Following clinical training, Insel joined the NIMH as a clinical fellow working with Dennis Murphy. In 1980 he began the first U.S. research project on the biology of adults with
obsessive compulsive disorder (OCD), which was then largely treated with psychoanalysis. Following initial reports from Sweden, Insel was the first to demonstrate scientifically that a tricyclic antidepressant,
clomipramine, was effective for treating OCD. This observation not only launched the neuropharmacological study of OCD, it suggested the importance of developing the SSRI class of
antidepressants, which became a mainstay for treating both depression and OCD in the 1990s. {Zohar J, Insel TR, Zohar-Kadouch RC, Hill JL, Murphy DL. Serotonergic responsivity in obsessive-compulsive disorder. Effects of chronic clomipramine treatment. Arch Gen Psychiatry. 1988 Feb;45(2):167-72. doi: 10.1001/archpsyc.1988.01800260081011. PMID: 3276283.} Following this foray into clinical research, Insel moved from the clinic into the laboratory to study the
neurobiology of
emotion. Beginning in the NIMH Laboratory of Brain Evolution and Behavior started by
Paul Maclean in
Poolesville, MD, his group developed some of the classic studies for investigating
social behavior in animals, from
ultrasonic vocalizations in rodent pups to social attachment in
prairie voles to paternal care in
marmosets. A major focus was oxytocin, known to support
lactation and
parturition, but shown in
rats to be important for the initiation of maternal care by actions on brain
receptors. Oxytocin and the related hormone vasopressin were also found to be critical for
pair bonding in adult prairie voles. The Insel lab found that monogamous voles and non-monogamous voles (that did not pair bond) had brain receptors for oxytocin and vasopressin in different brain circuits, suggesting a mechanism for the evolution of
monogamy in mammals. In 1994 Insel was recruited to Emory University to direct the Yerkes Regional Primate Research Center, the nation's oldest and internationally one of the largest centers for research on monkeys and great apes. His tenure at Yerkes was marked by a focus on neurobiology and infectious disease, with a specific emphasis on development of an AIDS vaccine. This was also a period of considerable animal rights protests against Yerkes, with Insel and his family targeted by protesters opposed to invasive research with non-human primates. In 1999 Insel resigned from Yerkes to lead a new $40 million National Science Foundation Science and Technology Center, the Center for Behavioral Neuroscience. This new program used behavioral neuroscience to develop a cross-institutional training and research effort for 7 colleges and universities in Atlanta, with a specific goal of increasing the number of African American undergraduate students participating in neuroscience research.{https://cbn-atl.org/} This period was also a productive phase for social neuroscience research carried out at Emory. Larry Young, Zuoxin Wang, and Jim Winslow and several outstanding graduate students focused on the molecular biology, anatomy, and behavioral properties of oxytocin and vasopressin, providing critical evidence for the role of these neuropeptide systems in complex social behaviors. In his final years at Emory, Insel led the team into studies of autism, starting a new NIH funded Autism Center to investigate oxytocin and vasopressin as potential treatments for this disorder of social behavior.{Insel TR, Fernald RD. How the brain processes social information: searching for the social brain. Annu Rev Neurosci. 2004;27:697-722. doi: 10.1146/annurev.neuro.27.070203.144148. PMID: 15217348.} ==NIMH director==