A hallmark of autism is impairment in reciprocal social interaction, including inadequate eye contact and failure to recognize emotions. Research shows that the neuropeptide oxytocin modulates social behavior. In mice, rats, monkeys and sheep, for instance, administration of oxytocin enhances social recognition, memory of peers, and development of partner preference and bonding. In people, including those with autism, oxytocin nasal spray can significantly enhance social cognition.
The therapeutic effectiveness of oxytocin nasal spray may be limited, however, because it does not readily pass the blood-brain barrier. Adam Guastella and his colleagues at the University of Sydney in Australia are testing an alternative approach: stimulating oxytocin release within the body.
Receptors for the hormone melanocortin 4 (MC4) have been shown to induce the release of oxytocin in the central but not peripheral nervous system. Guastella’s group is planning to test a safe synthetic peptide that acts on MC4 receptors to produce an effect similar to that of melanocortin (i.e., a melanocortin agonist). Their first study is designed to determine the effects of the agonist on social cognition. They plan to alternate giving the drug and a placebo to 30 neurotypical participants and 30 participants diagnosed with autism. After drug administration, the participants’ social behavior will be assessed through experimental tasks. The researchers expect that treatment with the melanocortin agonist will lead to increased eye gaze, quicker and more accurate identification of emotions from faces, and an improved capacity to correctly respond to social cues.