Objective: To describe a manual-based intervention to address clinical crises and retain participants in the Treatment for Adolescents with Depression Study (TADS). Method: The use of adjunct services for attrition prevention (ASAP) is described for adolescents (ages 12-17 years) during the 12-week acute treatment in TADS, from 2000 to 2003. Logistic regression, controlling for site, was used to predict use. Results: Of 439 enrolled participants, 17.8% (n = 78) used ASAP primarily for suicidality or worsening of depression. Of these, 46.2% continued in their assigned treatment through week 12, 47.4% received out-of-protocol treatment but continued participating in assessments, and 10.3% withdrew consent, including 3 who terminated treatment and withdrew consent on the same date. ASAP use did not differ between treatments (p = 0.97) and typically occurred early in treatment. At the end of the 12 weeks, 37.2% of participants using ASAP remained in their assigned treatment, although 80.8% continued participating in assessments. ASAP was associated with, at baseline, a higher severity of depression (p less than 0.01), substance use (p less than 0.01), and precontemplation level of change (p less than 0.02). Conclusions: ASAP may be useful to retain adolescent participants and as a safety intervention in placebo-controlled trials. In clinical practice ASAP-like procedures maybe useful to encourage adherence in patients engaging in long-term treatment. (Contains 4 tables.)