Prolonged Exposure (PE) therapy is the most widely researched behavioral therapy for posttraumatic stress disorder (PTSD) and has shown to be an effective treatment. However, recovery rates have not been as high among military personnel and veterans as with civilians. Massed PE, delivered during a shortened period of 10 daily sessions over two weeks, has shown to be more effective and better received among this population than standard treatment, with fewer patients dropping out.

PE therapy can be challenging because, to help patients process and gain control over their traumatic memories, it requires them to retell the story of their traumatic experience, a part of the therapy called imaginal exposure. PE also involves gradual exposure to real-world situations that are safe but that trigger memories or feelings associated with the trauma. The related, temporary increase in physiological stress can make the therapy difficult to tolerate and potentially decrease efficacy.

Other research has demonstrated improvements in PTSD symptoms from a stellate ganglion block (SGB), an injection of a local anesthetic into a group of nerves located on the side of the throat, which are part of the sympathetic nervous system. But the results were temporary, requiring subsequent SGB injections to reduce the symptoms again.

Pilot study shows potential for improved outcomes

In a recent pilot study, STRONG STAR investigators led by Alan L. Peterson, PhD (Lt Col, USAF Ret.), of The University of Texas Health Science Center at San Antonio, combined massed PE with SGB. This combination resulted in the greatest reduction in PTSD symptoms seen in any of the 25 clinical trials conducted by STRONG STAR and the Consortium to Alleviate PTSD to date. And the symptom reductions lasted over time.

The investigators believe they achieved these results because the SGB reduced physiological arousal, allowing patients to engage more productively during their therapy sessions. Participants reported lower physiological distress but were still able to access their emotions during the imaginal exposure and post-exposure processing.

Further testing with a randomized clinical trial

Dr. Peterson’s team will now test this combined treatment approach with 140 patients with PTSD diagnosis recruited from military treatment facilities at Fort Cavazos (formerly Fort Hood) and at Joint Base San Antonio-Fort Sam Houston, both in Texas.

All patients will receive massed PE therapy, but only half will receive a real SGB injection. The other half will receive a placebo injection for purposes of the study. However, following their study assessment one month posttreatment, those who received a placebo will be offered an SGB.

Expected outcomes and ultimate benefits

The investigators hypothesize that the patients receiving the SGB with massed PE will show greater reductions in PTSD symptoms than those receiving the placebo. They also believe that those receiving the SGB will experience less physiological arousal during imaginal exposure, compared to the placebo group, and that those decreases will be associated with greater reductions in PTSD symptoms.

They believe that if the study is successful, it could not only improve mental health outcomes for individuals, but also potentially improve long-term retention of active duty military personnel, decrease suicide rates among service members, and decrease medical costs associated with treating PTSD and comorbid conditions.