Oxytocin and psychotherapy: A pilot study of its physiological, behavioral and subjective effects in males with depression

Individual psychotherapy is an important treatment for a number of psychiatric conditions and involves a unique form of human attachment. This raises the question of whether oxytocin (OT), the paradigmatic “attachment hormone”, may have benefits in this context. In this randomized, double-blind, crossover trial, we gave male psychiatric outpatients with major depressive disorder 40 IU intranasal OT or placebo before a videotaped session with a therapist and measured a number of subjective, physiological, and behavioral parameters. We report three main findings. Surprisingly - in contrast to prior reports of OT's anxiolytic properties - we found OT caused an increase in anxiety over the course of the therapy session. Secondly, though it had no main effect on cortisol, eye contact, or overall behavior, we did find that OT caused a decrease in nonverbal behaviors that cut off social contact, after controlling for level of depressive symptoms. Lastly, we replicated prior findings that OT improves social cognition (performance on the reading the mind in the eyes test (RMET)), albeit in a depressed patient group. These results inform future studies of oxytocin and psychotherapy and suggest that in certain clinical populations and contexts, OT has heterogeneous subjective effects which may include acute anxiogenesis. Moreover, the similarity of some of these acute effects to those of single-dose serotonergic antidepressants raises interesting questions about the potential antidepressant benefits of chronic OT administration.