Long-Term Treatment With Long-Acting Injectable Antipsychotic in Schizophrenia Patients With and Without Dopamine Supersensitivity Psychosis: A 6-Year Retrospective Comparative Study.

BACKGROUND: Dopamine supersensitivity psychosis (DSP) is an unstable psychotic state in patients with schizophrenia due to an upregulation of dopamine D2 receptors induced by antipsychotic medication. Long-acting antipsychotic injectable (LAI) could be advantageous for controlling the dopamine supersensitivity state, but it is not known if long-term treatment with LAI might ultimately lead to development or exacerbation of DSP. METHODS: The present study included 58 patients who had been treated with LAI for at least 3 years, with medical records for the 3 years before its introduction. Those records were used to classify patients as having DSP (n = 30, DSP group) or not (n = 28, non-DSP group). The effects of LAI treatments on the clinical course during the 3 years after the LAI introduction were compared between the 2 groups. RESULTS: Both groups demonstrated significant decreases in antipsychotic dosage (combined LAI and oral antipsychotics) and a significant improvement measured by clinical global impression-improvement. These indicators did not differ between them, suggesting similar efficacy of LAI for both groups. On average, the DSP group was treated with a higher dose of antipsychotics (1004.8 mg) before the LAI introduction compared with the non-DSP group but reduced them to within the standard dose range (662.0 mg) after the introduction of LAI. CONCLUSIONS: Our results indicated the effectiveness of LAI treatment for at least 3 years for patients with DSP, suggesting that this treatment strategy is unlikely to worsen DSP. The efficacy might be explained by the large decrease in the total antipsychotic dose with the introduction of LAI.

A preliminary genetic association study of GAD1 and GABAB receptor genes in patients with treatment-resistant schizophrenia.

BACKGROUND: GABAergic system dysfunction has been implicated in the etiology of schizophrenia and of cognitive impairments in particular. Patients with treatment-resistant schizophrenia (TRS) generally suffer from profound cognitive impairments in addition to severe positive symptoms, suggesting that GABA system dysfunction could be involved more closely in patients with TRS. METHODS AND RESULTS: In the present study, exome sequencing was conducted on fourteen TRS patients, whereby four SNPs were identified on GAD1, GABBR1 and GABBR2 genes. An association study for five SNPs including these 4 SNPs and rs3749034 on GAD1 as then performed among 357 patients with TRS, 682 non-TRS patients and 508 healthy controls (HC). The results revealed no significant differences in allelic and/or genetic distributions for any of the five SNPs. However, several subanalyses in comparisons between schizophrenia and HC groups, as well as between the three groups, showed nominal-level significance for rs3749034 on GAD1 and rs10985765/rs3750344 on GABBR2. In particular, in comparisons of female subjects, rigorous analysis for rs3749034 showed a statistical difference between the schizophrenia and HC groups and between the TRS and HC groups. CONCLUSIONS: Several positive results in subanalyses suggested that genetic vulnerability in the GABA system to schizophrenia or TRS could be affected by sex or sampling area, and overall, that rs3749034 on GAD1 and rs10985765 on GABBR2 could be related to TRS. In the present study, only a few SNPs were examined; it is possible that other important genetic variants in other regions of GABA-related genes were not captured in this preliminary study.

Characteristics of Early-Onset Dementia in Chiba Prefecture, Japan: A Multicenter Survey.

INTRODUCTION: Early-onset dementia (EOD), defined as dementia onset before the age of 65 years, is relatively rare, but its social impacts are significant. This study aimed to characterize the diagnosis and clinical and social status of EOD subjects in the 11 dementia centers in Chiba Prefecture, Japan. METHODS: A retrospective 1-year survey was conducted. Collected data included clinical diagnosis, age at onset, age at survey, neuropsychological test, family history, employment, and living status. RESULTS: We identified 208 EOD subjects, including 123 (59.4%), 24 (11.6%), 21 (10.1%), 17 (8.2%), and 10 (4.8%) with Alzheimer's disease (AD), vascular dementia, frontotemporal lobar degeneration (FTLD), dementia with Lewy bodies/Parkinson's disease dementia, and alcohol-related dementia, respectively. The Mini-Mental State Examination (MMSE) score <24 was observed in 50-75% of patients and was not correlated with disease duration. Twenty-four (16.4%) subjects had positive family history of EOD. EOD subjects were at risk of early retirement, and 133 subjects lived with their family, in whom 64 (30.8%) lived with their child. CONCLUSION: In dementia centers, AD, FTLD, and Lewy body dementia had relatively large proportion. Employment, economy, and social supports are urgently needed for EOD subjects and their family.

