Funding Organization: American Foundation for Suicide Prevention Study Title: White Matter Integrity and Suicide Risk: Histologic Evaluations of Potential DTI Targets

Our goal is to study autopsy brains in order to localize abnormalities that could be identified on magnetic resonance imaging (MRI) of live patients to assess suicide risk. We will use uniform random sampling to conduct histological analyses of myelin integrity and microglial activation in frontal white matter from autopsy brains that we have already collected from 27 suicide cases and 27 nonsuicide cases matched for diagnosis, age, sex, and medication history. The data will allow us to identify and to localize subtle variations in white matter integrity that may be associated with suicide. We will also examine whether such abnormalities are associated with a history of aggressiveness or violent behavior, characteristics that have been associated with suicide and that may be associated with abnormalities in prefrontal white matter. White matter abnormalities can be recognized in live subjects with high sensitivity by diffusion weighted MRI and magnetization transfer MRI. Finding a white matter abnormality that is associated with suicide could allow the use of MRI to help assess suicide risk in individuals, so that close observation and other intense preventive efforts could be directed towards those individuals for whom they are most needed. Funding Organization: American Foundation for Suicide Prevention Study Title: Cognitive and Biological Responses to Social Stimuli as Longitudinal Predictors of Adolescent Girls’ Suicidality Principal Investigator: Mitchell Prinstein Year When Study First Received Funding: 2008 Abstract: To understand how specific biological and social-cognitive responses to interpersonal stress may be associated with a greater likelihood of future suicidal ideation and behavior among adolescent girls. This study offers a rare opportunity to examine adolescent girls' responses to interpersonal stimuli using a labbased, experimental paradigm, and a longitudinal design. Adolescent girls will be asked to participate in an established interpersonal stressor during a videotaped lab-based visit, and to complete measures of suicidality at four time points (baseline, 3, 6, and 9 months later). Measures of HPA Axis functioning and vagal tone/suppression will be obtained to measure biological responses, and videotapes will be analyzed and coded to measure social-cognitive responses. Past research has identified stressor domains (i.e., school, family, peers) associated with suicidality, but little research has addressed how or why these stressors lead to adolescents' decisions to engage in suicidal behavior. By examining both social-cognitive and biological responses to interpersonal stimuli, this study offers an integrative model with direct implications for preventive interventions; it will be possible to more accurately identify adolescents at risk and to modify processes that mediate the link between stressful events and suicidal behavior.