Within the branch of positive psychology, happiness studies may be one of the hottest topics. After all, who doesn’t want to be happy? Several decades of happiness research, including books, articles, and websites devoted to the topic, have uncovered its unique qualities. Certainly, happiness can easily be connected to overall psychological well-being. But, what about its connection to physical health? There is a solid foundation of prior research linking happiness and health outcomes. However, experimental studies of non-depressed community members are lacking.
Kushlev and colleagues launched a randomized controlled trial to address this gap. These researchers chose to induce happiness via a positive psychology intervention (PPI) and then to measure outcomes for subjective and objective health indicators.
This study deployed a longitudinal design to identify if inputs from the PPI would improve psychological and physical well-being up to 6 months after program completion.
Study Design:
A total of 155 participants between the ages of 25 and 75 were recruited for the study. These participants were divided into four groups from two different geographical areas. Participants in the intervention groups (77 people) received either in-person or online training in PPI. Control group participants were placed on a wait-list and received no intervention.
The PPI (ENHANCE) is a 12-week program consisting of a weekly hour-long group session followed by a writing assignment and a behavioral application exercise. The ENHANCE program promotes “self-affirmation, mindfulness, gratitude, positive social interactions, and prosocial behavior” (p. 5).
Prior to beginning the study, all participants completed baseline health and well-being assessments. Anyone scoring as moderately depressed was excluded from participation.
During the study, all participants completed weekly assessments measuring self-reported well-being (affect, life satisfaction, meaning in life) and health status. At three intervals, BMI and blood pressure were assessed, which served as objective assessments of health.
Key Findings:
- As a result of the PPI, “participants grew more satisfied with their lives and reported increasingly higher positive affect and lower negative affect throughout the course of treatment, whereas control participants experienced little change” (p. 8)
- Participants in the PPI group experienced more meaning in life compared to the control group
- The PPI group reported fewer sick days compared to the control group, however, there were no group differences on objective health indicators (BMI and blood pressure).
In summarizing the study’s findings, the authors noted: “Over the course of the program, treatment participants reported increasing levels of subjective well-being compared with control participants; week-to-week changes in subjective well-being over the course of treatment, in turn, predicted subsequent changes in the number of sick days reported by participants” (p. 10).
As positive psychology interventions are developed and fine-tuned, they carry the potential to make positive changes in the subjective well-being of participants. These changes can even translate to improved physical well-being, as indicated by reduced sick days in the present study.
Kushlev, K., Heintzelman, S. J., Lutes, L. D., Wirtz, D., Kanippayoor, J. M., Leitner, D., & Diener, E. (2020). Does happiness improve health? Evidence from a randomized controlled trial. Psychological Science, 31(7), 807-821.
©Jennie Dilworth, Ph.D