Most of us know what it's like to lose a loved one. With loss comes a veritable smorgasbord of emotional turmoil and a long period of grieving as we struggle to come to terms with the drastic change.
While most grieving adults gradually adjust to their loss, about 10-15 percent of people develop what is known as complicated grief. Sufferers experience persistent intense yearning, emotional pain and an inability to carry out the normal functions of daily life long after their loved one has passed.
The key to understanding the biological mechanism underlying complicated grief may lie in the neuropeptide hormone oxytocin, commonly implicated in facilitating social bonding and maternal behavior. University of Arizona psychologist Mary-Frances O'Connor has received a $200,000 grant from the Dana Foundation to study oxytocin's role in complicated grief and its potential to reverse associated symptoms.
"We are very interested in the way emotion and physiology interact," said O'Connor, an assistant professor in the Department of Psychology. "In complicated grief, people become more vulnerable to illness. We want to know what's going on physiologically that is preventing a normal healing process from occurring."
Adults who recently have lost a spouse or a child represent the majority of people who develop complicated grief. O'Connor and her team plan to use functional magnetic resonance imaging, or fMRI, to study the brains of 40 such adults and determine whether intranasally administered oxytocin changes their experience of grief and their neural responses.
In previous neuroimaging studies, O'Connor found that people who were experiencing signs of complicated grief exhibited higher levels of the stress hormone cortisol. They also showed greater activity in a brain region called the nucleus accumbens when looking at a picture of their recently deceased spouse, compared to those who were experiencing a typical grieving process.
The nucleus accumbens is typically associated with motivation and reward, both of which are relevant to symptoms of complicated grief. O'Connor thinks that abnormally low levels of oxytocin bound to receptors in the nucleus accumbens during bereavement may be responsible.
"Neurons in the nucleus accumbens express oxytocin receptors, and oxytocin has also been shown to inhibit the action of cortisol," O'Connor explained. "These facts and our findings suggest complicated grief may in fact be a state of oxytocin dysregulation."
Participants in the study will receive an oxytocin or saline intranasal spray before one fMRI scan, and get the other spray as a control when they come back for a second scan. O'Connor and her team then will use the neuroimaging data to determine if there are any differences in the levels of nucleus accumbens activity after oxytocin administration. The team also will ask participants to detail their emotional experiences when viewing a picture of their deceased spouse under both conditions.
Previous experiments have shown that the positive psychological effects resulting from intranasal oxytocin, which generally include reports of increased calm and contentment, are short-term, lasting only about 20 to 30 minutes. For this reason, O'Connor emphasized that nasal oxytocin is meant to elucidate the biological mechanisms underlying complicated grief, not serve as long-term therapy.
If oxytocin does reduce signs of complicated grief and O'Connor's hypothesis is confirmed, she and her team will next try to understand why oxytocin is deficient in people who develop complicated grief. O'Connor hopes that her findings may eventually lead to potential therapies for those in need.
"If we can confirm and understand the relationship between the action of oxytocin and symptoms of complicated grief, we might be able to develop methods of stimulating natural oxytocin production and release in individuals who are suffering," O'Connor said.