Thomas Roland Insel is an American neuroscientist and psychiatrist who has led the National Institute of Mental Health (NIMH) since 2002. Prior to becoming Director of NIMH, he was Director of the Center for Behavioral Neuroscience at Emory University in Atlanta, Georgia. He is best known for research on oxytocin and vasopressin, two peptide hormones implicated in complex social behaviors, such as parental care and attachment. He announced on Sept. 15, 2015, that he was resigning as the director of the NIMH to join the Life Science division of Google X.