Relationship of laughter with mood/emotion and cortisol and dehydroepiandrosterone (DHEA) secretion: intervention study - Laughter, mood/emotion, and cortisol/DHEA

Fujisawa A, Ota A, Matsunaga M, Li Y, Kakizaki M, Naito H, Yatsuya H. Effect of laughter yoga on salivary cortisol and dehydroepiandrosterone among healthy university students: A randomized controlled trial. Complementary Therapies in Clinical Practice 2018 (in press) Objective: To examine whether laughter yoga (LY), i.e., simulated laughter, alters cortisol and dehydroepiandrosterone (DHEA) levels and cortisol/DHEA (C/D) ratios. Methods: In a randomized controlled trial, 120 healthy university students were allocated to experiencing LY, watching a comedy movie (spontaneous laughter), or reading a book. Salivary cortisol and DHEA levels were measured immediately before, immediately after, and 30min after the intervention. Results: Cortisol levels and C/D ratios significantly decreased by time in the LY and comedy movie groups. Significant group*time interactions were found between these two groups for cortisol levels and C/D ratios. DHEA levels did not change by time in the LY group. Conclusions: LY decreased cortisol levels and C/D ratios but did not affect DHEA levels. Simulated and spontaneous laughter differently affected the dynamics of cortisol levels and C/D ratios. Effect of spontaneous laughter on the cortisol dynamics lasted longer than that of simulated laughter.