Preface

Psychosis has historically been the central problem of psychiatry because it harms both reason and emotion, even sometimes personality itself, and, whether rapidly or gradually, destroys the productive life of people. It is also intriguing for researchers due to the variety of subjective symptoms, which are enigmatic and provoke artistic imaginations.

Schizophrenia, the representative syndrome of psychotic disorders, still remains the hardest subject for psychiatric practice, although recently said to be becoming milder in the clinical features. Pathogenesis of schizophrenia is not yet solved and thus antipsychotic medications are not curative but rather symptomatic therapies.

This volume presents current research for the elucidation of psychosis in three different aspects: phenomenological, which relates to the philosophical or conceptual basis of psychosis; psychopathological, which relates to clinical manifestations of psychosis; and pathophysiological, which relates to the scientific pursuit for the mechanism of psychosis.

Chapter 1, "Understanding / Psychosis," deals with the very basis of diagnosis of psychosis differentiated from neurosis or psychogenic symptoms, namely, un-understandability as the impossibility of understanding in Japers' sense.

Chapter 2, "The Axiological Structure in Psychosis," presents the phenomenologicalexistential analysis of psychosis and suggests its therapeutic implications.

Chapter 3, "Clinical Staging in Schizophrenia Spectrum Disorders," summarizes the state-of-the-art knowledge of clinical staging in schizophrenia spectrum disorders.

Chapter 4, "The Many Faces of Negative Symptoms in Schizophrenia," addresses recent advances regarding the concepts, definitions, and classifications of negative symptoms of schizophrenia and their etiological model.

Chapter 5, "Role of Immunity in Pathogenesis of Psychosis," reviews the immuneinflammatory theory of schizophrenia and its clinical implications.

Chapter 6, "The Role of Epigenetics in Psychosis," deals with the possible significance of epigenetic dysregulation in the pathogenesis of schizophrenia.

Finally, Chapter 7, "DNA Methyltransferases and Schizophrenia: Current Status," reviews the dysregulation of DNA methyltransferases in schizophrenia.

This book provides readers with novel insight into psychosis and will help to advance research in the field.

> **Kenjiro Fukao, M.D., Ph.D.** Tezukayama Gakuin University, Osaka, Japan
