Date of Award


Degree Type


Degree Name

Doctor of Philosophy in Psychology


Clinical Psychology



First Advisor

Lynda Stein


Research demonstrates a positive impact of Peer Based Recovery Support Services (PBRSS) facilitated by peer leaders with lived experience of a Substance Use Disorder (SUD) and/or mental health problems, and who are in stable recovery. The purpose of this study was to investigate PBRSS, their impact on client outcomes (e.g., substance use, health), and the factors (e.g., self-efficacy, perceived relationship with and helpfulness of peer leader) which mediate the relationship between these services and outcomes while controlling for important socio-demographic information (e.g., age). Data were collected across 58 sites within 25 agencies that provide PBRSS delivered by certified peer leaders in Rhode Island. Structural Equation Modeling using Cross-Lagged Panel Models was used to test 12 longitudinal mediational models in a sample of N = 412. After strict alpha correction (p = .00417), most results in this study were non-significant. However, several findings indicated that constructs were significantly related across time in all models (e.g., self-efficacy at time one significantly predicted self-efficacy at time two), while many point-in-time associations were also significant (e.g., number of services received was positively related to relationship/helpfulness of peer leaders at both time one and two). Better peer leader relationship/helpfulness at time one significantly predicted a lower number of services received at time two, while receiving more services at time one significantly predicted better peer leader helpfulness/ relationship at time two. Being older significantly predicted a worse overall health at time two in some models. No mediational effects were found.

Available for download on Monday, January 19, 2026