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175 result(s) for "Iyo, Masaomi"
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Antipsychotic-Induced Dopamine Supersensitivity Psychosis
The first-line treatment for psychotic disorders remains antipsychotic drugs with receptor antagonist properties at D₂-like dopamine receptors. However, long-term administration of antipsychotics can upregulate D₂ receptors and produce receptor supersensitivity manifested by behavioral supersensitivity to dopamine stimulation in animals, and movement disorders and supersensitivity psychosis (SP) in patients. Antipsychotic-induced SP was first described as the emergence of psychotic symptoms with tardive dyskinesia (TD) and a fall in prolactin levels following drug discontinuation. In the era of first-generation antipsychotics, 4 clinical features characterized drug-induced SP: rapid relapse after drug discontinuation/dose reduction/switch of antipsychotics, tolerance to previously observed therapeutic effects, co-occurring TD, and psychotic exacerbation by life stressors. We review 3 recent studies on the prevalence rates of SP, and the link to treatment resistance and psychotic relapse in the era of second-generation antipsychotics (risperidone, paliperidone, perospirone, and long-acting injectable risperidone, olanzapine, quetiapine, and aripiprazole). These studies show that the prevalence rates of SP remain high in schizophrenia (30%) and higher (70%) in treatment-resistant schizophrenia. We then present neurobehavioral findings on antipsychotic-induced supersensitivity to dopamine from animal studies. Next, we propose criteria for SP, which describe psychotic symptoms and co-occurring movement disorders more precisely. Detection of mild/borderline drug-induced movement disorders permits early recognition of overblockade of D₂ receptors, responsible for SP and TD. Finally, we describe 3 antipsychotic withdrawal syndromes, similar to those seen with other CNS drugs, and we propose approaches to treat, potentially prevent, or temporarily manage SP.
Need for self-medication using over-the-counter psychoactive agents: A national survey in Japan
Self-medication using over-the-counter (OTC) drugs is an option for the autonomous treatment of several health problems. However, the use of OTC drugs to treat psychiatric conditions remains controversial. To clarify opinions regarding the use of OTC drugs to treat psychiatric problems, we conducted an anonymous online survey of 3000 people in Japan. Participants were stratified into three groups according to their history of mental health problems. Few participants had engaged in self-medication using OTC drugs for psychiatric symptoms, with the exception of insomnia. Participants who had used OTC drugs reported feeling less satisfied with their experience compared with those who had consulted a specialist. Participants who had used sleeping pills were likely to hold relatively positive opinions regarding the use of OTC psychiatric drugs. In conclusion, the need for self-medication of psychiatric symptoms appears to be limited. Education and further research may be necessary to promote self-medication for proper treatment of psychiatric conditions in Japan.
The alterations of glutamate transporter 1 and glutamine synthetase in the rat brain of a learned helplessness model of depression
BackgroundAlthough glutamate transmission via astrocytes has been proposed to contribute to the pathophysiology of depression, the precise mechanisms are unknown. Herein, we investigated the levels of glutamate transporter-1 (GLT-1) and glutamine synthetase (GS) of astrocytes in learned helplessness (LH) rats (an animal model of depression) and non-LH rats (an animal model of resilience).MethodsWe administered inescapable mild electric shock to rats and then discriminated the LH and non-LH rats by a post-shock test. Almost 55% of the rats acquired LH. We then measured the expressions of GLT-1 and GS in several brain regions of LH and non-LH rats by Western blot analysis.ResultsThe levels of GLT-1 and GS in the CA-1, CA-3, dentate gyrus (DG), medial prefrontal cortex (mPF), and nucleus accumbens (NAc) of the LH group were significantly higher than those of the control group. The GS levels in the amygdala of the LH rats were significantly decreased compared to the controls. There were significant differences in GLT-1 and GS levels between the non-LH and LH rats in the CA-1 and CA-3.ConclusionsThese results suggest that the LH rats experienced up-regulations of GLT-1 and GS in the CA-1, CA-3, DG, mPF, and NAc and a down-regulation of GS in the amygdala. It is possible that the effects of the GLT-1 and GS levels on astrocytes in the CA-1 and CA-3 are critical for the differentiation of resilience from vulnerability.
