Mood computational mechanisms underlying increased risk behavior in suicidal patients

Abstract

Suicidal thoughts and behaviors (STB) are one of leading causes of death worldwide. Although literature has consistently reported increased risk behavior in patients with STB and has proposed mood problems as the core of STB, cognitive and affective computational mechanisms underlying increased risky behavior remain unclear. Here, we asked 83 adolescent inpatients with affective disorders, where 58 patients with STB (S+) and 25 without STB (S-), and 118 gender/age-matched healthy control (HC) to make decisions between certain vs. gamble option with momentary mood ratings. After identifying increased risk behavior in S+than S-and HC, we used approach-avoidance prospect theory model and momentary mood model to quantify patients’ behavior and mood. Choice data analysis showed that heighted approach motivation mediated an increase in gambling choices with STB severity, suggesting impaired Pavlovian approach system in STB resulting in higher gambling in gains. Mood model showed lower mood sensitivity to certain reward in S+than S-and HC, which further explained increased gambling decisions in STB, offering a mood computational account for increased risk behavior in STB. These results remain significant after controlling for demographic and clinical variables and medication factors. Overall, our findings revealed cognitive and affective computational mechanisms underlying increased risk behavior in STB. This work has important implications for prevention and intervention of suicide, especially for clinical populations.