Kelly Posner, Beth Brodsky, Kseniya Yershova, Jacqueline Buchanan, and John Mann
Consistent definitions of suicide and the full spectrum of suicidal phenomena are critical for suicide prevention and the advancement of knowledge across disciplines. Historically, the absences of conceptual clarity, uniform nomenclature, and standardized assessment methods have blended definitional boundaries between suicidal and nonsuicidal self-injurious behavior and suicidal ideation. The range of suicidal behavior was restricted to suicide and suicide attempts, and it did not include or distinguish between these and other types of suicidal behavior now known to be related to suicide. The most significant advancement in the classification of suicide includes partial or “nonzero” intent to die as both a sufficient and necessary criterion, which may be stated or inferred from the self-injury lethality or surrounding circumstances. These key developments should inform the adoption of an internationally accepted diagnostic system for naming and classifying suicidal behavior and ideation, which in turn should guide medical, legal, and scientific communication.
Jennifer J. Muehlenkamp
Suicide and nonsuicidal self-injury (NSSI) continue to be significant behavioral health concerns for adolescents and adults. Research is progressing with regard to understanding these two behaviors and the connection they share. However, a number of questions remain. Complicating current understanding of either behavior is the high co-occurrence between suicide and NSSI, the degree of risk correlates shared, and blurred definitional guidelines. This chapter provides a comprehensive review of the existing literature in an effort to synthesize the current knowledge about what constitutes NSSI versus suicidal behavior, and how the two behaviors truly differ from each other across a number of descriptive features, demographic characteristics, and psychosocial variables. The chapter concludes with a discussion of the relationship between NSSI and suicide attempts, offering directions for future research in this area.