The war in Iraq is drawing to a close. But for many servicemen and women, the conflict is far from over. Haunted by images of roadside bombs, ambush attacks and firefights, military personnel suffering from Post Traumatic Stress Disorder (PTSD) are forced to relive their most horrifying wartime experiences.
The severe anxiety disorder is estimated to afflict 11 percent of returning Afghanistan veterans and 20 percent of soldiers who fought in Iraq, according to the U.S. Department of Veterans Affairs. Symptoms include flashbacks, an excessive startle response, depression, anxiety and sleep disorders.
To lessen the time it takes for PTSD patients to recover from these debilitating ailments, University of Texas at Austin psychology professors Michael Telch and Francisco Gonzalez-Lima, along with their team of researchers, are pairing a memory-enhancing drug with prolonged exposure therapy.
In prolonged exposure therapy, patients repeatedly recount the memory of the traumatic event. As therapy progresses, the fear of the memory weakens and patients begin to feel more in control of their emotions and their lives in general. Typically about two thirds of PTSD patients treated with prolonged exposure therapy during 10 90-minute sessions no longer exhibit PTSD.
"There is now compelling scientific evidence demonstrating exposure therapy to be effective in the treatment of PTSD, however there is still a clear need to make the treatments work better and faster," says Telch, professor of psychology.
The researchers believe the FDA-approved compound USP methylene blue, which significantly improved fear extinction in rats in an earlier study conducted in the Gonzalez-Lima Lab, will help strengthen the extinction of fear that occurred during prolonged exposure therapy sessions.
As part of the animal study, Gonzalez-Lima and his research team subjected rats to fearful stimuli during a fear extinction session, then administered USP methylene blue. With the drug,
Gonzalez-Lima said they were able to significantly reduce the rats' fears.
"USP methylene blue is an effective therapeutic intervention in animal models of neuropsychiatric disorders, including PTSD," says Gonzalez-Lima, professor in the Department of Psychology and the College of Pharmacy. "The drug's potential to enhance fear extinction may serve as an adjunct to psychotherapy, as a novel way to improve exposure therapy outcome for anxiety disorders."
After successfully achieving positive results from the rat study, the researchers are taking the next important step by testing whether the drug enhances fear extinction in PTSD patients undergoing exposure therapy.
As part of the study, conducted in Telch's Laboratory for the Study of Anxiety Disorders and at two other sites, the University of Washington and the University of Pennsylvania, respondents take a placebo pill or a dose of the drug after a therapy session. The researchers theorize the patients taking the medication will recover faster and better in only six daily one-hour sessions.
"We are hopeful the promising findings of Dr. Gonzalez-Lima and others, showing that USP methylene blue enhances the extinguishing of fear in rodents, will carry over to exposure therapy in humans, and thus provide a safe and convenient method for enhancing exposure therapy for PTSD and possibly other anxiety disorders as well," says Telch.
Post-traumatic stress symptoms often emerge immediately after traumatic experiences. For most, these symptoms subside on their own soon after the trauma. However, about 30 percent of trauma victims go on to develop PTSD in which their trauma memories continue to haunt them and create significant distress and life impairment for months or years after the event.
As patients repeatedly recount a frightening event in prolonged exposure therapy, they begin to look at the memory differently. The researchers predict USP methylene blue will expedite this process, saving the patients both time and medical expenses.
"We predict that patients given a memory boost with USP methylene blue immediately after therapy sessions will make more lasting gains during therapy than those who do not take the medication," Telch says.
Taken orally, the chemical properties of USP methylene blue affect regions of the brain, such as those mediating fear extinction.
"Methylene blue easily crosses the blood-brain barrier and accumulates inside activated brain cells," Gonzalez-Lima says. "Once inside the neurons, the substance zooms in on mitochondria the power house of the cell to keep it active and enable the brain cells to keep processing the memory."
The researchers are recruiting participants for the study, which is a clinical trial funded by the National Institute of Mental Health, conducted in the Laboratory for the Study of Anxiety Disorders at The University of Texas at Austin. For more information about participating in the study, call 512-404-9118.