Ikuko Kishida

Prevalence of metabolic syndrome among patients with schizophrenia in Japan

AIMS In an Asian population, the criteria for metabolic syndrome (MetS) are different from those for Western populations. The aim of this study was to assess the MetS prevalence among patients with schizophrenia or schizoaffective disorder in Japan. METHODS We recruited patients (n=1186), aged 54.8±14.8 (mean±SD) years old with the DSM-IV diagnosis of schizophrenia or schizoaffective disorder who were admitted to seven psychiatric hospitals using a cross-sectional design. MetS prevalence was assessed by three different definitions, including the adapted National Cholesterol Education Program Adult Treatment Panel (ATP III-A). Comparative analysis was performed with schizophrenic subjects and 886 participants from the Iwaki Health Promotion Project 2008 as representative of general population. RESULTS The overall MetS prevalence based on the ATP III-A definition was 27.5%, with 29.8% in male and 25.3% in female patients. In a logistic regression model with age and body mass index as covariates, being schizophrenic was a significant independent factor (odds ratio=2.00 for males, 2.13 for females) in the development of MetS under the ATP III-A definition. The difference of MetS prevalence between patients and the general population was observed for those under 60 years of age. CONCLUSIONS Patients with schizophrenia or schizoaffective disorder in Japan had high prevalence of MetS compared to the general population, and was most apparent for those under 60 years of age. The MetS in schizophrenic patients should be carefully monitored to minimize the risks.

Association in Japanese patients between neuroleptic malignant syndrome and functional polymorphisms of the dopamine D 2 receptor gene

A genetic predisposition to the development of neuroleptic malignant syndrome (NMS) has been suggested by clinical studies. Although the molecular basis of NMS is unclear, a dopaminergic blockade mechanism has been considered the main cause. We therefore investigated the association between NMS and three functional polymorphisms of the dopamine D2 receptor (DRD2) gene: TaqI A, −141C Ins/Del, and Ser311Cys. Subjects included 32 Japanese patients, previously diagnosed with NMS, and 132 schizophrenic patients treated with neuroleptics without occurrence of NMS. Polymerase chain reaction and restriction fragment length polymorphism analyses were performed to determine each genotype. We found significant differences in genotypic and allelic frequencies of the –141C Ins/Del polymorphism between patients with and without NMS. The −141C Del allele was significantly more frequent in the NMS group (23.4 vs 11.7%, P=0.026). Similarly, the proportion of −141C Del allele carriers was significantly higher in the NMS group (40.6 vs 20.5%, P=0.022). No significant differences between the two groups were seen for allelic and genotypic frequencies of the TaqI A and Ser311Cys polymorphisms. This result suggests that the −141C Ins/Del polymorphism is likely to predispose toward the development of NMS, probably together with other unidentified factors.

Psychiatric assessment of suicide attempters in Japan: a pilot study at a critical emergency unit in an urban area

BackgroundThe incidence of suicide has increased markedly in Japan since 1998. As psychological autopsy is not generally accepted in Japan, surveys of suicide attempts, an established risk factor of suicide, are highly regarded. We have carried out this study to gain insight into the psychiatric aspects of those attempting suicide in Japan.MethodsThree hundred and twenty consecutive cases of attempted suicide who were admitted to an urban emergency department were interviewed, with the focus on psychosocial background and DSM-IV diagnosis. Moreover, they were divided into two groups according to the method of attempted suicide in terms of lethality, and the two groups were compared.ResultsNinety-five percent of patients received a psychiatric diagnosis: 81% of subjects met the criteria for an axis I disorder. The most frequent diagnosis was mood disorder. The mean age was higher and living alone more common in the high-lethality group. Middle-aged men tended to have a higher prevalence of mood disorders.ConclusionThis is the first large-scale study of cases of attempted suicide since the dramatic increase in suicides began in Japan. The identification and introduction of treatments for psychiatric disorders at emergency departments has been indicated to be important in suicide prevention.

Autonomic nervous system activity and psychiatric severity in schizophrenia

Aims:  Schizophrenia patients have a mortality rate two to three‐fold higher than that of the general population. Despite the disorders widespread recognition, how and to what extent autonomic nervous system (ANS) activity contributes to schizophrenia remains inconclusive. The aim of the present study, therefore, was to determine the extent of ANS activity depression with respect to healthy, well‐matched control subjects and the severity of psychiatric disorders as determined using the Global Assessment of Functioning (GAF) scale among schizophrenia patients with special reference to antipsychotic dose.

