Validation of Best-Self PPI: A New Positive Psychological Intervention Targeting Self-Referential Processing

Author

Bryant M. Stone, Southern Illinois University CarbondaleFollow

Date of Award

8-1-2023

Degree Name

Doctor of Philosophy

Department

Psychology

First Advisor

Gilbert, David

Second Advisor

Drake, Chad

Abstract

Depression is a common psychopathology that causes affective, behavioral, and cognitive dysfunction and is present across cultural identities. To reduce the dysfunction and treat the symptoms that arise from depression, researchers have created positive psychological interventions (PPIs), which are empirically supported interventions that cause a positive change by targeting a positive variable. In the current study, I created a new PPI, the Best-Self PPI, that draws from elements of optimism, coherence, and character strengths PPIs. Specifically, I hypothesized that the Best-Self PPI would work by positively biasing self-referential processing, which may predict depression and psychological well-being. Participants (n = 133) were undergraduates between the ages of 18 and 32 (M = 19.97, SD = 1.66). Participants were primarily female (n = 85; 63.91%) and White (n = 87; 65.41%) and completed either the Best-Self PPI or wrote about a childhood memory (T1, +0 Days), completed the Self-Referential Encoding Task (T2 +1 Day), and then completed a set of outcome measures (T3, +8 Days). Although the intervention appeared to have no effect on depression, well-being, or affect compared to the control group, I found that: 1) self-referential processing bias partially mediates the relationship between self-critical rumination and depression, 2) self-referential processing bias and state self-esteem fully explain the relationship between self-critical rumination and depression, and 3) self-esteem fully explains the relationship between self-critical rumination and psychological well-being. The results provide new empirical evidence for why some interventions may reduce depression and promote psychological well-being through changes in self-evaluations. I encourage researchers to use the evidence in the current study that modifying self-referential processing and state self-esteem may affect depression and psychological well-being to improve existing interventions and create new interventions to promote psychological well-being above and beyond the elimination of suffering.