Cannabis could help treat people with PTSD, researchers say. Reuters

Providing trauma patients with medical marijuana shortly after the event could help prevent post-traumatic stress disorder (PTSD), researchers have said.

In a study on rats, scientists at the University of Haifa in Israel found that administering synthetic marijuana, or cannabinoids, helped to prevent PTSD symptoms caused by both the trauma and trauma reminders.

It is estimated that about 3% of the population will experience PTSD at some point in their lives, with combat soldiers, prisoners and victims of crime particularly at risk.

Researchers Nachshon Korem and Irit Akirav said: "The importance of this study is that it contributes to the understanding of the brain basis of the positive effect cannabis has on PTSD and thus supports the necessity to perform human trials to examine potential ways to prevent the development of PTSD and anxiety disorders in response to a traumatic event."

Published in the journal Neuropsychopharmacology, the authors note that common phenomenon of PTSD is the 'trauma reminder' – which evokes the memory of the traumatic experience.

Previously, Akirav had found that the use of marijuana within a short time frame after a traumatic event helped to reduce PTSD symptoms in rats. In their latest study, the team looked at whether cannabinoids could reduce the symptoms of PTSD following a trauma reminder.

Findings showed that rats treated with marijuana showed no PTSD symptoms compared to the control group that did not receive the drug. The treated rats also showed better results than those that had been given an antidepressant.

"In other words, cannabis made the effects of trauma reminders 'disappear'," the researchers said in a statement, adding they believe the cannabinoids prevented the brain from forming and saving traumatic memories.

"The findings of our study suggest that the connectivity within the brain's fear circuit changes following trauma, and the administration of cannabinoids prevents this change from happening. This study can lead to future trials in humans regarding possible ways to prevent the development of PTSD and anxiety disorders in response to a traumatic event," they said.