Repetitive negative thinking as a unique transdiagnostic risk factor for suicidal ideation.

Repetitive negative thinking (RNT) is a transdiagnostic symptom observed across mood and anxiety disorders and is characterized by frequent, distressing thoughts that are perceived as uncontrollable. Specific forms of RNT have been linked to increased suicide risk. However, most work examining links between RNT and suicide has been conducted within specific disorders and subtypes of RNT (e.g., rumination in individuals with depression). The present study aimed to investigate associations between transdiagnostic RNT and suicidal ideation. We hypothesized RNT would be associated with suicide risk beyond disorder-specific clinical symptoms. Fifty-four participants with mood, anxiety, and/or traumatic stress disorders completed an interview assessing suicidal risk (Columbia-Suicide Severity Rating Scale (C-SSRS)) and self-report questionnaires assessing transdiagnostic RNT, depression, and anxiety. Based on C-SSRS, we divided participants into high or low suicide risk groups. We analyzed the relationship between suicidal risk group and RNT and found that RNT was uniquely associated with suicidal risk group, controlling for depression and anxiety severity. Our results suggest including assessments of RNT may have clinical utility for understanding the degree of suicide risk in individuals and point to the potential utility of including clinical interventions to target this symptom for those at high risk of suicide.