Affect mediates the influence of the "Three Good Things" intervention on depression and well-being

The "Three Good Things" is a self-administered positive psychological intervention that is effective in reducing depressive symptoms and improving well-being; however, there is still little known about its possible underlying mechanisms. I examined the efficacy of the Three Good Things intervention and investigated the mediating role of positive and negative affect in the intervention's effect on depressive symptoms and subjective well-being. Participants were undergraduate students randomly assigned to either the intervention group (n = 128), who participated in a 16-week trial of the intervention and completed assessment measures, or to the control group (n = 121), who completed assessment measures but not the intervention. The three time points for assessment were Week 1 (baseline), Week 8 (Time 1), and Week 16 (Time 2). The results show that levels of depression and negative affect were lower in the intervention group than in the control group at Time 2, whereas positive affect and subjective well-being were higher. Thus, the intervention can reduce depression and promote well-being by reducing negative affect and improving positive affect.