What is recognized as the strongest indicator for predicting future suicidal behavior?

The strongest indicator for predicting future suicidal behavior is past suicidal behavior. Research consistently shows that individuals who have previously attempted suicide are at significantly higher risk for future attempts and completed suicides. This historical behavior serves as a critical marker because it reflects a person's capacity for self-harm and indicates that they may have unresolved psychological issues, a lower threshold for distress, and potentially a lack of coping mechanisms to deal with life’s challenges effectively.

In addition to being the most robust predictor, past suicide attempts are also associated with the severity of mental health disorders, impulsivity, and chronic stressors, which further compound the risk. This highlights the importance of assessing an individual's history of suicidal ideation and attempts during evaluations to better inform treatment plans and preventive strategies.

Other factors, while relevant, do not hold the same predictive power as past suicidal behavior. Age may influence risk, but it varies widely among individuals. Substance use can increase impulsivity and risk, however, its role may depend on other underlying factors and is not as directly correlated with suicidal outcome as past attempts. Psychosis does indicate an elevated risk of suicide, especially if associated with significant distress or command hallucinations, but again it does not equate to the direct and established link demonstrated by previous suicidal behaviors.