By ALEXANDRA THOMPSON HEALTH REPORTER FOR MAILONLINE
Stress can cause people to misidentify cues as dangerous for self-defense
This may explain why PTSD symptoms are worse during periods of stress
As well as why repeated stress and trauma during war increases the risk of PTSD
Experts believe these findings could help to treat PTSD symptoms via prevention
Humans are thought to have learned to identify dangerous scenarios for self-defense, however, certain circumstances can cause people to misidentify such cues.
Researchers found people respond with fear when their stress levels are high.
Suzannah Creech, associate professor of psychiatry at the University of Texas, who was not involved in the study, said: 'These findings provide important laboratory data that helps explain why PTSD [post-traumatic stress disorder] symptoms are often exacerbated during times of stress, and how repeated stress and trauma in the battlefield may lead to increased risk for PTSD.'
Experts believe the findings could aid PTSD treatment.
How the study was carried out
Researchers from the universities of Texas, New York and McGill played healthy participants two notes, with one being followed by a shock. The shock was described as irritating but not painful.
The participants were asked about their experience of the shock.
Half of the participants then had their arm placed in an ice bath to raise their levels of the stress hormone cortisol. The remaining participants' arms were put in room temperature water.
All of the participants were then replayed the same two notes as before.
This was carried out immediately after receiving the shock and 24 hours later.
Stress heightens fear
Results reveal stress heightens people's fear response.
It also hindered the participant's ability to identify the note associated with the earlier shock.
Professor Lead author Professor Joseph Dunsmoor from the University of Texas, said: 'The human mind uses cues to danger learned over time for self-defense, but certain circumstances can cause people to misidentify those cues.
'Our research reveals that stress levels and the amount of time since an adverse event promote this type of overgeneralization.'
The non-stressed participants had only slightly raised fear responses and were able to correctly identify the note-associated shock.
These results only occurred in the experiment taking place 24 hours after the initial shock. It is unclear why stress is associated with a false sense of danger or why the findings did not occur immediately after the shock.
The outcomes were published in the journal Proceedings of the National Academy of Sciences.
Professor Creech said: 'These findings provide important laboratory data that helps explain why PTSD symptoms are often exacerbated during times of stress, and how repeated stress and trauma in the battlefield may lead to increased risk for PTSD.
'The research may help improve PTSD treatment outcomes for veterans in part by helping us understand how we may be able to prevent it in the first place.'
Read more: http://www.dailymail.co.uk/health/article-4771110/Stress-makes-people-sense-danger-harmless-situations.html#ixzz4pGuIQ2G3