Fri. Oct 11, 2019 10:30 AM - 12:10 PM Room 13 (501)

Organizer / Chair: Kazuyuki NAKAGOME (National Center of Neurology and Psychiatry, Japan), Co-chair: Akira MONJI (Department of Psychiatry, Saga University Faculty of Medicine, Japan), Discussants: ‌Mitsuhiko YAMADA (Department of Neuropsychopharmacology, National Institute of Mental Health, National Center of Neurology and Psychiatry, Japan), Shinji TAKAHASHI (Taisho Pharmaceutical Co., Ltd., Japan)

Schizophrenia is a fairly common and devastating mental illness characterized by positive and negative symptoms, with cognitive dysfunction. Patients with schizophrenia are usually treated with antipsychotic medication. However, 10-30% of schizophrenic patients are treatment resistant, and the pharmaceutical industry still considers schizophrenia as an attractive target for drug design and there are many novel agents in early development. Recently, some abnormalities in neural circuits and brain networks are proposed as objective biomarkers for positive symptoms, such as hallucinations or delusions. These biomarkers could be used in different stages of clinical drug development (mechanism of action, target engagement, use as diagnostic test, enrichment of study populations, stratification for subgroups, safety and efficacy markers, etc.). In addition, these abnormalities can also be studied in animal models to facilitate the discovery of new targets and drug candidates. The purpose of this symposium is to discuss the novel strategy to treat hallucinations and delusions in schizophrenia, based on the findings obtained from translational researches using advanced techniques to study neural circuits and brain networks. Potential use of the biomarkers in drug development would also be discussed. The first speaker will review the recent advancement of connectivity studies of hallucinations and delusions in schizophrenia. The topic includes salience-associated networks underlying psychosis and structural and functional connectivity associated with abnormal conservatism bias and the jumping to conclusions bias in patients. It is reported that 60-90% of patients with schizophrenia suffer from auditory hallucinations. It is hypothesized that auditory-verbal hallucinations are caused by an inner-speech abnormality. The second speaker will introduce the project exploring the causes of auditory-verbal hallucinations with a novel electrophysiological marker of inner-speech. On the other hand, patients with schizophrenia have been hypothesized to have a functional impairment in filtering irrelevant sensory information, which may result in hallucinations and delusions. The third speaker will review possible association between the auditory gating deficits and positive symptoms, focusing on the abnormalities in spontaneous gamma activity in schizophrenia. Finally, the fourth speaker will review the abnormal thalamocortical networks in schizophrenia. The topic includes the translational research using a novel mouse model to study roles of parvalbumin-expressing GABAergic neurons in the pathophysiology of schizophrenia. We hope that this symposium will help the audience to understand the recent advancements of translational researches focusing on abnormalities in neural circuits and brain networks to treat hallucinations and delusions in schizophrenia.