Effects of a Low-Intensity Gratitude Intervention on Psychological Well-Being Outcomes: A Randomized Controlled Trial in a Sample of Japanese Young Adults

Gratitude interventions have been shown to improve subjective well-being but results often depend on cultural context, with non-WEIRD populations typically benefitting less than WEIRD populations (Western, Educated, Industrialized, Rich, Democratic). This study examined the effects of a low-intensity gratitude intervention on psychological well-being in 404 Japanese young adults. Hypotheses and methods were preregistered. Analyses focused on 138 participants with moderate/low well-being and no depression or anxiety symptoms at baseline. Results showed that participants in the gratitude intervention group experienced increases in Psychological Well-Being Scale Autonomy, with effects lasting at least 3 months. Additionally, while both groups showed increased mean scores on the Mental Health Continuum-Short Form, effects in the control group receded after 3 months but persisted in the gratitude intervention group. These findings suggest that gratitude interventions can have lasting effects on psychological well-being, even in cultural contexts where such interventions are less likely to influence subjective well-being.