Stress hormones may promote brain's building of negative memories in women, according to a recent study.

Researchers from Arizona State University explained that when people experience a traumatic event the body releases two major stress hormones: norepinephrine and cortisol. In the brain, norepinephrine functions as a powerful neurotransmitter or chemical messenger that can enhance memory. Previous studies have shown that cortisol can also have a powerful effect on strengthening memories.

The study included nearly 40 women who viewed 144 images from the International Affective Picture Set. This set is a standardized picture set used by researchers to elicit a range of responses, from neutral to strong emotional reactions, upon view.

The researchers gave each of the study participants either a dose of hydrocortisone to stimulate stress or a placebo just prior to viewing the picture set. Each woman then rated her feelings at the time she was viewing the image, in addition to giving saliva samples before and after. One week later, a surprise recall test was administered.

The research team found that negative experiences are more readily remembered when an event is traumatic enough to release cortisol after the event, and only if norepinephrine is released during or shortly after the event.

"This study provides a key component to better understanding how traumatic memories may be strengthened in women," researcher Sabrina Segal said in a statement. "It suggests that if we can lower norepinephrine levels immediately following a traumatic event, we may be able to prevent this memory enhancing mechanism from occurring, regardless of how much cortisol is released following a traumatic event."

Segal said further studies are needed to explore to what extent the relationship between these two stress hormones differ depending on whether you are male or female, particularly because women are twice as likely to develop disorders from stress and trauma that affect memory, such as in Posttraumatic Stress Disorder.