Lavender aroma moderates endocrine response to an acute psychological stressor but does not impact on subjective measures of mood and demand

This study investigated the effect of the aroma of lavender essential oil on levels of salivary cortisol and self-reported mood following completion of a psychologically stressful Multi-Tasking Framework (MTF) that comprises a number of cognitive and psychomotor performance measures. Using a repeated measures design, thirteen volunteers were exposed to lavender aroma and no aroma in a counterbalanced design. During each testing session participants performed the MTF for 10 minutes. Change in self reported levels of alertness, calmness and contentedness were assessed using the Bond-Lader visual analogue scales. Samples of saliva were collected before and after completion of the MTF and assayed for cortisol levels. Data analysis revealed that in comparison to the no aroma control, lavender ameliorated increases in the level of salivary cortisol induced following completion of the MTF. However, lavender aroma did not impact upon changes in self reported mood, or perceptions of how taxing the task was. Performance on the MTF as measured by total score obtained was not found to be affected significantly, although the effect size found was of the order reported previously for the impact of lavender on cognition.