The current study investigated the relationship between social support and quality of life (QoL) as well as social support and community functioning among persons with severe and persistent mental illness (SPMI). Empirical data from Phase II of the Continuity of Mental Health Services (COMHS) Study of Alberta (Adair, Wild, Joyce, McDougall, Gordon, et al., 2003) were used to comprehensively examine these variables among a broad-based sample of 301 people with SPMI receiving a mix of inpatient, outpatient, and community services. Multiple measures administered in Phase II of the COMHS research program provided comprehensive data on QoL (i.e., disease-specific and generic QoL), functioning (i.e., community ability), and objective (OSS) and subjective (SSS) measures of social support. Higher ratings of both OSS and SSS were associated with better QoL and functioning at outcome. Participant ratings of objective dimensions of their own social support were shown to be most important in determining life quality and functioning at outcome. Of the two SSS variables, the one most predictive of life quality was the participants’ sense of the provision and receipt of social support. Clinician-rated OSS was a significant predictor of QoL only for participants who rated social support availability as poor. The results of this study may inform policy development, planning, and resource allocation for community treatment programs in Alberta and elsewhere, as there is widespread support both provincially and nationally for increasing community support services and decreasing the number and length of inpatient admissions (Kirby & Keon, 2006). A better understanding of the relative impact of social support variables is essential for further development of effective psychosocial rehabilitation programming. / xvii, 217 leaves ; 29 cm.