A nurse in an emergency department is caring for an adolescent following a suicide attempt. After reviewing the client's history, the nurse should determine that which of the following is the priority risk factor for suicide completion?

A. Previous suicide attempt: A prior suicide attempt is the strongest predictor of future suicide completion, as it demonstrates both intent and access to means. It is considered a high-risk red flag in adolescents. B. Loss of a parent: While parental loss is a significant psychosocial stressor, it is not as strong a predictor of suicide completion as a prior attempt. C. Active psychiatric disorder: Psychiatric disorders (e.g., depression, anxiety) increase suicide risk, but the presence of a prior attempt outweighs the risk from diagnosis alone. D. History of substance abuse: Substance abuse elevates risk, but the history of a prior attempt is the more immediate and critical predictor.