Distinguishing suicide attempts from nonsuicidal self-harming behaviors.

We would like to applaud Dr. Nock for his timely, thoughtful, and articulate piece addressing the issue of presumed causality in youth suicide. We are also encouraged to see the articles appearing in the same issue of the Journal addressing the issues of bullying and alcohol misuse, as they are good examples of the type of quality research that can take the field beyond the emotional drivers for ‘‘understanding’’ youth suicide to better help us consider the complex causal composites of those behaviors so that we may rationally and objectively develop and test appropriate interventions to address this important public health need. Kudos notwithstanding, we are concerned that Dr. Nock neglected to address a vital aspect of youth suicide research in his otherwise excellent overview. That is the differentiation of suicide attempts (self-harm with the intent to die) from nonsuicidal self-harm behaviors. In the research literature, suicide attempt is often used as an umbrella term referring to self-harm behaviors occurring with or without suicidal intent. In the International Classification of Diseases, there is no distinction between nonsuicidal self-inflicted injuries and suicide attempts, with both cases coded as ‘‘intentional selfharm.’’ This aggregation of suicidal and nonsuicidal self-harm behaviors may actually obfuscate important causal relationships and thus may confuse interventional responses. It may also explain why there are such differences in sex rates or why studies such as the one by Klomek et al. find male and female differences in outcomes (e.g., are all suicide attempts in young female subjects really suicide attempts, are a substantial proportion of them actually nonsuicidal self-harm attempts?). Importantly, some recent research suggests that once such differentiation occurs, unique populations may emerge. We would like to see data on self-harm in young people collected, coded, and presented on the basis of the suicidal intent associated with the action. For example, using the terms suicidal self-harm when discussing suicide attempts and nonsuicidal self-harm when discussing other self-injurious behaviors occurring in the absence of suicidal intent would clarify the discourse around self-harm. Although this could open the door to some degree of interpretation, including potential historical differences in these categories over the life span of an individual, we think that these concerns would be well outweighed by the greater clarity provided by this vital distinction. Determining the differences between populations who engage in suicidal and nonsuicidal self-harm will help us make better sense of this complex domain and may result in the implementation of better adapted prevention strategies and delivery of more appropriate interventions to these groups.