Table 1.
Summary of articles related to gratitude studies.
| First author (year) | Study design | Type participant | N | Mean Age (SD) | % Male | Gratitude measure(s) | Intervention | Time frame | Summary of findings |
|---|---|---|---|---|---|---|---|---|---|
| Redwine et al. (2016) | Randomized blinded trial | Patients with stage B heart failure | 70 | 66(7.58) | 95% | GQ6 | Gratitude journal | 8 weeks | Gratitude was associated with lower levels of inflammatory biomarkers, such as CRP, TNF-α, IL-6 and sTNFr1, and higher parasympathetic heart rate variability. |
| Moieni et al. (2019) | Randomized blinded trial | Healthy middle-aged women | 76 | 43(4.70) | 0% | GQ6 | Writing aimed at inducing gratitude | 6 weeks | Gratitude interventions had no direct effect on inflammatory markers. Gratitude interventions were correlated with a decreased percentage of monocytes producing proinflammatory IL-6 and TNF- α through the habit of increased support-giving. |
| Schache et al. (2020) | Randomized blinded trial | Type 1 diabetes patients | 80 | NR | NR | GQ6 | Gratitude journal | 8 weeks | Gratitude interventions can help improve glucose control in patients with type 1 diabetes. |
| Wolfe and Patterson (2017) | Randomized blinded trial | Undergraduates | 140 | 20 (6.93) | 0% | – | Gratitude listing | 2 weeks | Gratitude interventions were demonstrated to effectively reduce eating disorders, lower the risk of depressive symptoms and reduce negative psychological outcomes. |
| Fritz et al. (2019) | Randomized blinded trial | Undergraduates (1) and high school students (2) | 327(1) 1017(2) | (1):19(1.30) (2):NR | 24%(1) NR (2) | GQ6 | Gratitude letter | (1):2 weeks (2):4 weeks | Gratitude interventions can improve eating behaviors. |
| Sultan et al. (2018) | Randomized blinded trial | Patients with CHD | 40 | 48.64 | 100% | GQ6 | An intervention that focuses on enhancing positive psychological attributes | 8 weeks | Higher levels of gratitude and lower CHD symptoms were observed in the positive psychological intervention group. Positive psychology interventions can facilitate gratitude and help reduce the risk of CHD. |
| Jackowska et al. (2016) | Randomized blinded trial | Young women | 119 | 26 | 0% | – | Gratitude journal | 2 weeks | Gratitude interventions are associated with a decrease in diastolic blood pressure and improvements in depression and sleep quality when compared with the control. |
| Digdon and Koble, (2011) | Randomized blinded trial | Undergraduates | 41 | 23 (6.11) | 22% | – | Positive events journaling | 1 week | Improvements in sleep quality and quantity and reductions in the level of pre-sleep arousal were observed after the gratitude intervention. |
| O’Connell et al. (2017) | Randomized blinded trial | Mainly young adult sample | 192 | 27(12.60) | 33% | GQ6 | Reflective behavior – reflective only – control journaling | 3 times a week for 3 weeks | Gratitude interventions had great potential in decreasing negative feelings and reducing their adverse effects on health. |
| Salces-Cubero et al. (2019) | Randomized blinded trial | Elderly | 124 | 69(7.78) | 40% | – | Positive activities available to train gratitude | One week before intervention, 1 week after intervention, and a month after intervention completion | Gratitude interventions were associated with decreases in negative mental states and increases in positive psychological states, which can enhance patients’ subjective well-being and life satisfaction. |
| Yang et al. (2018) | Randomized blinded trial | Prisoners | 144 | NR | NR | – | Gratitude journal and group seminars | 6 weeks | Gratitude interventions can decrease negative mental states and significantly enhance the subjective well-being of prisoners. |
| Cheng et al. (2015) | Randomized blinded trial | Medical workers | 102 | NR | 35% | – | Gratitude journal | Twice a week for 4 weeks | Gratitude interventions were correlated with decreased self-reported depression symptoms and perceived stress. |
| Ramírez et al. (2014) | Randomized blinded trial | Elderly | 46 | 71 (7.06) | 65% | – | Gratitude letter | Once a week for 9 weeks | Gratitude interventions can significantly reduce depressive symptoms and anxiety and enhance subjective well-being and life satisfaction. |
| Watkins et al. (2015) | Randomized blinded trial | College students | 129 | NR | 29% | SGRAT | Gratitude journal | 6 weeks | Gratitude interventions can reduce depressive symptoms and enhance subjective happiness over the course of 5 weeks after the intervention. |
| Southwell and Gould, (2017) | Randomized blinded trial | Persons with depression or anxiety disorders | 109 | 34(10.80) | 12% | GQ6 | Gratitude journal | 3 weeks | Participants with a high level of gratitude have lower scores on sleep difficulties, anxiety and depression. |
| Hazlett et al. (2021) | Randomized blinded trial | Healthy women | 61 | 43(4.80) | 0% | – | Writing aimed at inducing gratitude | Once a week for 6 weeks | Gratitude interventions may decrease sympathetic nervous system activity by reducing amygdala reactivity and activating the ventral striatum and diaphragm area. |
| Kyeong et al. (2017) | Randomized blinded trial | Healthy people | 32 | 23 (2.50) | 47% | – | Gratitude and resentment interventions | 5 min | The average heart rate during the gratitude intervention was lower than the average heart rate during the resentment intervention |
| Rash et al. (2011) | Randomized blinded trial | Adult sample | 56 | 23 (3.00) | 54% | GQ6 | Gratitude contemplation | Twice a week for 4 weeks | Gratitude practices can reduce stress, increase cardiac coherence and result in more ordered ECG waveforms and greater physiological coordination. |
| Matvienko-Sikar and Dockray, (2017) | Randomized blinded trial | Pregnant women | 46 | 34(3.04) | 0% | GDP | Gratitude journal | Four times a week for 3 weeks | The gratitude intervention group showed lower cortisol and stress levels in wakefulness and sleep during pregnancy compared to the control group that received conventional therapy. |
ACS, acute coronary syndrome; CHD, coronary heart disease; ET-1, endothelin-1; GDP, the Gratitude during Pregnancy Scale; GQ6, gratitude questionnaire 6; GRAT, gratitude, resentment, and appreciation test; NR, not reported; SGRAT, short gratitude, resentment, and appreciation test; sICAM-1, soluble intercellular adhesion molecule-1.