Relationship of plasma oxytocin levels to baseline symptoms and symptom changes during three weeks of daily oxytocin administration in people with schizophrenia

Abstract

Several clinical studies have found an inverse relationship between clinical symptoms and peripheral oxytocin (OT) levels in people with schizophrenia. As oxytocin is a putative treatment for schizophrenia, the effect of repeated dosing of OT on OT levels, clinical symptoms and the relationship between the two is of interest. In a, randomized, double blind, parallel group 3 week study (N=28) with daily administration of intranasal OT (20 IU twice daily) or placebo (PBO), we examined the effect of OT administration on the correlation between the change in peripheral OT levels and change in clinical symptoms in patients with schizophrenia. At baseline, there were no significant treatment group differences in OT levels. There were no significant associations between baseline OT levels and any symptom measures. After 3 weeks of OT/PBO dosing, there was no significant difference in the magnitude of change in OT levels between the two treatment groups. Correlations between changes in peripheral OT levels and changes in the BPRS total and negative symptom scores were not different between treatment groups. Larger studies are needed to examine the effect of exogenous OT on peripheral OT levels and the relationship between the latter and clinical symptoms. Clinical Trials.gov=NCT00884897.

Trial registration: ClinicalTrials.gov NCT01699997.

Keywords: Intranasal; Negative symptoms; Oxytocin; Oxytocin levels; Positive symptoms; Schizophrenia.

Conflict of interest statement

CONFLICTS OF INTEREST

Dr. Kelly has served as an advisor for XOMA and Lundbeck, Dr. Buchahan served on the advisory boards for Amgen, Astellas, Janssen Pharmaceuticals, Inc., NuPathe, Inc., Pfizer, Roche, and Takeda. He also serves as a DSMB member for Pfizer and Otsuka. Dr. McMahon served as a consultant for Amgen. Other authors have no conflicts of interest to report.

Published by Elsevier B.V.

Figures

Figure 1

Figure 1a. Association between the change score in peripheral oxytocin (OT) levels (baseline – 3 weeks) and the change score in the BPRS total score (baseline – 3 weeks). Improvement is noted by negative values for change in BPRS total score. Oxytocin level units are pg/mL Figure 1b. Association between the change score in peripheral oxytocin (OT) levels (baseline – 3 weeks) and the change score in the BPRS negative symptom score (baseline – 3 weeks). Improvement is noted by negative values for change in BPRS negative symptom score. Oxytocin level units are pg/mL

Figure 1

Figure 1a. Association between the change score in peripheral oxytocin (OT) levels (baseline – 3 weeks) and the change score in the BPRS total score (baseline – 3 weeks). Improvement is noted by negative values for change in BPRS total score. Oxytocin level units are pg/mL Figure 1b. Association between the change score in peripheral oxytocin (OT) levels (baseline – 3 weeks) and the change score in the BPRS negative symptom score (baseline – 3 weeks). Improvement is noted by negative values for change in BPRS negative symptom score. Oxytocin level units are pg/mL