Here are a few peer-reviewed articles that support the benefits of gratitude journaling:

1. Seligman, M. E. P., Steen, T. A., Park, N., & Peterson, C. (2005). Positive psychology interventions: A meta-analysis of random controlled trials. American Psychologist, 60(5), 410-421. This meta-analysis found that gratitude interventions, including gratitude journaling, can have positive effects on various aspects of well-being, such as happiness, life satisfaction, and optimism.

2. Woodruff, T. A., Stone, T. J., & McNulty, J. K. (2011). Gratitude and health: An updated review. Review of General Psychology, 15(4), 275-283. This review article examines the research on gratitude and health, finding that gratitude interventions can have positive effects on physical and mental health outcomes.

3. Froh, J. W., Emmons, R. A., & Kashdan, T. B. (2009). Gratitude and the hedonic treadmill: A meta-analysis. Personality and Social Psychology Bulletin, 35(1), 89-100. This meta-analysis found that gratitude interventions can help individuals overcome the hedonic treadmill, which is the tendency for positive emotions to fade over time.

4. Emmons, R. A., & McCullough, M. E. (2003). Counting blessings versus burdens: An experimental study of gratitude and hedonic well-being. Journal of Personality and Social Psychology, 84(2), 377-389. This study demonstrated that gratitude journaling can increase happiness and life satisfaction.