Scientists at the University of Iowa and the University of Toledo have shown that briefly breathing carbon dioxide makes fear memories more susceptible to modification. Their studies in mice suggest an approach that might improve the effectiveness of exposure therapy in humans affected by post-traumatic stress disorder (PTSD).
Normal fear is an important evolutionary mechanism that can protect animals, including humans, from dangerous situations. But intense fear memories can be incapacitating when they are triggered by unrealistic threats or when the danger no longer exists.
PTSD is a relatively common disorder resulting from debilitating fear memories. According to the National Institute of Mental Health, almost 8 percent of Americans will experience PTSD at some point in their lives. Therapies that diminish excessive fear memories could potentially provide a much-needed way to treat PTSD.
“The discoveries provide basic insight into the modification of traumatic memories, a major goal for treating PTSD,” says Michael Welsh, MD, director of the Pappajohn Biomedical Institute at the UI, a professor of internal medicine in the UI Carver College of Medicine, and a Howard Hughes Medical Institute investigator.