Mood computational mechanisms underlying increased risk behavior in adolescent suicidal patients

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. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement National Natural Science Foundation of China ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The ethical committee of The Clinical Hospital of Chengdu Brain Science Institute, University of Electronic Science and Technology of China gave ethical approval for this work. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The data that support the findings of this study are available from the corresponding author upon reasonable request.