MAO-A and COMT genotypes as possible regulators of perinatal serotonergic symptoms after in utero exposure to SSRIs

Intrauterine exposure to SSRIs in late pregnancy can cause various serotonergic symptoms in the newborns. We associated the severity of these symptoms to neurotransmitter concentrations and genetic polymorphisms in the cytochrome P450, MAO-A and COMT enzymes. Altogether 20 children with prenatal exposure to citalopram or fluoxetine were genotyped. Infants with two high-activity alleles of the MAO-A gene had significantly higher serotonergic symptom scores than infants with at least one low-activity allele (mean 8.8 vs. 2.4, p=0.024). These infants had also higher cord blood DHPG concentrations (p=0.0054). Carriers of the high-activity COMT alleles had higher cord blood prolactin concentrations (p=0.044). According to our results, the higher serotonergic symptom score and cord blood DHPG concentration in rapid MAO-A metabolizers suggest that norepinephrine may modify the severity of perinatal serotonergic symptoms. The COMT 1947G>A polymorphism may affect the occurrence of respiratory distress symptoms in infants with prenatal SSRI-exposure via a mechanism involving prolactin.

Dopamine D2 receptor gene polymorphisms are associated with suicide attempt in the Japanese population.

Background: Some reports have suggested the involvement of the D2 dopaminergic function in the expression of suicidal behavior. Here, we examined associations between suicide attempts and two kinds of functional polymorphisms in the dopamine D2 receptor (DRD2) gene, namely, TaqIA and –141C Ins/Del. Methods: Subjects included 120 suicide attempters and 123 unrelated volunteers. Those who attempted suicide were severely injured and were transferred to the emergency unit in our university hospital. To determine each genotype, we performed polymerase chain reaction and restriction fragment length polymorphism analyses. Results: We found significant differences in genotypic and allelic frequencies of –141C Ins/Del and TaqIA polymorphisms between suicide attempters and healthy controls (–141C Ins/Del, p = 0.01; TaqIA,p = 0.036). The Ins allele of –141C Ins/Del was significantly more frequent in suicide attempters (p = 0.011), as well as the A2 allele of TaqIA (p = 0.017). Haplotype analysis revealed no significant linkage disequilibrium between –141C Ins/Del and TaqIA polymorphisms (D′ = 0.226, r2 = 0.016, p = 0.10). Conclusions: These findings suggest that DRD2 gene polymorphisms may be involved in the biological susceptibility to suicide.

Monoamine Metabolites Level in CSF is Related to the 5-HTT Gene Polymorphism in Treatment-Resistant Depression

The serotonin (5-hydroxytryptamine) transporter (5-HTT) is considered to affect the pathogenesis of mood disorders. Large number of genetic association studies between 5-HTT functional polymorphisms and vulnerability of mood disorders and therapeutic response to antidepressants has been carried out. We investigated the influence of 5-HTT-linked polymorphic region (5-HTTLPR) and 5-HTT 17 bp variable number of tandem repeat polymorphism (5-HTTVNTR) polymorphisms on concentrations of monoamine metabolites in cerebrospinal fluid (CSF) among treatment-resistant patients with mood disorders. Subjects were 119 Swedish patients with persistent mood disorders and 141 healthy subjects. In 112 of these patients, we measured 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid (HVA), and 3-methoxy-4-hydroxyphenylglycol in CSF. Genotyping for 5-HTT polymorphisms from genomic DNA was carried out by PCR. There was no significant difference in allele/genotype frequency between patients and healthy subjects. In patients with mood disorders, we found significant difference in mean 5-HIAA concentration between 5-HTTLPR genotypes (p=0.03). Although the 5-HIAA concentration showed a tendency to be higher in short (S) carriers than in non-S carriers of the 5-HTTLPR in patients (p=0.06), when considering patients with major depressive disorder (MDD), the 5-HIAA concentration was significantly higher among S carriers than among non-S carriers (p=0.02). Moreover, the 5-HIAA concentration was higher in S/S subjects compared to long (L)/L (p=0.0001) and L/S (p=0.002) subjects in patients with MDD. Similarly, there was higher HVA concentration in S/S subjects compared to L/L (p=0.002) and L/S subjects (p=0.002). There was no effect of 5-HTTVNTR. Our findings show that the 5-HTTLPR polymorphism affects 5-HIAA and HVA concentrations among treatment-resistant patients with mood disorders.

