b'EARLY CAREER RESEARCHER GRANTNDynorphin/Kappa Opioid Receptor Signaling Role inKetamines Anti-Suicidal Ideation EffectElizabeth Bartlett, Ph.D.Research Foundation for Mental Hygiene, IncMentor: John Mann, M.D.Research Foundation for Mental Hygiene, Inc $140,000It is of interest to suicide prevention to explore how stress, suicidal thoughts, and the effects of ketamine are connected in people with depression. Stress increases the risk for suicidal thoughts, but the biological basis is unclear. Ketamine may help reduce suicidal thoughts by affecting stress-linked brain systems. This study will use smartphone tracking to monitor real-time responses to stress and positron emission tomography (PET) brain scans to study how ketamine affects brain pathways related to stress and suicidal thoughts in depressed individuals.23'