Bergamot Inhalation for Anxiety: A Meta Analysis of Randomized, Controlled Clinical Trials
Essential oil inhalation is frequently used to treat anxiety in multiple populations. While multiple clinical trials on this application exist in the scientific literature, findings often conflict. Effect sizes in these studies vary dramatically and some studies do not find that inhalation of bergamot essential oil for anxiety is effective. To address this issue, the Franklin School of Integrative Health Sciences Research Department conducted a meta-analysis on bergamot and anxiety.
"Bergamot Essential Oil for Anxiety: A Meta-Analysis"
When there are not many large studies on a topic, or when studies on a topic begin to find conflicting results, a meta-analysis is used to provide more precision and details on the effects of an intervention. A meta-analysis analyzes data compiled from all of the existing studies on a topic to identify the true effect size of a treatment and to identify any factors that influence whether or not an intervention actually works.
The purpose of this meta-analysis is to determine whether or not inhalation of bergamot essential oil can reduce anxiety as compared to a control group, and to identify factors that explain studies which produce conflicting results.
Studies for this analysis were identified from the scientific literature and from unpublished works during several months in early 2018. Inclusion criteria included studies conducted worldwide which used plain bergamot essential oil as the intervention and anxiety scores as the primary outcome. Anxiety scores were measured objectively through blood pressure and heart rate, and subjectively through the State-Trait Anxiety Inventory (STAI), a validated anxiety measurement. Studies which evaluated blends or other outcomes were excluded from the analysis.
Findings: Bergamot for Anxiety
This analysis included 316 total participants and evaluated the moderator variables of age and underlying source of anxiety. Overall, bergamot essential oil inhalation was found to have a powerful effect on anxiety scores. The overall effect size was over twice the minimum requirement to be classified as "large."
Essential oil inhalation of 10-15 minutes once daily effectively reduced anxiety in stimulated situations and among adults in pre-procedural situations. The underlying cause of anxiety did not play a role in whether or not inhalation was effective. Bergamot essential oil was effective at treating anxiety from all sources. However, age did make a difference in the overall findings. Bergamot essential oil inhalation did not reduce anxiety among pediatric patients experiencing preprocedural anxiety.
Bergamot essential oil can be inhaled using a personal inhalation device or by simply placing a few drops onto a cotton ball or tester strip. Inhalation for anxiety relief can take place once daily for chronic anxiety or a mild anxiety condition. For situational anxiety or acute conditions, it can be used as-needed rather than daily.
This analysis found that inhalation is not effective at reducing anxiety scores for children who are experiencing preprocedural anxiety. A clinical trial conducted by the Franklin School of Integrative Health Sciences was included in this analysis. This study found that bergamot may actually increase the subjective experience of anxiety when used to treat children who have an autism spectrum disorder and are experiencing preprocedural anxiety. These results have been replicated in another study on pediatric populations without ASD.
It is not clear from the existing data why bergamot essential oil does not effectively reduce anxiety in children prior to medical procedures. There is an urgent need for additional research on this subject to identify factors that may contribute to the effects of this oil.
For More Information
The study is currently under peer review for publication.