Genetic risks of schizophrenia identified in a matched case-control study.

It has been suggested that dopaminergic neurotransmission plays important roles for the psychotic symptoms and probably etiology of schizophrenia. In our recent preliminary study, we demonstrated that the specific allele combinations of dopamine-related functional single nucleotide polymorphisms (SNPs), rs10770141, rs4680, and rs1800497 could indicate risks for schizophrenia. The present validation study involved a total of 2542 individuals who were age- and sex-matched in a propensity score matching analysis, and the results supported the statistical significances of the proposed genetic risks described in our previous reports. The estimated odds ratios were 1.24 (95% CI 1.06-1.45, p < 0.001) for rs4680, 1.73 (95% CI 1.47-2.02, p < 0.0001) for rs1800497, and 1.79 (95% CI 1.35-2.36, p < 0.0001) for rs10770141. A significant relationship was also revealed among these three polymorphisms and schizophrenia, with corresponding coefficients (p < 0.0001). In this study, we also present a new scoring model for the identification of individuals with the disease risks. Using the cut-off value of 2, our model exhibited sensitivity for almost two-thirds of all of the schizophrenia patients: odds ratio 1.87, 95% CI 1.59-2.19, p < 0.0001. In conclusion, we identified significant associations of dopamine-related genetic combinations with schizophrenia. These findings suggest that some types of dopaminergic neurotransmission play important roles for development of schizophrenia, and this type of approach may also be applicable for other multifactorial diseases, providing a potent new risk predictor.

Efficacy and safety of lurasidone in acutely psychotic patients with schizophrenia: A 6-week, randomized, double-blind, placebo-controlled study.

AIM: The aim of this study was to evaluate the efficacy of lurasidone in acute schizophrenia in Japan and other countries. METHODS: Subjects (aged 18-74 years) diagnosed with schizophrenia were randomized to lurasidone 40 mg/day or placebo. The primary efficacy endpoint was change from baseline on the Positive and Negative Syndrome Scale (PANSS) total score at Week 6. Secondary efficacy assessments included the Clinical Global Impression-Severity Scale (CGI-S). Safety endpoints included adverse events, and laboratory and electrocardiogram parameters. RESULTS: A total of 483 subjects were randomized to lurasidone or placebo; 107 subjects were from Japan. Mean changes from baseline at Week 6 endpoint in PANSS total scores were -19.3 in the lurasidone group and -12.7 in the placebo group (treatment difference: P < 0.001, effect size = 0.41). Changes from baseline for Week 6 CGI-S scores were -1.0 for lurasidone and -0.7 for placebo (treatment difference: P < 0.001, effect size = 0.41). All-cause discontinuation during the 6-week, double-blind period was 19.4% for lurasidone and 25.4% for placebo, and discontinuation rates due to adverse event were 5.7% for lurasidone and 6.4% for placebo. The following common treatment-emergent adverse events occurred in more than 2% on lurasidone and at a rate at least twice that of the placebo group: akathisia (4.0%), dizziness (2.8%), somnolence (2.8%), abdominal discomfort (2.0%) and asthenia (2.0%). No significant changes in bodyweight or metabolic parameters were observed. CONCLUSION: Lurasidone 40 mg once daily dosing demonstrated efficacy in a patient population with acute schizophrenia, including subjects from Japan, and was generally safe and well-tolerated.

Perception of and anxiety about COVID-19 infection and risk behaviors for spreading infection: an international comparison.

