Consecutive pairs of cohorts were assigned in a pairwise random fashion to receive either TAU or the 6-hr intervention in place of 6 hr of treatment that would have occurred at that same time (TAU + ACT; referred to as the ACT condition in the rest of the article). The design was similar to an additive treatment design, except that those in the ACT condition participated in 6 hr less of their regular program than those in TAU. TAU at this facility consisted of five or six therapy groups per day, 6 days per week. Seven were process groups, with the rest of the groups focusing on life skills, relapse prevention, parenting, physical health issues, recreational therapy, and anger management. The 2 hr of individual therapy per week often focused on 12-step facilitation. Therapy attendance was estimated by the clinical director to be over 90%, but actual attendance was not recorded. The residential program was designed to last 28 days (actual average length of attendance = 29.27 days, SD = 12.7, range = 2–74). A CONSORT chart is shown in Figure 1.