A retrospective clinical practice study comparing the usefulness of dual-orexin receptor antagonists and a melatonin receptor agonist in patients switching from long-term benzodiazepine receptor agonists
Study Objectives Although novel hypnotics have recently emerged, there are currently no data comparing the clinical potency of benzodiazepine receptor agonists (BZRAs) and novel hypnotics, or the effectiveness of different methods of switching between them. This study examined how novel hypnotics might help reduce BZRA use in real-world practice. Methods 289 patients with psychiatric disorders who took BZRAs for over 1 year before switching to either of 2 dual-orexin receptor antagonists (DORAs; suvorexant [SUV] or lemborexant [LEM]) or a melatonin receptor agonist (ramelteon [RMT]) were enrolled. We collected data on BZRAs at baseline and 3 months after commencement of SUV/LEM/RMT. Results Significant reductions in BZRAs were observed for all 3 agents: −4.10, −2.80, and −1.65 mg in diazepam-equivalent doses in the SUV, LEM, and RMT groups, respectively. Dose reduction was significantly greater in the DORA than the RMT group ( F = 15.053, P < .001). Within the DORA group, dose reduction was significantly greater in patients taking SUV than those taking LEM ( F = 4.337, P = .043). The switching success rate did not differ among the switching methods for any of the hypnotics. Conclusions The reduction rate of BZRAs achieved by the switch fell into their equivalent-potency range estimated from clinical trials. The results suggest that DORAs can replace approximately 1 tablet of a BZRA. The difference in dose reduction between DORAs and RMT reflected the greater sleeping potency of the DORAs, whereas that between SUV and LEM might have reflected patient backgrounds: patients taking LEM may have been more strongly dependent on BZRAs.
Decreased Serum Levels of Mature Brain-Derived Neurotrophic Factor (BDNF), but Not Its Precursor proBDNF, in Patients with Major Depressive Disorder
Meta-analyses have identified serum levels of brain-derived neurotrophic factor (BDNF) as a potential biomarker for major depressive disorder (MDD). However, at the time, commercially available human ELISA kits are unable to distinguish between proBDNF (precursor of BDNF) and mature BDNF because of limited BDNF antibody specificity. In this study, we examined whether serum levels of proBDNF, mature BDNF, and matrix metalloproteinase-9 (MMP-9), which converts proBDNF to mature BDNF, are altered in patients with MDD. Sixty-nine patients with MDD and 78 age- and gender-matched healthy subjects were enrolled. Patients were evaluated using 17 items on the Structured Interview Guide for the Hamilton Depression Rating Scale. Cognitive impairment was evaluated using the CogState battery. Serum levels of proBDNF, mature BDNF, and MMP-9 were measured using ELISA kits. Serum levels of mature BDNF in patients with MDD were significantly lower than those of normal controls. In contrast, there was no difference in the serum levels of proBDNF and MMP-9 between patients and normal controls. While neither proBDNF nor mature BDNF serum levels was associated with clinical variables, there were significant correlations between MMP-9 serum levels and the severity of depression, quality of life scores, and social function scores in patients. These findings suggest that mature BDNF may serve as a biomarker for MDD, and that MMP-9 may play a role in the pathophysiology of MDD. Further studies using larger sample sizes will be needed to investigate these results.
Mental health of youth athletes during the second year of the COVID‐19 pandemic in Japan: A three‐wave cross‐sectional study
Aim This study aimed to examine the mental health of Japanese youth athletes during the second year of the COVID‐19 pandemic and explore its associations with demographic and sport‐related factors. Methods Three cross‐sectional online surveys were conducted at a public high school in Japan in Spring 2021 (baseline; n = 1022), Fall 2021 (n = 1104), and Spring 2022 (n = 1066). Mental health was assessed using the Kessler‐6 (K6), Patient Health Questionnaire‐9 (PHQ‐9), and Generalized Anxiety Disorder‐7 (GAD‐7) scales. Participants were categorized as youth athletes (national‐level competitors [NC] and local‐level competitors [LC]) or nonathlete students (NAS). Logistic regression was used to identify the mental health risk factors. Results Compared to the baseline, youth athletes showed higher rates of poor mental health indicators in the second and third surveys. Among them, female athletes showed higher risks of depression and anxiety in both later surveys, whereas upper grade athletes had an increased risk of depression in the second survey. No consistent association was found between COVID‐19 infection history and mental health. Conclusion Japanese youth athletes showed poorer mental health indicators at later points in the second year of the pandemic. Female and upper grade athletes may require targeted mental health support. Continuous monitoring is essential during extended public health emergencies.
Neural substrates of treatment-resistant schizophrenia and the response to clozapine: A structural MRI study in a clinical setting
Predicting the responsiveness to clozapine among individuals with treatment-resistant schizophrenia (TRS) is difficult. A candidate predictor of clozapine response is the length of time prior to the introduction of clozapine treatment. The relationship between this measure and structural MRI findings has not been established. We compared the cortical-volume ratio between patients with TRS (n = 40 including 20 clozapine-treated patients) and non-TRS patients with schizophrenia (n = 64) and between each of these patient groups and healthy controls (HCs). We then investigated brain regions related to both responsiveness to clozapine and the duration between the TRS designation and the introduction of clozapine. The three-group comparison revealed that compared to the HCs, both patient groups had significantly lower cortical-volume ratios in widespread brain regions. However, there was no significant difference in the brain regions between the TRS and non-TRS groups: compared to the non-TRS group, the TRS group showed smaller volumes in a wider range of brain regions only at the uncorrected level. The correlational analysis of regions related to clozapine responsiveness did not identify any region that survived the correction for multiple comparisons. No relationship between any cortical region and the length of time prior to clozapine introduction was observed. Overall, these results failed to identify the cortical region responsible for the treatment response to clozapine. The lack of correlations between the length of time prior to clozapine introduction and cortical regions might have been derived by insufficient statistical power, thus necessitating further research.
