Childhood trauma, psychosis risk, cognition, and depression have been identified as important risk markers for suicidal behaviors. However, little is known about the interplay between these distal and proximal markers in influencing the risk of suicide. We aim to investigate the interplay between childhood trauma, cognitive biases, psychotic-like experiences (PLEs) and depression in predicting suicidal behaviors in a non-clinical sample of young adults.

In total, 3495 young adults were recruited to an online computer-assisted web interview. We used the Prodromal Questionnaire to assess PLEs. Childhood trauma was assessed with the Traumatic Experience Checklist (three items) and Childhood Experience of Care and Abuse Questionnaire (CECA.Q, three items). Cognitive biases were assessed with a short version of the Davos Assessment of Cognitive Biases Scale. Suicidality, psychiatric diagnoses, and substance use were screened with a self-report questionnaire.

Childhood trauma, as well as PLEs, was associated with an approximately five-fold increased risk of suicidal thoughts and plans as well as suicide attempts. Participants with depression were six times more likely to endorse suicidal behaviors. Path analysis revealed that PLEs, depression and cognitive biases are significant mediators of the relationship between trauma and suicidal behaviors. The model explained 44.6% of the variance in lifetime suicidality.

Cognitive biases, PLEs, and depression partially mediate the relationship between childhood trauma and suicidal behaviors. The interplay between distal and proximal markers should be recognized and become part of clinical screening and therapeutic strategies for preventing risk of suicidality.