Participants were 133 adults (61 female, 72 male; mean age = 33.6 years) diagnosed with a substance use disorder participating in a 28-day residential treatment program in Reno, Nevada. Fourteen percent of the participants identified themselves as non-Caucasians—African American (n = 6), American Indian (n = 3), Asian/Pacific Islander (n = 1), other (n = 7)—and 13% (n = 17) as Hispanic. The most common substances used in the 30 days prior to program entry were alcohol, methamphetamine, and marijuana (see Table 1). There was no significant difference between conditions on the number of substances used (mean treatment as usual [TAU] = 2.3, mean ACT = 1.9, Mann–Whitney U = 1,393, p = .18). The number of substances used or whether particular substances were used before program entry did not relate significantly to substance use outcomes during follow-up and did not affect the treatment outcomes reported here. All participants qualified for a diagnosis of substance abuse or dependence as a prerequisite for admittance to treatment.