BACKGROUND: To control the spread of the new SARS-CoV-2 infection's disease (COVID-19), appropriate precautionary behaviors by the public should be promoted. There are international differences in public cognitive and behavioral pattern, attitudes toward information sources, and anxiety about COVID-19. Information about these differences could increase understanding of the patterns of epidemic-related anxiety and behavior, and would help optimize future policies for preventing the next wave of the epidemic. METHODS: To examine between-country differences in perception, attitude, and precautionary behaviors toward COVID-19, we conducted a cross-sectional study using an online questionnaire survey. Participants were adults who had been registered in Cross Marketing Group Inc. and living in the UK, Spain, or Japan. A total of 8,000 people stratified by age were recruited on a first-come, first-serve basis. Knowledge of and anxiety about COVID-19, the frequency of access and perceived credibility of several information sources, and the frequency of each precautionary behavior were examined on March 27-28, 2020, in Japan and April 17-21, 2020, in the UK and Spain. RESULTS: Knowledge, anxiety, and the frequency of precautionary behaviors were higher in the UK and Spain than in Japan. Participants with infected acquaintances were more concerned about COVID-19. However, participants in the UK rarely wore a medical mask. Participants in the UK and Spain were more eager to obtain information about COVID-19 than those in Japan. Participants in Spain tended not to trust official information and to believe specialists' comments instead. CONCLUSION: The rapidity of the spread of COVID-19, cultural background, and recent political situations seemed to contribute to the international differences here.

Plasma Levels of Soluble Tumor Necrosis Factor Receptor 2 (sTNFR2) Are Associated with Hippocampal Volume and Cognitive Performance in Patients with Schizophrenia.

Background: An imbalance in the inflammatory tumor necrosis factor system, including soluble tumor necrosis factor receptor 2 (sTNFR2), may contribute to the pathophysiology of schizophrenia. Methods: We measured the plasma levels of sTNFR2 in 256 healthy controls and 250 patients with schizophrenia including antipsychotic drug-free patients and treatment-resistant patients. We also explored the possible association between plasma sTNFR2 levels and cognitive performance in healthy controls and patients with schizophrenia using the Wechsler Adult Intelligence Scale, Third Edition, the Wechsler Memory Scale-Revised, and the Rey Auditory Verbal Learning Test. An association between plasma sTNFR2 levels and hippocampal volume in controls and patients with schizophrenia was also investigated via MRI. Results: We found that the plasma levels of sTNFR2 were significantly higher in patients with schizophrenia, including both antipsychotic drug-free patients and treatment-resistant patients. We found a significant negative association between plasma sTNFR2 levels and cognitive performance in controls and patients with schizophrenia. Hippocampal volume was also negatively associated with plasma sTNFR2 levels in patients with schizophrenia. Conclusion: Together, these convergent data suggest a possible biological mechanism for schizophrenia, whereby increased sTNFR2 levels are associated with a smaller hippocampal volume and cognitive impairment.

First-episode psychosis in treatment-resistant schizophrenia: a cross-sectional study of a long-term follow-up cohort.

BACKGROUND: Approximately one-third of schizophrenia patients eventually develop treatment-resistant schizophrenia (TRS). Although the time course of TRS development varies from patient to patient, the details of these variations have not been clarified. The present study compared the duration of time required to achieve control of the first-episode psychosis (FEP) between patients who went on to develop TRS and those who did not, in order to determine whether a bifurcation point exists for the transition to TRS. METHODS: The present study included 271 schizophrenia patients. Based on the clinical assessment, each patient was assigned to a TRS (n = 79) or Non-TRS group (n = 182). Clinical factors relating to FEP treatment such as the duration of initial hospital admission and the degree of improvement were retrospectively identified. RESULTS: There was no significant difference in the duration of initial hospital admission (defined as the time from treatment introduction to successful discharge) between the two groups (mean of 87.9 days for TRS vs. 53.3 days for Non-TRS). The degree of improvement during initial hospital admission of the TRS group was significantly lower than that of the Non-TRS group (Global Assessment of Functioning (GAF) of 50 points for TRS vs. 61 points for Non-TRS). Approximately half of the TRS patients showed an acute onset pattern and longer hospital admission (mean 169 days) for their FEP. The other half of TRS patients needed no hospital admission, indicating an insidious onset pattern with no clear psychotic episode and treatment introduction without hospital admission. CONCLUSIONS: Future TRS patients can have difficulty in improvement during their FEP. There appear to be two distinct patterns for the development of TRS. One pattern is characterized by refractory positive symptoms and a longer period to control the first psychosis; the other shows latent or insidious onset and poor response to the initial treatment.

