Scientists Probe Oxytocin Therapy for Social Deficits in Autism, Schizophrenia

Abstract

EMERGING EVIDENCE INDICATES THAT oxytocinplaysan important role in human social interactions, and preliminary clinical studies suggest the hormone may help improve social functioning in individuals with autism or schizophrenia. But experts caution that much remains to be learned about oxytocin and its physiological effects before it is ready for clinical use. Oxytocin has long been known to help facilitate mother and infant bonding. Research on the socially monogamous prairie vole has demonstrated that the hormone plays a much wider role in helping to establish social bonds among animals. The animal findings have led to studies in humans to assess how exposure to the hormone affects human interactions, including early clinical studies in individuals with social impairments related to such disorders as autism and schizophrenia. Still, a host of questions remain about the hormone’s wider physiological effects on humans, which range from aiding lactation to potentially promoting healing, noted Sue Carter, PhD, professor of psychiatry and co-director of the Brain-Body Center at the University of Illinois, in Chicago. In addition, data on the safety and effects of chronic use of oxytocin are limited because many human studies have involved only a single intranasal dose or several weeks of administration. “Oxytocin research is exciting and promising, but how the information should be applied is not clear,” Carter said in an interview. “What we have now are fragments of knowledge, and we can’t yet see the full picture.” INCREASING SALIENCE In the past several years, scientists have learned that oxytocin plays an important reinforcing role in social interactions that goes far beyond the previously documented effects of the hormone in female reproduction. Oxytocin has long been known as a key factor in bonding between a mother and infant. It also has important physiological effects on pregnant women during and after delivery. A synthetic version of oxytocin is widely used to induce or augment labor. Intranasal oxytocin has also been used to promote the release of breast milk. Now, basic research on an unusual animal model has allowed scientists to understand the wider physiological effects of oxytocin. Carter began working with prairie voles with a field biologist and colleague, Lowell Getz, PhD, at the University of Illinois, in Urbana-Champaign, who was studying them in the wild. Field evidence on the voles suggested they live in lifelong pairs, and Carter brought them into the laboratory to study the physiology behind this behavior, hoping to gain insights that might be relevant to human relationships. Other groups also began working with the animals, which became a laboratory model for understanding the endocrinology behind sociality, according to Carter. The voles are one of the few species besides humans with a complex family structure, according to Larry J. Young, PhD, director of the Center for Translational Social Neuroscience at Emory University, in Atlanta, who summarized this area of research at the Society for Neuroscience annual meeting in San Diego in November. In an interview, he explained that while strong bonds between mother and offspring are common in many species, few species form lasting bonds between the mother and father. “The male and female prairie voles work as a team [to raise their offspring], as humans do,” Young said. Carter’s group was able to demonstrate that giving oxytocin to a female vole promotes bonding with her mate,