Effects of CYP2D6 polymorphisms on neuroleptic malignant syndrome

ObjectiveNeuroleptic malignant syndrome (NMS) is one of the most serious adverse reactions to antipsychotic medications. We accumulated data on Japanese NMS patients and, in a study designed to examine the effects of drug metabolism on the occurrence of NMS, tested the possibility of association between NMS and CYP2D6 polymorphisms.MethodsWe studied 53 patients who had experienced NMS and 112 healthy individuals. We determined what drugs the patients with NMS had been given and retrospectively identified candidates for drugs causing NMS. We screened the prevalence of CYP2D6 genotypes using polymerase chain reaction and restriction fragment length polymorphism analyses.ResultsThe prevalence of *5 alleles in the group of all patients with NMS was higher than that in the controls, though this difference was not statistically significant (10.4% vs. 5.4%; P = 0.107; odds ratio (OR) 2.05; 95% confidence interval (CI) 0.87–4.80). No association was found between the frequency of *10 alleles and the occurrence of NMS. We found *4 and duplicated alleles in only one patient each among the patients with NMS. A total of 29 patients appeared to have developed NMS as a result of having taking CYP2D6 substrates. The prevalence of *5 alleles in these 29 patient was significantly higher than that in the controls (15.5% vs. 5.4%; P = 0.020; OR 3.25; 95% CI 1.30–8.13).ConclusionOur findings suggest that the CYP2D6*5 allele is likely to affect vulnerability to development of NMS.

Dose-dependent effect of antipsychotic drugs on autonomic nervous system activity in schizophrenia

BackgroundAntipsychotic drugs are considered a trigger factor for autonomic dysregulation, which has been shown to predict potentially fatal arrhythmias in schizophrenia. However, the dose-dependent effect of antipsychotic drugs and other psychotropic drugs on autonomic nervous system (ANS) activity remain unclear. The purpose of this study was to investigate the dose-dependent effect of antipsychotic drugs and other clinical factors on ANS activity in an adequate sample size of patients with schizophrenia.MethodsA total of 211 Japanese patients with schizophrenia and 44 healthy subjects participated in this study. ANS activity was assessed by means of heart rate variability (HRV) power spectral analysis. Antipsychotic drug treatment and various clinical factors were investigated for each participant. The patient group was categorized into three subgroups according to daily dose of antipsychotic drug, and HRV was compared between groups.ResultsThe results showed significantly decreased low-frequency and high-frequency components of HRV in the patient group compared to the control group. The high-dose group showed a significantly lower HRV than the medium-dose group and an even lower HRV than the low-dose group. In addition, a significant association between HRV and antipsychotic drug dose was identified by multiple regression analysis. HRV was not associated with age, sex, body mass index, duration of illness, or daily dose of other psychotropic drugs.ConclusionThese results suggest that antipsychotic drugs exert a significant dose-dependent effect on the extent of decline in ANS activity, and that optimal antipsychotic medication is required to avoid possible cardiovascular adverse events in patients with schizophrenia.

Knowledge and attitude towards suicide among medical students in Japan: preliminary study.

Abstract  Japan has one of the highest suicide rates in the world. Suicides numbered 32 863 in 1998 and have exceeded 30 000 in every subsequent year. Education of those involved in general and psychosocial patient care can contribute greatly to suicide prevention. The authors administered a brief knowledge and attitude assessment questionnaire concerning suicide to students in their first, third, and fifth years at a Japanese medical school. Participants numbered 160 (94 men with a mean age of 21.8 years, SD = 3.01, and 66 women with a mean age of 21.2 years, SD = 2.64); 59 first year, 52 third year, and 49 in their fifth year. The questionnaire consists of eight multiple‐choice questions asking knowledge of suicide and one open‐ended question asking attitude. In the knowledge part, only about half of the items were answered correctly (mean score was 4.21, SD = 1.28). A significant difference was observed in prevalence of attitudes as categorical variables between student years (P = 0.001). Sympathetic comments increased along with student years, while critical comments decreased. Given the frequent and interventional opportunities of primary‐care medical contacts, poor understanding of suicide from the medical viewpoint was of concern. Moreover, judgmental attitudes were common, especially in earlier school years. Better informed, more understanding physicians and other health professionals could contribute greatly to prevention.