It is well documented that interpersonal stress predicts the onset of depression, and that social isolation is a symptom of psychological distress that can leave patients with a poor prognosis for recovery. Therapeutic interventions focused on the alleviation of social conflict and strengthening of social bonds (i.e. Interpersonal Psychotherapy; IPT) show greater efficacy for the treatment of depression than other psychological interventions (NIMH Treatment of Depression Collaborative Research Program; Elkin et al. 1984). It has been posited that oxytocin, a naturally produced hormone that is involved in social-support seeking and stress-regulation, could represent a biological link between social stress and depression in adulthood. The salubrious effect of exogenous oxytocin on human social behavior is well documented: Oxytocin has been shown to make individuals feel more securely attached in their social relationships, increase their trust in others and openness to new ideas, improve their recall of specific and positive social autobiographical memories, and improve social learning. Importantly, these factors have been shown to improve the efficacy of Interpersonal Psychotherapy. Thus, It stands to reason that the use of oxytocin as an adjunct to IPT could improve its efficacy for the treatment of depression, which is an important prospect when considering that a third of patients do not respond to existing therapies.