Potentiation of Nerve Growth Factor-Induced Neurite Outgrowth by Fluvoxamine: Role of Sigma-1 Receptors, IP3 Receptors and Cellular Signaling Pathways
Selective serotonin reuptake inhibitors (SSRIs) have been widely used and are a major therapeutic advance in psychopharmacology. However, their pharmacology is quite heterogeneous. The SSRI fluvoxamine, with sigma-1 receptor agonism, is shown to potentiate nerve-growth factor (NGF)-induced neurite outgrowth in PC 12 cells. However, the precise cellular and molecular mechanisms underlying potentiation by fluvoxamine are not fully understood. In this study, we examined the roles of cellular signaling pathways in the potentiation of NGF-induced neurite outgrowth by fluvoxamine and sigma-1 receptor agonists. The effects of three SSRIs (fluvoxamine, sertraline, paroxetine) and three sigma-1 receptor agonists (SA4503, 4-phenyl-1-(4-phenylbutyl) piperidine (PPBP), and dehydroepiandrosterone (DHEA)-sulfate) on NGF-induced neurite outgrowth in PC12 cells were examined. Also examined were the effects of the sigma-1 receptor antagonist NE-100, inositol 1,4,5-triphosphate (IP(3)) receptor antagonist, and specific inhibitors of signaling pathways in the potentiation of NGF-induced neurite outgrowth by selective sigma-1 receptor agonist SA4503. Fluvoxamine (but not sertraline or paroxetine) and the sigma-1 receptor agonists SA4503, PPBP, and DHEA-sulfate significantly potentiated NGF-induced neurite outgrowth in PC12 cells in a concentration-dependent manner. The potentiation by fluvoxamine and the three sigma-1 receptor agonists was blocked by co-administration of the selective sigma-1 receptor antagonist NE-100, suggesting that sigma-1 receptors play a role in blocking the enhancement of NGF-induced neurite outgrowth. Moreover, the potentiation by SA4503 was blocked by co-administration of the IP(3) receptor antagonist xestospongin C. In addition, the specific inhibitors of phospholipase C (PLC-gamma), phosphatidylinositol 3-kinase (PI3K), p38MAPK, c-Jun N-terminal kinase (JNK), and the Ras/Raf/mitogen-activated protein kinase (MAPK) signaling pathways blocked the potentiation of NGF-induced neurite outgrowth by SA4503. These findings suggest that stimulation of sigma-1 receptors and subsequent interaction with IP(3) receptors, PLC-gamma, PI3K, p38MAPK, JNK, and the Ras/Raf/MAPK signaling pathways are involved in the mechanisms of action of sigma-1 receptor agonists such as fluvoxamine and SA4503.
Evaluating psychological distress associated with life events under the traumatic experience threshold in patients with major depressive and bipolar disorder
Patients with bipolar disorder (BD) and major depressive disorder (MDD) experience psychological distress associated with daily events that do not meet the threshold for traumatic experiences, referred to as event-related psychological distress (ERPD). Recently, we developed an assessment tool for ERPD, the ERPD-24. This tool considers four factors of ERPD: feelings of revenge, rumination, self-denial, and mental paralysis. We conducted a cross-sectional study between March 2021 and October 2022 to identify the differences and clinical features of ERPD among patients with MDD and BD and healthy subjects who did not experience traumatic events. Specifically, we assessed ERPD using the ERPD-24 and anxiety-related symptoms with the State-Trait Anxiety Inventory, Liebowitz Social Anxiety Scale, and anxious-depressive attack. Regarding the ERPD-24 scores among the groups, as the data did not rigorously follow the test of normality, the Kruskal–Wallis test was used to compare the differences among the groups, followed by the Dunn–Bonferroni adjusted post-hoc test. Non-remitted MDD patients and BD patients, regardless of remission/non-remission, presented more severe ERPD than healthy subjects. This study also demonstrated the relationships between all anxiety-related symptoms, including social phobia and anxious-depressive attack and ERPD, in both BD and MDD patients and in healthy subjects. In conclusion, patients with non-remitted MDD and with BD regardless of remission/non-remission experience severe ERPD related to anxiety-related symptoms.
Reevaluation of ADHD diagnoses in referral patients: A medical chart review in an advanced psychiatric hospital in Japan
Our study examined the diagnostic accuracy of ADHD among referral patients, revealing that 66% had confirmed ADHD while 24% had their diagnosis changed, primarily to bipolar disorder. These findings emphasize the need for comprehensive evaluation and multidisciplinary collaboration to ensure accurate diagnosis and effective treatment.