Antipsychotic-Induced Dopamine Supersensitivity Psychosis: Pharmacology, Criteria, and Therapy.

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.

Altered serum level of matrix metalloproteinase-9 and its association with decision-making in eating disorders.

AIM: The aims of this study were to determine whether the serum levels of precursor brain-derived neurotrophic factor (proBDNF), mature BDNF (mBDNF), and matrix metalloproteinase-9 (MMP-9) are altered in patients with eating disorders (ED), including anorexia nervosa (AN) and bulimia nervosa (BN), and to explore whether those levels are associated with decision-making abilities. METHODS: Nineteen women with AN, 28 women with BN, and 22 age-matched healthy control women (HC) were enrolled in the current study. All participants had their decision-making abilities assessed using the Iowa Gambling Task (IGT). Their eating-related pathophysiology and depressive/anxiety symptoms were also evaluated. RESULTS: The MMP-9 level in AN was significantly lower than that in either BN or HC, but the serum levels of proBDNF and mBDNF did not differ among the three groups. Investigation of the serum levels of proBDNF and MMP-9 in patients with ED and controls revealed a significant correlation between them. In the BN, there were positive correlations between mBDNF level and IGT performance and also between MMP-9 level and IGT performance, but these correlations did not occur in AN. The MMP-9 level was positively associated with the Symptom Scale, one of the subscales of the Bulimic Investigatory Test, Edinburgh, only in AN. CONCLUSION: These results suggest that the serum level of MMP-9 plays a role in the pathophysiology of AN, and both the serum levels of mBDNF and MMP-9 may be associated with decision-making abilities in patients with BN.

Relationship between symptom dimensions and white matter alterations in obsessive-compulsive disorder.

OBJECTIVE: To investigate the relationship between the severities of symptom dimensions in obsessive-compulsive disorder (OCD) and white matter alterations. METHODS: We applied tract-based spatial statistics for diffusion tensor imaging (DTI) acquired by 3T magnetic resonance imaging. First, we compared fractional anisotropy (FA) between 20 OCD patients and 30 healthy controls (HC). Then, applying whole brain analysis, we searched the brain regions showing correlations between the severities of symptom dimensions assessed by Obsessive-Compulsive Inventory-Revised and FA in all participants. Finally, we calculated the correlations between the six symptom dimensions and multiple DTI measures [FA, axial diffusivity (AD), radial diffusivity (RD), mean diffusivity (MD)] in a region-of-interest (ROI) analysis and explored the differences between OCD patients and HC. RESULTS: There were no between-group differences in FA or brain region correlations between the severities of symptom dimensions and FA in any of the participants. ROI analysis revealed negative correlations between checking severity and left inferior frontal gyrus white matter and left middle temporal gyrus white matter and a positive correlation between ordering severity and right precuneus in FA in OCD compared with HC. We also found negative correlations between ordering severity and right precuneus in RD, between obsessing severities and right supramarginal gyrus in AD and MD, and between hoarding severity and right insular gyrus in AD. CONCLUSION: Our study supported the hypothesis that the severities of respective symptom dimensions are associated with different patterns of white matter alterations.

Cognitive Behavioral Therapy for Patients with Social Anxiety Disorder Who Remain Symptomatic following Antidepressant Treatment: A Randomized, Assessor-Blinded, Controlled Trial.

