This discovery is the result of a study launched by the UCSD School of Medicine in October 2010. The study, based on prior scientific research that indicates that oxytocin has the potential to treat depression and other mood disorders, will conclude in October 2012. The clinical trial is administered in part by UCSD Assistant Clinical Professor of Psychiatry Dr. Kai MacDonald.

This trial follows double-blind clinical standards. One group of subjects takes a twice-daily intranasal dosage of 40 micrograms of synthetic oxytocin while another group receives a placebo. After one week, the amount is increased to 80 micrograms and the trial continues for three more weeks at this dosage. The experimenters will discover which group each subject belongs to only after all scientific data has been collected and analyzed. This allows for the most accurate and unbiased conclusions.

The synthetic form of the hormone is chemically identical to the oxytocin the body produces, MacDonald said. 

All patients involved in the study have been diagnosed with either major depressive disorder or neurotic depression, but are stable. Their results are measured using the Montgomery-Asberg scale, a clinician-rated depression scale based on 10 psychiatric inquiries, including the subject’s appetite, sleep, ability to concentrate and prevalence of suicidal thoughts.

Results have indicated that oxytocin helps to alleviate depression-related symptoms, indicated by a positive change reported in the patient’s health status. The clinical study is still recruiting participants.

The research could lead to change in the chemical makeup of existing antidepressants, or provide a completely different source of treatment for the disorder. 

“We’re doing the initial pilot study to see if this can either augment what people are already on, or treat — if they’re not on medicine — depression,” MacDonald said.

UCSD scientists have been looking into the beneficial effects of the naturally occurring hormone for a couple of years now.

MacDonald and fellow UCSD Professor of Psychiatry Dr. David Feifel have also researched the effects of oxytocin on anxiety disorders in 2010, and on schizophrenia in 2011. According to their research, oxytocin functions as an anti-psychotic and anti-anxiety agent.

“This is the third in an inestimably long list of trials; the oxytocin system is a natural endogenous system in your brain like the serotonin and dopamine systems,” MacDonald said. “There are all kinds of conditions that could theoretically benefit. We’re just picking off the most likely candidates, but there are many more.”

Common anti-depressants use serotonin to initiate changes in brain chemistry, which can alleviate depression. Oxytocin directly interacts with the dopamine and serotonin systems, both of which affect depression and its symptoms, MacDonald said. 

“One possible hypothesis about how oxytocin may help depression is interaction with other brain systems that we know influence depression,” MacDonald said.