The impact of different neurobehavioral symptoms on suicidal ideation and perceived likelihood of future suicidality.

Existing literature suggests that psychological and functional impairment, independent of head injury severity, can increase suicide risk. This study explores the impacts of self-perceived dysfunction within four neurobehavioral symptom clusters-vestibular (e.g., dizziness, balance), somatosensory (e.g., headaches, nausea, vision), affective (e.g., anxious, irritable mood), and cognitive (e.g., concentration, memory, indecision)-on current suicidal ideation and the perceived likelihood of future suicidal ideation and attempts. Community participants (n = 309; Mage = 36.88; 51.6% female; 79.6% White) completed the Neurobehavioral Symptom Inventory (NSI) and the Self-Injurious Thoughts and Behaviors-Short Form (SITBI-SF). Quantile regression analysis was used to explore the effects of the four neurobehavioral symptom clusters at different levels of suicidal ideation intensity, perceived likelihood of future suicidal ideation, and self-perceived likelihood of future suicide attempt. Controlling for past head injuries and suicide attempts, affective symptoms were significantly associated with a moderate and high average intensity of current suicidal ideation. Somatosensory symptoms were significantly associated with a moderate perceived likelihood of future suicidal ideation. Finally, vestibular symptoms were significantly associated with a moderate perceived likelihood of a future suicide attempt. These findings highlight the critical need to consider a broader spectrum of symptoms, including chronic physical symptoms, when assessing suicide risk. Furthermore, they underscore the need to expand beyond affective symptoms as an explanation for increased suicidality and examine additional mechanisms through which chronic physical symptoms can increase suicide risk.