Psychobiological Markers of Suicidal Ideation : a Case-Control Study

Background: Approximately one million people die from suicide worldwide every year. Suicide risk evaluation principally depend on clinicians’ experiences and an unmet need amongst health care providers is sufficient suicide risk assessment. To identify individuals at high risk for suicide is an important public health issue. Aims: To determine whether neurocognitive functional tests (including Cambridge gambling test, symmetry span task, Intra-Extra dimensional set shift task, and Stopsignal task), and/or biomarkers i.e. heart rate variability (HRV) and brain imaging (structural MRI and resting function MRI) can identify at risk individuals for suicide. Methods: 50 participants aged between 20 and 60 years old with major depressive disorder and current suicidal ideation will be recruited from a regional teaching hospital. Two groups of comparison participants encompassing 50 major depressive disorder participants without current suicidal ideation and 50 control participants without major depressive disorder nor suicidal ideation. Written informed consents will be obtained after complete description of the study to the participants. All participants will first be assessed a structured interview (including assessment of psychiatric disorders, personality, impulsivity, suicide ideation and depression level) carried out by a trained psychiatric nurse. All participants will receive fMRI and diffusion MRI scanning. Following the brain imaging, they will complete the heart rate variability (HRV) and the neuropsychological tests (suicide IAT, SSPAN, AFT and IGT, counterbalanced across participants). The tests will be carried out by a trained psychology master. Significance: The current proposed study is the first one to apply the framework of cold and hot executive functions to assess current suicidal ideation. This is also the first study to validate the application of generalized q-sampling imaging (GQI), and HRV in current suicidal ideation. Anticipated results: The findings emerging from the present study will confirm the predictive potential of combining psychobiological markers (neuropsychological tests, HRV and brain imaging) to assist in screening and stratifying risk for suicide in adults with MDD at risk for suicide.

Project ID:PC10507-1265
External Project ID:MOST105-2314-B182-028