ENHANCE: Evidence for the efficacy of a comprehensive intervention program to promote subjective well-being.

Building from the growing empirical science of happiness, or subjective well-being (SWB), we have developed a 12-week comprehensive intervention program-Enduring Happiness and Continued Self-Enhancement (ENHANCE)-to increase SWB and enable a thorough examination of the mechanistic processes of program content and administrative structure for SWB change over time. In a randomized controlled trial, participants (N = 155; 55 using the in-person format, 100 online format) were randomly assigned to participate in ENHANCE or to a waitlist control condition. All participants completed assessments of SWB, including non-self-report measures, and process variables at baseline, posttest, and follow-up (3 months). We found evidence supporting the efficacy of ENHANCE for increasing SWB, whether administered in-person or online. Furthermore, development of the skills targeted in the program (e.g., gratitude, mindfulness) accounted for SWB improvements. This study provides initial evidence that ENHANCE can promote SWB and offers insights regarding the processes involved in these changes. To bolster these findings, we present additional data (n = 74) from a fourth assessment showing within-person maintenance of SWB gains over 6 months in the original treatment condition (n = 39) and a replication of the immediate ENHANCE treatment effects in the waitlist condition (n = 36). We discuss potential avenues for the utilization of ENHANCE in basic research and applied disseminations.