BACKGROUND: Although antidepressants are still a commonly used treatment for social anxiety disorder (SAD), a significant proportion of patients fail to remit following antidepressants. However, no standard approach has been established for managing such patients. This study aimed to examine the effectiveness of cognitive behavioral therapy (CBT) as an adjunct to usual care (UC) compared with UC alone in SAD patients who remain symptomatic following antidepressant treatment. METHODS: This was a prospective randomized open-blinded end-point study with two parallel groups (CBT + UC, and UC alone, both for 16 weeks) conducted from June 2012 to March 2014. SAD patients who remain symptomatic following antidepressant treatment were recruited, and a total sample size of 42 was set based on pilot results. RESULTS: Patients were randomly allocated to CBT + UC (n = 21) or UC alone (n = 21). After 16 weeks, adjusted mean reduction in the Liebowitz Social Anxiety Scale from baseline for CBT + UC and UC alone was -40.87 and 0.68, respectively; the between-group difference was -41.55 (-53.68 to -29.42, p < 0.0001). Response rates were 85.7 and 10.0% for CBT + UC and UC alone, respectively (p < 0.0001). The corresponding remission rates were 47.6 and 0.0%, respectively (p = 0.0005). Significant differences were also found in favor of CBT + UC for social anxiety symptoms, depressive symptoms, and functional impairment. CONCLUSIONS: Our results suggest that in SAD patients who have been ineffectively treated with antidepressants, CBT is an effective treatment adjunct to UC over 16 weeks in reducing social anxiety and related symptoms.

Effect of mirtazapine versus selective serotonin reuptake inhibitors on benzodiazepine use in patients with major depressive disorder: a pragmatic, multicenter, open-label, randomized, active-controlled, 24-week trial.

BACKGROUND: This study aimed to evaluate whether selecting mirtazapine as the first choice for current depressive episode instead of selective serotonin reuptake inhibitors (SSRIs) reduces benzodiazepine use in patients with major depressive disorder (MDD). We concurrently examined the relationship between clinical responses and serum mature brain-derived neurotrophic factor (BDNF) and its precursor, proBDNF. METHODS: We conducted an open-label randomized trial in routine psychiatric practice settings. Seventy-seven MDD outpatients were randomly assigned to the mirtazapine or predetermined SSRIs groups, and investigators arbitrarily selected sertraline or paroxetine. The primary outcome was the proportion of benzodiazepine users at weeks 6, 12, and 24 between the groups. We defined patients showing a ≥50 % reduction in Hamilton depression rating scale (HDRS) scores from baseline as responders. Blood samples were collected at baseline, weeks 6, 12, and 24. RESULTS: Sixty-five patients prescribed benzodiazepines from prescription day 1 were analyzed for the primary outcome. The percentage of benzodiazepine users was significantly lower in the mirtazapine than in the SSRIs group at weeks 6, 12, and 24 (21.4 vs. 81.8 %; 11.1 vs. 85.7 %, both P < 0.001; and 12.5 vs. 81.8 %, P = 0.0011, respectively). No between-group difference was observed in HDRS score changes. Serum proBDNF levels were significantly decreased (χ2 = 8.5, df = 3, P = 0.036) and serum mature BDNF levels were temporarily significantly decreased (F = 3.5, df = 2.4, P = 0.027) in the responders of both groups at week 24. CONCLUSION: This study demonstrated mirtazapine as the first-choice antidepressant for current depressive episodes may reduce benzodiazepine use in patients with MDD. Trial registration UMIN000004144. Registered 2nd September 2010. The date of enrolment of the first participant to the trial was 24th August 2010. This study was retrospectively registered 9 days after the first participant was enrolled.

Repetitive Transcranial Magnetic Stimulation Changes Cerebral Oxygenation on the Left Dorsolateral Prefrontal Cortex in Bulimia Nervosa: A Near-Infrared Spectroscopy Pilot Study.

