Does Oxytocin Impact the Psychotherapeutic Process? An Explorative Investigation of Internet-Based Cognitive-Behavioral Treatment for Posttraumatic Stress Disorder

Background: Oxytocin might promote favorable psychotherapy outcomes by strengthening the therapeutic alliance. Its involvement in psychotherapeutic processes, especially regarding the therapeutic alliance, needs further investigation. Patients and Methods: Blood oxytocin of 35 male German Armed Forces service members who were seeking treatment for posttraumatic stress disorder (PTSD) was analyzed before the onset of a 5-week internet-based, trauma-focused psychotherapy. We investigated whether oxytocin influenced patients' ratings of the therapeutic alliance components "agreement on collaboration" and "emotional bond," assessed during and after treatment. We further explored oxytocin's impact on general change mechanisms of psychotherapy and on psychotherapy expectation and evaluation. Results: Oxytocin had no significant impact on early agreement on collaboration, which significantly predicted psychotherapy outcome. Early emotional bond was not predicted by oxytocin and was not predictive for psychotherapy outcome. Descriptive analyses showed that patients with higher pretreatment oxytocin concentrations provided higher ratings of general change mechanisms of psychotherapy. On a descriptive level, the associations between psychotherapy expectation and evaluation and oxytocin were mixed. Discussion and Conclusion: We found positive effects of higher pretreatment oxytocin concentrations in PTSD patients. This descriptive study is limited by its small sample size and needs replication in larger, independent samples. However, results indicate possible benefits of oxytocin on trauma-focused psychotherapy.