ABSTRACT
ABSTRACT Introduction Gratitude has several implications. Over time, a logical relationship has been established between gratitude and well-being. In addition, researchers aimed to establish associations between gratitude and other factors of positive feelings using scientific methods. We conducted a systematic review and meta-analysis of interventions to develop gratitude and its benefits to human beings. Objective This study aimed to evaluate and quantify the available scientific evidence on interventions to acquire knowledge on gratitude as a quantifiable causal factor of benefit to human beings. Methods A systematic literature search was conducted to identify studies that investigated the effects of gratitude interventions. MEDLINE, Embase, and Central Cochrane databases were searched in addition to gray (Google Scholar) and manual search. Two authors independently evaluated the titles and abstracts, and selected the studies that met the inclusion criteria. The searches were conducted between January and July 2022. Results Sixty-four randomized clinical trials were included. The meta-analysis demonstrated that patients who underwent gratitude interventions experienced greater feelings of gratitude, better mental health, and fewer symptoms of anxiety and depression. Moreover, they experienced other benefits such as a more positive mood and emotions. Conclusion The results demonstrate that acts of gratitude can be used as a therapeutic complement for treating anxiety and depression and can increase positive feelings and emotions in the general population. Prospero database registration: (www.crd.york.ac.uk/prospero) under the number CRD42021250799.