【心理の改善効果があるエビデンス（科学的証拠）一覧】

・Otto, Amy K., et al. "Effects of a randomized gratitude intervention on death-related fear of recurrence in breast cancer survivors." Health Psychology 35.12 (2016): 1320.

・Redwine, Laura S., et al. "Pilot randomized study of a gratitude journaling intervention on heart rate variability and inflammatory biomarkers in patients with stage B heart failure." Psychosomatic medicine 78.6 (2016): 667-676.

・O’Connell, Brenda H., Deirdre O’Shea, and Stephen Gallagher. "Examining psychosocial pathways underlying gratitude interventions: A randomized controlled trial." Journal of Happiness Studies 19.8 (2018): 2421-2444.

・Davis, Don E., et al. "Thankful for the little things: A meta-analysis of gratitude interventions." Journal of counseling psychology 63.1 (2016): 20.