Scott Gerson, MD, PhD, Ayurveda., The Foundation for Holistic Medical Research, Brewster, NY
Decreased alpha-wave activity is known to correlate with states of increased anxiety. This study was designed to analyze the EEG activity elicited by inhaling aromas of 3 different pure essential oils in patients with an established diagnosis of anxiety neurosis. Anxiety level was assessed before and after aromatherapy using the State Trait Anxiety Profile (STAI). Sixty-one subjects (39 female and 22 male) were pre-screened and found to be in satisfactory general health, with no use of central nervous system-affecting drugs within the previous 6 months. The study was double-blinded, randomized, and controlled. Prior to and after administration of the essential oils, patients completed the STAI.
The EEG protocol:
The 3 essential oils evaluated were Neroli (Citrus aurantium), Davana (Artemisia pallens), and Patchouly (Pogostemon patchouli). A device holding 1 cc of oil was positioned 2 cm under the subject's nostrils. EEG’s were scored epoch by epoch by independent neurologists unaware of the nature of the study. Each scoring epoch was 6.67 seconds of EEG recording. Epochs were scored as alpha, beta/theta, delta, or artifactual, respectively, if greater than 50% of the epoch consisted of that activity. The possible STAI scoring range was 20 (maximum anxiety) to 80 (absence of anxiety). The effects of each of the 3 essential oils were compared to baseline (eyes closed, resting comfortably, with normal respirations). When exposed to neroli oil 82% of the subjects (50 of 61) showed a mean increase in alpha activity of 16% (p<0.05). When exposed to davana oil 71% of the subjects (43 of 61) showed a mean increase in alpha activity of 13% (p<0.05). When exposed to patchouly oil 43% of the subjects (26 of 61) showed a mean increase in alpha activity of 9% (p<0.1). STAI values increased by 78% (neroli), 72% (davana), and 28% (patchouly). These results showed that both neroli and davana essential oil aromas increased alpha-wave activity in patients with established anxiety neurosis. These physiological findings correlated with findings of decreased anxiety levels as assessed by the STAI. Patchouly oil was not effective in this regard.