The Effect of Laughter Yoga on Depression and Serotonin Levels in Patients Who Underwent Bariatric Surgery

Background: This study aimed to determine the effect of laughter yoga on depression and serotonin levels in patients who underwent bariatric surgery. Material Method: The research was conducted between December 2018 and April 2022 using a quasi-experimental design with a pretest–posttest control group. The study population consisted of 158 patients who underwent bariatric surgery in the General Surgery Department and were between 6 and 24 months postoperation. The sample size was determined using power analysis, resulting in a total of 62 participants. The laughter yoga group participated in 10 sessions. Depression and serotonin levels were measured both before and after the intervention in both the experimental and control groups. Data were analyzed using descriptive statistics (number, percentage, mean, standard deviation), chi-square test, paired samples t- test, and independent samples t- test. Results: In the laughter yoga group, posttest depression levels significantly decreased compared to pretest levels ( p < 0.05). Posttest depression levels were also significantly lower in the laughter yoga group compared to the control group ( p < 0.05). Although serotonin levels decreased in the laughter yoga group posttest compared to the control group, this difference was not statistically significant ( p > 0.05). Conclusion: Laughter yoga was found to be effective in reducing depression in patients following bariatric surgery. While a decrease in serotonin levels was observed, it was not statistically significant.