia (ITAREPS) has been developed and is reported to be highly effective. However the effectiveness was influenced by user adherence to the protocol of the program, the exact effectiveness and the role of the ITAREPS have been partially uncertain. OBJECTIVE The purpose of this study is to evaluate the effectiveness of the ITAREPS excluding the effect of user adherence to the protocol of the program. METHOD We attempted to perform a randomized controlled trial by the devised method with visiting nurse service. Outpatients with schizophrenia were randomized to the ITAREPS (n=22) or control group (n=23) and were observed for 12 months. RESULTS The risk of rehospitalization was reduced in the ITAREPS group (2 [9.1%]) compared with the control group (8 [34.8%]) (hazard ratio=0.21, 95% CI 0.04-0.99, p=0.049; number needed to treat (NNT)=4, 95% CI 2.1-35.5). The mean number of inpatient days was significantly lower in the ITAREPS group (18.5 days) compared with the control group (88.8 days) (p=0.036). The ratio of the number of rehospitalizations to that of relapses was significantly lower (p=0.035) and the mean change in total BPRS scores at relapse from baseline was significantly less in the ITAREPS group (p=0.019). CONCLUSIONS The relapse prevention effectiveness of the ITAREPS was high, and we confirmed that the ITAREPS, i.e., detecting signs of relapse and increasing medication during the warning state, is an effective intervention during the early stages of relapse.

The adenosine A2A receptor is associated with methamphetamine dependence/psychosis in the Japanese population

BackgroundSeveral lines of evidence suggest that the dopaminergic nervous system contributes to methamphetamine (METH) dependence, and there is increasing evidence of antagonistic interactions between dopamine and adenosine receptors. We therefore hypothesized that variations in the A2A adenosine receptor (ADORA2A) gene modify genetic susceptibility to METH dependence/psychosis.MethodsWe first analyzed variations in the exons and exon-intron boundaries of the ADORA2A gene in METH dependent/psychotic patients. Then an association analysis between these single nucleotide polymorphisms and METH dependence/psychosis was performed using a total of 171 METH dependent/psychotic patients and 229 controls.ResultsWe found 6 variations, of which one single nucleotide polymorphism (SNP) was novel. Significant associations were observed between the allelic and genotypic frequencies of the Exon2+751 (rs5751876) SNP and METH dependence/psychosis. These associations were observed especially in females. In the clinical feature analyses, significant associations were observed between the SNP and the patient subgroup using METH alone (i.e., without concomitant use of other substances of abuse).ConclusionsThese results suggest that the ADORA2A gene could be a vulnerability factor for METH dependence/psychosis, especially in females and/or in patients using only METH.

Onset Pattern and Long-Term Prognosis in Schizophrenia: 10-Year Longitudinal Follow-Up Study.

Background Although the duration of untreated psychosis (DUP) plays an important role in the short-term prognosis of patients with schizophrenia, their long-term prognosis generally is not determined by DUP alone. It is important to explore how other clinical factors in the early stage are related to DUP and consequent disease courses. Methods A total of 664 patients with untreated psychosis were surveyed for this study. At the first examination, we divided them into the severe positive symptoms cases (SC) or the less severe cases (NonSC) and compared the prognosis among the two groups after a 10-year follow-up. In all, 113 patients in the SC group and 43 patients in the NonSC group were follow-up completers. Results Whereas DUP was not different between the two groups, patients with nonacute onset in both groups had significantly longer DUP than those in patients with acute onset. For all clinical measures, there was no difference in prognosis between the two groups or among the four groups classified by mode of onset (MoO) and initial severity of positive symptoms. However, the degree of improvement of global assessment of functioning (GAF) was significantly smaller in the NonSC-nonacute group than in the SC-acute and SC-nonacute groups. Conclusions These results suggest that neither DUP nor MoO alone necessarily affects the initial severity of positive symptoms. Moreover, it is possible that patients with low impetus of positive symptoms onset within long DUP experience profound pathologic processes. Therefore, the current study results indicated that long DUP and nonacute onset were related to poor long-term prognosis, regardless of initial positive symptoms.

Association analysis of the adenosine A1 receptor gene polymorphisms in patients with methamphetamine dependence/psychosis.

Several lines of evidence suggest that the dopaminergic nervous system contributes to methamphetamine (METH) dependence, and there is increasing evidence of antagonistic interactions between dopamine and adenosine receptors in METH abusers. We therefore hypothesized that variations in the A1 adenosine receptor (ADORA1) gene modify genetic susceptibility to METH dependence/psychosis. In this study, we identified 7 single nucleotide polymorphisms (SNPs) in exons and exon-intron boundaries of the ADORA1 gene in a Japanese population. A total of 171 patients and 229 controls were used for an association analysis between these SNPs and METH dependence/psychosis. No significant differences were observed in either the genotypic or allelic frequencies between METH dependent/psychotic patients and controls. A global test of differentiation among samples based on haplotype frequencies showed no significant association. In the clinical feature analyses, no significant associations were observed among latency of psychosis, prognosis of psychosis, and spontaneous relapse. These results suggest that the ADORA1 gene variants may make little or no contribution to vulnerability to METH dependence/psychosis.

Association Analysis of the Tryptophan Hydroxylase 2 Gene Polymorphisms in Patients with Methamphetamine Dependence/Psychosis

There is a growing evidence that serotoninergic systems modulate dopaminergic neurotransmission. We analyzed the association between the variations in the brain tryptophan hydroxylase 2 (TPH2) gene, a rate limiting enzyme for serotonin biosynthesis, and methamphetamine (METH) dependence/psychosis in a Japanese population. We found ten single nucleotide polymorphisms (SNPs) and two polynucleotide polymorphisms in TPH2 gene exons and exon-intron boundaries. A total of 162 patients and 243 controls were used for the association analysis between these polymorphisms and METH dependence/psychosis. No significant differences were observed in either genotypic or allelic frequencies between METH dependent/psychotic patients and controls. A global test of differentiation among samples based on haplotype frequencies showed no significant association. With respect to latency of psychosis, prognosis of psychosis, and spontaneous relapse, we found no significant association with these SNPs. These results suggest that the TPH2 gene variants may not be a factor in vulnerability to METH dependence/psychosis.