Previous studies showed that food craving in eating disorders can be weakened with high-frequency repetitive transcranial magnetic stimulation (rTMS) on the left dorsolateral prefrontal cortex (DLPFC). The aims of this study were to assess cerebral oxygenation change induced with rTMS and to assess the short-term impact of rTMS on food craving and other bulimic symptoms in patients with bulimia nervosa (BN). Eight women diagnosed with BN according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria participated in this study. We measured haemoglobin concentration changes in the DLPFC with near-infrared spectroscopy during cognitive tasks measuring self-regulatory control in response to food photo stimuli, both at baseline and after a single session of rTMS. Subjective ratings for food cravings demonstrated significant reduction. A significant decrease in cerebral oxygenation of the left DLPFC was also observed after a single session of rTMS. Measurement with NIRS after rTMS intervention may be applicable for discussing the mechanisms underlying rTMS modulation in patients with BN.

Characteristics of female mentally disordered offenders culpable under the new legislation in Japan: A gender comparison study.

BACKGROUND: Although a substantial increase in the number of female offenders has drawn interest towards understanding their unique characteristics, few studies have investigated the characteristics of female mentally disordered offenders in Japan and none since the legislation enacted in 2005 in Japan, which provided for special services for them. AIMS: The aim of this study is to identify those characteristics of people detained under this legislation, which distinguish the women from the men and may indicate special needs among the women. METHODS: A retrospective records-based study of all patients admitted to one secure unit in the 8 years since its opening in July 2005 until a census date of 31 October 2013. RESULTS: Thirty-six (15%) of the patients were women. Marriage, mood disorders, past suicide attempts and homicide were more common among the women than the men. Six of the female offender-patients had committed filicides, of which four were infanticides. CONCLUSION: There appears to be a particularly vulnerable sub-group of women with severe mood disorders, a history of serious suicide attempts and young children at risk of harming those children. Our sample was small and from a single unit so, given the potential importance of improving understanding of who is at risk in such circumstances, extending our study nationally seems indicated.

Increased serum levels of serine enantiomers in patients with depression.

OBJECTIVE: Glutamatergic neurotransmission via the N-methyl-d-aspartate (NMDA) receptor is integral to the pathophysiology of depression. This study was performed to examine whether amino acids related to NMDA receptor neurotransmission are altered in the serum of patients with depression. METHOD: We measured the serum levels of d-serine, l-serine, glycine, glutamate and glutamine in patients with depression (n=70), and age-matched healthy subjects (n=78). RESULTS: Serum levels of d-serine and l-serine in patients with depression were significantly higher than those of healthy controls (p<0.001). In contrast, serum levels of glycine, glutamate and glutamine did not differ between the two groups. Interestingly, the ratio of l-serine to glycine in patients was significantly higher than that of healthy controls (p<0.001). CONCLUSION: This study suggests that serine enantiomers may be peripheral biomarkers for depression, and that abnormality in the d-serine-l-serine-glycine cycle plays a role in the pathophysiology of depression.

Treatment of puberty trichotillomania with low-dose aripiprazole.

The present case is of a 14-year-old female with trichotillomania (TTM) that was treated with a low dose of aripiprazole (ARP) 1.5 mg/day. To our knowledge, this is the first published report to show an improvement of pubertal TTM using an ultra-low dose of ARP. In this case, a 50-mg fluvoxamine monotherapy for 2 years and a subsequent 4-month comprehensive cognitive behavioral therapy (CBT) monotherapy did not improve her hair-pulling symptoms. However, the treatment with a low-dose ARP of 1.5 mg/day dramatically improved her TTM symptoms without extrapyramidal symptoms. In this regard, low-dose ARP treatment for TTM might be a safe alternative to antidepressants, which carry the risk of agitation with suicidal ideation in adolescents.

Alterations of Dopamine D2 Receptors and Related Receptor-Interacting Proteins in Schizophrenia: The Pivotal Position of Dopamine Supersensitivity Psychosis in Treatment-Resistant Schizophrenia.

