Masaya Tayama

Internet addiction and self-evaluated attention-deficit hyperactivity disorder traits among Japanese college students.

Internet addiction (IA), also referred to as Internet use disorder, is a serious problem all over the world, especially in Asian countries. Severe IA in students may be linked to academic failure, attention‐deficit hyperactivity disorder (ADHD), and forms of social withdrawal, such as hikikomori. In this study, we performed a survey to investigate the relation between IA and ADHD symptoms among college students.

Internet addiction and self-evaluated ADHD traits among Japanese college students

Internet addiction (IA), also referred to as Internet use disorder, is a serious problem all over the world, especially in Asian countries. Severe IA in students may be linked to academic failure, attention‐deficit hyperactivity disorder (ADHD), and forms of social withdrawal, such as hikikomori. In this study, we performed a survey to investigate the relation between IA and ADHD symptoms among college students.

The Study of Cognitive Characteristics in Asperger’s Disorder by Using a Modified Prisoner’s Dilemma Game with a Variable Payoff Matrix

Individuals with Asperger’s Disorder (ASP) have difficulties in social reciprocity and in providing appropriate cooperative behavior. The Prisoner’s Dilemma (PD) is a well-known model in game theory that illustrates the paradoxical disposition of interaction between two individuals with opposing interests, and may be a useful tool in the diagnosis of ASP in early childhood. In this study, we investigated the cognitive characteristics of ASP by using a modified PD game. The subjects were 29 individuals with ASP and 28 age- and IQ-matched controls. In the PD game, each of two players has two cards: card 1 represents cooperation and card 2 betrayal. The score each player obtains is decided according to a 2 x 2 payoff matrix and depends on the combination of their selections. The P-score (“P” for punishment) is defined as the score that is given when they both select betrayal. Comparing the two groups, the mean P-score at the end of the game and the mean total score were significantly higher in the ASP group, while the rate of selection of cooperative choice in both groups did not differ significantly. The classification of the shape of the graph according to fluctuation of the P-score revealed that in the ASP group only 2 cases (6.9%) showed continuous decrease of P-score compared to 8 control cases (28.6%) demonstrating similar results. However, the reasons were thought to be different: ASP subjects presumably selected card 2 because of a preference for the number itself, whereas control subjects preferentially chose this card to enhance their chance of winning the competition. It is often difficult to diagnose ASP in the young especially when they lack the distinctive clinical features of ASD in early childhood. Given the limited number of objective tools to evaluate the cognitive characteristics of ASP subjects, the PD game might be a useful diagnostic support tool for ASP.

Prevalence rate of Internet addiction among Japanese college students: Two cross-sectional studies and reconsideration of cut-off points of Young's Internet Addiction Test in Japan: Prevalence rate of Internet addiction

Due to variation in estimates of the prevalence of Internet addiction (IA) in prior research, we conducted two cross‐sectional studies over 2 years investigating the prevalence rate of IA in college students in Japan and reconsidered appropriate cut‐off points of a self‐rating scale to screen possible IA.

Psychiatric Consultations at an Emergency Department in a Metropolitan University Hospital in Northern Japan

Many patients with mental disorders visit emergency departments (EDs). However, the majority of these patients do not receive psychiatric assessment. In the present study, we investigated the detailed proportion of patients with mental disorders visiting an urban ED in the largest northern city in Japan. A retrospective chart review study was performed at a University Hospital from January 2012 to December 2015. The reasons for psychiatric consultations made by ED staff, and the primary psychiatric diagnoses were investigated. Among all living patients, 20% of them received consultations. The most common reason for consultation was suicide attempt followed by agitation or insomnia. Of all diagnoses, organic mental disorder was the most frequent and the mean age was significantly higher than the other diagnostic groups. Our study indicated that the frequency of psychiatric consultation was high. This indicates the high demand for mental health services at the ED. A thorough psychiatric assessment can provide adequate psychiatric services to acute patients; thereby possibly preventing suicide attempters from later actually dying by suicide.

