Suicidal ideation may be defined as any self-reported thoughts of engaging in suicide related behavior. The first chapter provides a comprehensive definition of the concept of suicidal ideation together with related epidemiological data and then reviews the major risk factors. The possible controversial role of early experiences of childhood abuse and neglect in the development of suicidal ideation are explored. The impact of universal, selective and indicated suicide prevention strategies in lowering suicide rates are analyzed as well. The authors of the remaining chapters of the book review the suicidal symptoms among veterans with Chronic PTSD; recent advances in antidepressant drugs research; hypotheses for the pathogens of the rarely occurring antimicrobial-induced mania and suicide; and suicide prevention methods using the internet.