Although life stressors are known risk factors for suicide, the specific stressor types that most strongly precipitate suicidal outcomes, and on what timescale, remain poorly understood. Based on existing theory, we investigated whether objectively rated interpersonal stressors, especially social and targeted rejection stressors, are proximally associated with increased likelihood of suicidal ideation and behavior.

Using an objectively rated contextual threat interview to assess stressful life events, and a timeline followback procedure for assessing suicide-related outcomes, we examined how the severity of four types of acute life events (i.e. non-interpersonal, interpersonal without social rejection, social rejection without targeted rejection, and targeted rejection) were temporally associated with the likelihood of same-day and next-day suicidal ideation and behavior over 16 months in 143 young adults (Mage = 25.27, SD = 4.65) with recent suicidal ideation or behavior.

After controlling for prior-day suicidal ideation and non-interpersonal stressors, daily within-person increases in interpersonal stressor severity were related to higher odds of same-day (but not next-day) suicidal ideation. Additionally, greater increases in targeted rejection severity were uniquely related to increased likelihood of both same-day and next-day suicidal behavior after controlling for prior-day suicidal behavior and other types of stressors.

Interpersonal stressors are strong, proximal risk factors for suicidal ideation and behavior, and these effects are particularly strong for targeted rejection life events. Clinicians should thus assess recent interpersonal and, especially, targeted rejection stressors when evaluating acute suicide risk, and may reduce such risk by helping patients stabilize and strengthen their social relationships.