Although the dopamine D2 receptor (DRD2) has been a main target of antipsychotic pharmacotherapy for the treatment of schizophrenia, the standard treatment does not offer sufficient relief of symptoms to 20%-30% of patients suffering from this disorder. Moreover, over 80% of patients experience relapsed psychotic episodes within five years following treatment initiation. These data strongly suggest that the continuous blockade of DRD2 by antipsychotic(s) could eventually fail to control the psychosis in some point during long-term treatment, even if such treatment has successfully provided symptomatic improvement for the first-episode psychosis, or stability for the subsequent chronic stage. Dopamine supersensitivity psychosis (DSP) is historically known as a by-product of antipsychotic treatment in the manner of tardive dyskinesia or transient rebound psychosis. Numerous data in psychopharmacological studies suggest that the up-regulation of DRD2, caused by antipsychotic(s), is likely the mechanism underlying the development of the dopamine supersensitivity state. However, regardless of evolving notions of dopamine signaling, particularly dopamine release, signal transduction, and receptor recycling, most of this research has been conducted and discussed from the standpoint of disease etiology or action mechanism of the antipsychotic, not of DSP. Hence, the mechanism of the DRD2 up-regulation or mechanism evoking clinical DSP, both of which are caused by pharmacotherapy, remains unknown. Once patients experience a DSP episode, they become increasingly difficult to treat. Light was recently shed on a new aspect of DSP as a treatment-resistant factor. Clarification of the detailed mechanism of DSP is therefore crucial, and a preventive treatment strategy for DSP or treatment-resistant schizophrenia is urgently needed.

A Comparison of Manifestations and Impact of Reassurance Seeking among Japanese Individuals with OCD and Depression.

BACKGROUND: One of the most common interpersonal reactions to threat and anxiety is to seek reassurance from a trusted person. The Reassurance Seeking Questionnaire (ReSQ) measures several key aspects of reassurance seeking behaviour, including frequency, trust of sources, intensity, carefulness, and the emotional consequences of reassurance seeking. AIMS: The current study compares patterns and consequences of reassurance seeking in obsessive-compulsive disorder (OCD) and depression. METHOD: ReSQ scores were compared for three groups: 32 individuals with OCD, 17 individuals with depression, and 24 healthy comparison participants. RESULTS: We found that individuals with OCD tended to seek reassurance more intensely and employ self-reassurance more frequently than individuals with depression or healthy participants, and that if reassurance was not provided, they tended to feel a greater urge to seek additional reassurance. CONCLUSIONS: This study is the first to quantitatively elucidate differences in reassurance seeking between OCD and depression.

Effects of sodium benzoate on pre-pulse inhibition deficits and hyperlocomotion in mice after administration of phencyclidine.

OBJECTIVE: A recent clinical study demonstrated that sodium benzoate (SB), a prototype competitive d-amino acid oxidase inhibitor, was effective in the treatment of several symptoms, such as positive and negative symptoms, and cognitive impairment in medicated patients with schizophrenia. The objective of the study was to examine the effects of SB on behavioural abnormalities such as pre-pulse inhibition (PPI) deficits and hyperlocomotion in mice after a single administration of the N-methyl-D-aspartate (NMDA) receptor antagonist, phencyclidine (PCP). METHODS: The effects of SB on behavioural abnormalities (PPI deficits and hyperlocomotion) in mice after PCP administration were examined. Furthermore, effects of SB on tissue levels of amino acids were also examined. RESULTS: A single oral dose of SB (100, 300, or 1000 mg/kg) attenuated PPI deficits in mice after administration of PCP (3.0 mg/kg, s.c.) in a dose-dependent manner. In contrast, L-701,324 (10 mg/kg), an antagonist at the glycine site of the NMDA receptor, did not affect the effect of SB (1000 mg/kg) on PCP-induced PPI deficits. Furthermore, a single oral dose of SB (1000 mg/kg) significantly attenuated the hyperlocomotion in mice after administration of PCP (3.0 mg/kg, s.c.). However, a single oral dose of SB (1000 mg/kg) caused no changes to D-serine levels in plasma or in the frontal cortex, hippocampus, and striatum of these animals. CONCLUSION: This study suggests that SB induced antipsychotic effects in the PCP model of schizophrenia, although it did not increase D-serine levels in the brain.