Oxytocin (OT) is a neurohypophysial hormone and neuropeptide produced by the hypothalamus
and released by the pituitary gland. It has multiple physiological roles including
stimulation of parturition and lactation, and promotion of pro-adaptive social behaviors
necessary for mammalian survival. OT interacts with one receptor subtype: the OT receptor
(OTR), which, upon stimulation, triggers different intracellular signal transduction
cascades to mediate its physiological actions. Preclinical studies show that OT regulates
social behaviors such as pair bonding, recognition and social interaction. It also
coordinates the activation of the hypothalamic-pituitary-adrenal (HPA) axis and the
release of corticotrophin-releasing hormone. Further evidence suggests that OT plays
an important role in regulating caloric intake and metabolism, and in maintaining
electrolyte and cardiovascular homeostasis. OT is also involved in attenuating the
neurophysiological and neurochemical effects of trauma on the brain and body by facilitating
both physical attachment such as wound healing, and psychological/social attachment,
thereby increasing resilience to subsequent traumatic events. Clinical trials have
reported that intranasal administration of OT provides therapeutic benefits for patients
diagnosed with traumatic stress-related diseases such as major depressive disorders
and post-traumatic stress disorder. OT's therapeutic benefits may result from context-dependent
interactions with key neural pathways (social, cognitive, and reward), neurotransmitters
(dopamine, norepinephrine, serotonin, and endogenous opioids), and biomarkers (adrenocorticotropic
hormone, cortisol, and dehydroepiandrosterone sulfate), that lead to a decrease in
stress associated behaviors, and facilitate post-traumatic growth, ultimately leading
to increased resilience, through improved social cohesion and attachment. OT induced-augmentation
of physical and cognitive resilience may play a significant role in both the prevention
of, and improved clinical outcomes for, traumatic stress-related disorders following
either acute or enduring traumatic experiences.
