07/25/2013 09:07 am ET Updated Jul 25, 2013

Oxytocin Could Increase Anxiety, Fear In Response To Future Stress


The "love hormone" may not be as warm and fuzzy as we thought. A new study shows that while oxytocin does play a huge role in social bonding and feelings of love, it also is the reason why terrible events can scar you for life.

This new finding is important because "by understanding the oxytocin system's dual role in triggering or reducing anxiety, depending on the social context, we can optimize oxytocin treatments that improve well-being instead of triggering negative reactions," study researcher Jelena Radulovic, the Dunbar Professsor of Bipolar Disease at Northwestern University's Feinberg School of Medicine, said in a statement.

The study, published in the journal Nature Neuroscience and conducted in mice, explains that oxytocin can not only make us remember stressful situations from the past (like being bullied), but they also increase feelings of anxiety and fear in the face of future stress.

The hormone does this by triggering a molecule called ERK, which itself makes sensations of fear greater because it stimulates fear pathways in the brain's lateral septum region. This molecule is activated for hours after a stressful social experience.

Researchers noted this is the first time oxytocin has been identified to have a function that isn't just boosting feelings of love and connection. Past studies have looked at the hormone's role in relationships and friendships. For instance, a study in the journal Psychoneuroendocrinology earlier this year showed that oxytocin makes people more likely to "tend and befriend" others who have just experienced social rejection. And a 2012 study showed that oxytocin levels could be a predictor for how long a relationship lasts.