Objective and subjective suicidal intent are differentially associated with attempt lethality based on age of onset of suicidal behavior

Predicting the medical seriousness, or lethality, of suicide attempts remains challenging for clinicians, as impulsive and planned attempts can both be fatal and risk may vary with age and suicidal intent. We investigated whether attempt lethality is driven by practical preparedness (objective suicidal intent) and/or psychological resolve (subjective suicidal intent) and whether these associations vary with age of onset of suicidal behavior. The study used a cross-sectional lifespan sample (N = 95; age range 16-76 years) with current depression and recent suicidal behavior (≤ 5 years). Linear regression models indicated that older age of onset of suicidal behavior (B = 0.86, SE = 0.20, p < 0.001), and both higher objective intent (B = 0.69, SE = 0.19, p < 0.001) and subjective intent (B = 0.50, SE = 0.20, p = 0.014) were associated with more severe lethality at the most recent attempt, although the association with subjective intent was driven by its shared portion with objective intent. The association between objective intent and lethality was stronger with older age of onset (interaction B = 0.75, SE = 0.20, p < 0.001), whereas the association between subjective intent and lethality was stronger with younger age of onset (interaction B = - 0.42, SE = 0.20, p = 0.036). Our findings suggest that contextualizing suicidal intentions with age of onset, rather than age at the current suicidal crisis, can help clinicians better appraise suicide risk.