Oxytocin -- "the love hormone" -- may enhance compassion of people suffering from symptoms of post-traumatic stress disorder (PTSD), according to new study conducted at the University of Haifa and Rambam Health Care Campus.

"The fact that the present study found that Oxytocin may improvement compassion among patients with post-traumatic stress disorder toward women provides new evidence that oxytocin may be able to improve the social behavior of these patients," said Professor Simone Shamay-Tsoory from the Department of Psychology at the University of Haifa, who led the study.

Compassion is pro-social motivation to help others who are in distress. It is an outcome of emotional of empathy -- the ability to recognize the feelings of others, and cognitive empathy -- the ability to understand what another person feels and think. It is known from recent studies that compassion is mediated through different areas of the brain associated with those both components of l empathy.

In the present study -- conducted by Professor Shamay-Tsoory together with Professor Ehud Klein, Director of Psychiatry at the Rambam Medical Center, and Dr. Sharon Palgi, the Head of the psychologists' team in the Psychiatric Day-Care Department at Rambam Medical Center, who conducted the study as part of her Ph.D. work at the University of Haifa -- the researchers examined whether patients with post-traumatic stress disorder suffer from deficits in compassion. In addition, the researchers sought to investigate whether intranasal oxytocin, a hormone that's known to modulate social behaviors, may enhance compassion in these patients.

The study included 32 patients with post-traumatic stress disorder and 30 healthy subjects with no history of psychiatric disorders. All participants were randomly assigned to groups for the first administration of either Ocytocin or placebo (a substance having no pharmacological affect). One week later, each participant underwent a second administration, switching to the other treatment administration (Oxytocin or placebo). 45 minutes after receiving the treatment participants were requested to listen to two randomly chosen different stories, of protagonists (one with a male protagonist and one with a female protagonist) describing distressful emotional conflicts, and to provide compassionate advice regarding his distress. The compassion degrees in the participant's responses to the stories were analyzed by two psychologists who didn't know whether the patient had been administered oxytocin or the placebo.

The results showed that patients with post-traumatic stress disorder showed less compassion for other (the average compassion score of PTSD patients was 3.39, while that of the healthy patricians was 5.05), and were less talkative (the average length of responses PTSD patients was about 31 words, while that of healthy patricians was 47 words), compared to healthy control patricians. The findings suggest that patients with PTSD suffer from significant and comprehensive deficits in compassion. These deficits may indicate that in response to the distress of the other, patients with PTSD may have difficulty in inferring and understanding the circumstances leading to this distress, and may failed to act with compassion in light of distress others. "The difficulty in the ability to feel compassion may be due to problems in the ability to identify, understand, and empathize with the other's state of distress, i.e., difficulties in emotional and cognitive empathy. These difficulties in empathy and compassion may relate to social problems that characterize patients with post-traumatic stress disorder," said the researchers.

The study also found that a single intranasal dose of Oxytocin enhances compassion, both in patients with PTSD and in healthy participants -- but only toward women, while it does not affect compassion toward men. From an evolutionary perspective one of the Oxytocin roles is to moderate pro-social behaviors, including compassion, mainly toward the survival of weaker and vulnerable individuals within groups, including females, pregnant females and offspring, who cannot defend themselves in nature, in light of the stress. This evolutionary explanation can illuminate the findings from the current study, that Oxytocin enhance compassion towards women, but not toward men. "If the stories of children with distress were included in our study, it is possible that Oxytocin enhances compassion toward that stories even more," they remarked.

This finding led the researchers to assume that in the future it may be possible for Oxytocin to be used as a psychobiological treatment option in couple therapy as it may increase positive communication behaviors among partners, particularly among couples where the husband suffers from PTSD, and thereby it may improve the quality of the couple's marriage -- which is often impaired by the disorder.

"Until now, several theoretical studies proposed that oxytocinergic system functions abnormally among patients with PTSD and that intranasal OT may potentially serve as an effective pharmacological intervention for ameliorating symptoms of PTSD, but very few studies have examined the effects of OT administration among these patients, and to the best of our knowledge the effects of OT on empathy and compassion among patients with PTSD have never been assessed. For this reason, the findings of the present study are both significant and innovative," the researchers concluded.

The study was published in the journal Psychoneuroendocrinology.