A University of Haifa study on rats has found that giving medical marijuana to those with symptoms of post-traumatic stress disorder can provide significant relief. In addition, a pilot study on 20 Israel Defense Forces veterans and others with PTSD that was recently launched in various psychiatric hospitals is promising, but a full clinical trial has not yet been approved by the Health Ministry, The Jerusalem Post has learned.
The use of cannabinoids (marijuana) could help PTSD patients, said the university's Dr. Irit Akirav of the psychology department learning and memory lab. "The results of our research should encourage psychiatric investigation into using cannabinoids" in such patients, she wrote in an article just published in the prestigious Journal of Neuroscience. The study was carried out by research student Eti Ganon-Elazar under Akirav's supervision.
PTSD is an anxiety disorder that may appear after exposure to one or more traumatic events in which the victim was threatened by or suffered significant physical harm. Symptoms include re-experiencing original trauma through flashbacks or nightmares; avoidance of stimuli associated with the trauma; and increased arousal such as anger, difficulty falling or staying asleep and hypervigilance. PTSD researchers at the Hadassah University Medical Center have suggested in the past that there is a short "window of opportunity" to treat PTSD with talk therapy and/or drugs soon after the traumatic event and that if it is missed, success rates are significantly lower.
Dr. Yehuda Baruch, director of the state Abarbanel Mental Health Center and delegated by the Health Ministry to be in charge of approvals for medical marijuana, told the Post on Wednesday that so far, 50 PTSD victims over the age of 30 have been chosen for a clinical trial, but it has not yet received official approval. "While it is too early to know the verdict of the pilot study, I think medical marijuana treatment for PTSD is promising," said the psychiatrist.
Baruch added that demand for medical marijuana is increasing all the time. At present, there are 1,048 Israelis suffering from chronic pain from various neurological and oncological diseases who have been admitted to the program, and Baruch receives about 1,000 new requests annually.
Akirav said that between 10 percent to 30% of people who experience a traumatic event develop PTSD, and that if untreated, suffering can continue for months and even years. It is a relatively common condition in Israel due to terror attacks, wars and Holocaust survivors.
The University of Haifa study used a synthetic form of marijuana, which has similar properties to the natural plant, and a rat model, which presents similar physiological responses to stress to that of humans. The rats were exposed to a mild electric shock in a cage colored white on one side an black on the other. When they moved from the white side to the black, they got the shock. Subsequently, they refused to go to the black area voluntarily, but a few days later after not receiving further electric shocks in the black area, they learned that it is safe again and moved there without hesitation. Next, a second group of rats were placed on a small, elevated platform after receiving the electric shock, which added stress to the traumatic experience. These rats abstained from returning to the black area in the cell for much longer, which shows that the exposure to additional stress does indeed hinder the process of overcoming trauma, the researchers explained.
In the third stage of the research, yet another group of rats were studied
when exposed to the traumatic and additional stress events. However, just before being elevated on the platform, they received an injection of synthetic marijuana in the amygdala area of the brain - a specific area known to be connected to emotive memory. These rats agreed to enter the black area after the same amount of time as the first group - showing that the synthetic marijuana cancelled out the symptoms of stress. Giving the shots over a period of time, they found that regardless of when exactly the injection was administered, it prevented the surfacing of stress symptoms. The team also found that synthetic marijuana prevents increased release of the hormone that the body produces in response to stress. Hebrew University Prof. Raphael Mechoulam, who discovered tetrahydrocannabinol (THC), the active ingredient in marijuana, told the Post that the University of Haifa research team's work was "outstanding. Patients using marijuana indeed report positive effects - mainly improvement of sleep, with no hallucinations in many cases."
He added that a German team has reported that in mice, marijuana is key in the process of forgetting unpleasant memories, while a Canadian group that tested Nabilone, a synthetic drug whose action is similar to that of THC, found excellent results when testing soldiers with PTSD.