Post Traumatic Stress Disorder (PTSD) is an anxiety disorder which is brought about when a person has experienced a traumatic, frightening or distressing event in their life. Characterized by flashbacks and nightmares, the symptoms of the disorder can continue for a number of months, years, or remain with the person for the rest of their life.
Chronic stress is also believed to be responsible for inflammation in the central nervous system, which exacerbates the symptoms of mental health disorders and subsequently can result in PTSD.
Currently, there are only two FDA-approved medications and psychotherapy practices for PTSD, including cognitive and exposure therapies. Cassandra Moshfegh (a research assistant in Paul Marvar's laboratory at the George Washington University) and her colleagues wanted to see if orange essential plant oil would have any effect on combating the symptoms of PTSD. Essential plant oils have been used for therapeutic purposes since they are naturally produced, and those of an orange are usually extracted from the peel.
To test this, the researchers took two groups of mice in order to analyze their fear memory and immune cell activation. Known as "Pavlovian Fear Conditioning" (a behavioral mouse model) their aim was to see how orange essential oil worked when the mice were exposed to stressful situations.
Using this model, the researchers paired up an audio tone with a negative action (such as a shock to the foot) in order to produce a fearful response from the mice. Consequently, the mice developed an association of fearfulness with the tone (which corresponds to the fear of being shocked) and typically froze up. As with a person, this kind of response gradually fades with time.
After this, Moshfegh and her team divided the mice up into three groups of twelve. The first of these were exposed to the audio tone, twelve more were given water and fear conditioning, and the other mice were given orange essential oil by inhalation 40 minutes prior to and after the fear conditioning.
When they ran the experiments, they noted that the mice who had been given the orange essential oil were much less likely to display fearful symptoms such as freezing up. They also demonstrated a significant decrease in the immune cells linked to the "biochemical pathways" that are associated with PTSD.
The study shows promise and Moshfegh notes that, "Relative to pharmaceuticals, essential oils are much more economical and do not have adverse side effects. The orange essential plant oil showed a significant effect on the behavioral response in our study mice."
She now wants to see how this could possibly be used to help reduce the symptoms of fear and stress in sufferers of PTSD.