Which youth with suicidal ideation will go on to make a suicide attempt? A systematic review

Suicidal ideation is common among adolescents, yet most who experience it never make a suicide attempt. Identifying which youth go on to engage in suicidal behavior remains one of the most pressing challenges in clinical psychiatry. This systematic review synthesizes the evidence on risk and protective factors that are associated with the transition from suicidal ideation to suicidal behavior in adolescents and young adults. We searched five electronic databases from inception through November 2025, yielding 52 studies meeting eligibility criteria. Included studies assessed suicidal ideation at a defined baseline and measured subsequent suicidal behavior, evaluating at least one predictor of that transition in samples with participants under age 30. Across case-control, retrospective, and prospective designs, the strongest predictors of transition were characteristics of the ideation itself, particularly the presence of a plan or intent, high duration and intrusiveness, and lack of controllability. Past suicidal behavior and non-suicidal self-injury were also robust predictors. Psychiatric comorbidity, especially mood disorders combined with externalizing disorders, substance use, or post-traumatic stress disorder, meaningfully increased risk, as did maltreatment, peer victimization, and family conflict. Conversely, parent-child connection, social support, and school connectedness were protective. Findings from this review can inform more precise clinical risk assessment and help identify the highest-priority targets for intervention among youth presenting with suicidal ideation.