Participant characteristics of the entire NorComt study population at treatment and study entry have been reported on previously [
18,
19]. Briefly, 531 of 548 provided valid QOL10 scores (described in “Quality of life instrument” below) and were included in this analysis. The sample was comprised of 28.2% women (
n = 150), with an average age of 33.4 (
SD 9.8). Half had a substance-using social network (51.4%,
n = 272) while 16.9% had no network (
n = 90), and 55.9% (
n = 297) reported over the cut-off for clinically concerning mental distress on the Hopkins Symptoms Checklist-25. Forty-four percent reported eating most of their meals alone (
n = 235), while 53.1% ate with friends, family, or others (
n = 282). Half were entering into outpatient opioid maintenance treatment (50.1%,
n = 266), and half into residential treatment for opioid or other substances (49.9%,
n = 265). Nearly all were polysubstance users (91.5%,
n = 485), with the most commonly used substance in the past six months for a plurality being heroin (23.7%,
n = 126), followed by amphetamines (19.8%,
n = 105), cannabis (16.9%,
n = 90), and alcohol (7.9%,
n = 42).