Antipsychotics promote GABAergic interneuron genesis in the adult rat brain: Role of heat-shock protein production

Current antipsychotics reduce positive symptoms and reverse negative symptoms in conjunction with cognitive behavioral issues with the goal of restoring impaired occupational and social functioning. However, limited information is available on their influence on gliogenesis or their neurogenic properties in adult schizophrenia brains, particularly on GABAergic interneuron production. In the present study, we used young adult subventricular zone (SVZ)-derived progenitor cells expressing proteoglycan NG2 cultures to examine the oligodendrocyte and GABAergic interneuron genesis effects of several kinds of antipsychotics on changes in differentiation function induced by exposure to the NMDA receptor antagonist MK-801. We herein demonstrated that antipsychotics promoted or restored changes in the oligodendrocyte/GABAergic interneuron differentiation functions of NG2(+) cells induced by the exposure to MK-801, which was considered to be one of the drug-induced schizophrenia model. We also demonstrated that antipsychotics restored heat-shock protein (HSP) production in NG2(+) cells with differentiation impairment. The antipsychotics olanzapine, aripiprazole, and blonanserin, but not haloperidol increased HSP90 levels, which were reduced by the exposure to MK-801. Our results showed that antipsychotics, particularly those recently synthesized, exerted similar GABAergic interneuron genesis effects on NG2(+) neuronal/glial progenitor cells in the adult rat brain by increasing cellular HSP production, and also suggest that HSP90 may play a crucial role in the pathophysiology of schizophrenia and is a key target for next drug development.

PS198. Pathological analysis of refractory depression using fetal alcohol and adolescent corticosterone double stress model

Objectives: The purpose of this study is to investigate the alterations of the hypothalamic-pituitary-adrenal axis hormones, especially salivary cortisol and dehydroepiandrosterone (DHEA) in perinatal depression. Methods: 44 patients with depression and 217 normal subjects in perinatal period were included in this study. Edinburgh Postnatal Depression Scale(EPDS) and Beck Depression Inventory II(BDI-II) were performed. The subjects below 10 points of EPDS score or below 13 points of BDI-II score were classified to normal subjects. Among the subjects more than 11 points of EPDS score or more than 14 points of BDI-II score were diagnosed depression by DSM-IV TR by psychiatrists. All subjects were to collect their saliva in each 4 collecting tubes, immediately upon awakening(IA), 30 minutes after awakening(30A), 60 minutes after awakening(60A) and before bedtime(BB). Results: The number of subjects in antenatal period were 103, and antenatal depression(AD) patients were 21, antenatal normal(AN) subjects were 82. The number of subjects in postnatal period were 114, and postnatal depression(PD) patients were 23, postnatal normal(PN) subjects were 91. Salivary cortisol levels in subjects with AD collected IA, 30A and 60A were lower than with AN subjects significantly except BB. Salivary cortisol levels in subjects with PD collected 60A only were lower than with PN subjects significantly. Salivary DHEA levels in subjects with both AD and PD were lower than with normal subjects significantly. Also cortisol/DHEA ratio(F/D ratio) in subjects with both AD and PD were much higher than with normal subjects significantly. Conclusions: These results suggest that the blunted response was shown in AD, and the characteristics between AD and PD are different. Also the differences of salivary DHEA levels and F/D ratio between subjects with PD and normal subjects are suggested the one of the key points of difference among both groups. PS197 Low level of perineuronal nets in the medial prefrontal cortex predicts vulnerability to stress Na Chen,1 Die Hu,1 Lin Lu,1,2,3 Jie Shi 1 1National Institute on Drug Dependence, Peking University, Beijing, China; 2Institute of Mental Health/Peking University Sixth Hospital and Key Laboratory of Mental Health, Ministry of Health, Beijing, China; 3Peking-Tsinghua Center for Life Sciences and PKU-IDG/ McGovern Institute for Brain Research; Abstract Perineuronal nets (PNNs) are extracellular matrix structures enwrapping parvalbumin-positive γ-aminobutyric acid (GABA)ergic interneurons which are crucial for modulating anxiety and depressive-like behaviors. Perineuronal nets have recently been implicated in experience-dependent neuroplastic changes in central nervous system, but it is poorly understood that whether PNNs modulates the neural maladaptation after repeated exposure to stress. We found that adolescent rats with vulnerability to chronic unpredictable mild stress (CUMS) showed decreased level of PNNs, tenascin-R and aggrecan in the medial prefrontal cortex (mPFC). Degradation of PNNs in mPFC produced vulnerability to stress in adult rats. Elevating PNNs in the mPFC through environment enrichment prevented CUMS-induced depressive and anxiety-like behavior. Fluoxetine reversed the stress vulnerability in adolescent rats and increased PNNs levels. Lower level of PNNs rendered GABAergic neurons susceptible to CUMS, manifesting as decreases in expression of glutamic acid decarboxylase 67 (GAD 67) and frequency and amplitude of inhibitory postsynaptic current (IPSC) after CUMS. The organization of PNNs coincided with the developmental switch in stress vulnerability to resilience. These findings indicate a role of PNNs in mPFC in predicting and modulating vulnerability to stressinduced depressive-like behavior, and the effect may be produced though regulating GABAergic functions.