A Preliminary Examination of Endogenous Peripheral Oxytocin in a Pilot Randomized Clinical Trial of Oxytocin-Enhanced Psychotherapy for Posttraumatic Stress Disorder

Background: Preclinical and clinical research suggests that the oxytocin system is implicated in the development and maintenance of stress and anxiety-related psychiatric conditions, such as posttraumatic stress disorder (PTSD). Recent research also suggests that intranasal oxytocin holds promise as a treatment for PTSD. However, little is known about the relationship between levels of peripheral oxytocin and PTSD symptom severity, PTSD treatment response, and repeated intranasal oxytocin administration.

Methods: In the current study, we examined associations between PTSD symptom severity and peripheral oxytocin levels measured in plasma before and after a course of prolonged exposure (PE) for PTSD (n = 13); participants were randomized to adjunctive intranasal oxytocin (n = 6) or placebo (n = 7).

Results: Baseline peripheral oxytocin levels were not associated with baseline PTSD symptom severity. Change in peripheral oxytocin levels did not differ by treatment condition and did not correspond to change in PTSD symptoms.

Conclusions: This proof-of-concept study illustrates the acceptability and feasibility of measuring peripheral oxytocin among individuals engaged in psychotherapy for PTSD and informs the utilization of these procedures in future adequately powered studies.