1. ACT inpatient treatment concept for OCD patients K. Albrecht 1, K. Wetterkamp 1, M. Stecher-Sperlich 1, L. Bonk 1, T. Freyer 1 1 University Medical Center Freiburg, Email: karoline.albrecht@uniklinik-freiburg.de Background Cognitive-behavioral therapy (CBT) with exposure and response prevention (ERP) as its key element is the psychotherapeutic method of choice in the treatment of obsessive-compulsive disorder (OCD). However, an essential number of patients - between 20 – 60% - do not benefit from treatment, fail to engage in the strenuous ERP treatment or drop out prematurely (Franklin & Foa, 1998; Abramowitz, 2006). Several factors - such as poor patient adherence to the ERP procedures or poor insight into the irrationality of the obsessions - have been reported to negatively impact the outcome of ERP (APA, 2007). ACT as an experiential contextual approach of cognitive behavioral therapy, which aims at changing the function of cognitions and other inner experiences rather than changing the content, might be a viable option to address the factors mentioned above (Twohig et al., 2010; Twohig, Hayes & Masuda, 2006; Tolin 2009). Its broad, not disorder-tailored nature might hold the chance to adequately deal with comorbidities and its procedures show promise in increasing treatment engagement in exposure treatments (Bluett et al., 2014). ACT in OCD treatment focuses on helping the patient to pursue valued-based living while mindfully noticing inner experiences, thus disempowering irrational or delusional obsessions and compulsive urges by not giving them more significance than they merit. So far studies suggest that ACT as an outpatient treatment seems to be a promising treatment approach for OCD (Twohig et. al., 2010; Twohig et al., in press). However no evidence exists on ACT for severe, chronic and treatment-refractory OCD in the inpatient setting.  The entire treatment team was trained in ACT with ongoing interdisciplinary training during the pilot phase.  Pilot study started 20 th April 2015: Interdisciplinary treatment concept with linked modules is feasible in clinical routine practice with positive patient feedback. Ongoing formative evaluation process.  Treatment study: start 01/01/2016 (evaluation of treatment response, quality of life, predictor- and moderator analysis). Feasibility and Outlook ACT for OCD 10-week inpatient treatment conceptTreatment modules ACT individual psychotherapy: * two sessions of 50 min/week  Introduction phase (Sessions 1 – 6):  assessment of symptomatology, creative hopelessness, treatment rationale and introduction to ACT, values clarification, commitment to ACT-based ERP.  Working phase (Sessions 7 – 14):  ACT-based ERP (in-session and alone), committed action, defusion and self as context exercises.  Final phase (Sessions 15 – 18):  transfer into home environment, arrangement of outpatient treatment continuation and of vocational integration. ACT values group: * two group psychotherapy sessions of 75 min/week; 6-10 patients  Matrix work: “value of the week” and respective meaningful commitment for the week.  Experiential group exercises (e.g. passengers on the bus, taking your mind for a walk). Fit for ERP group: * one session of 75 min/week; 4 sessions  Introduction into ACT-based ERP: difference between obsessions and compulsions, “control is the problem, not the solution!”, ERP rationale under ACT perspective, two scales metaphor. Mindfulness group: * one session of 90 min/week; 8 sessions  Mindfulness exercises (e.g. mindfulness of breath, bodyscan, sitting meditation, mindfull walking). ACT body mindfulness group: * one session of 50 min/week  Physiotherapeutic work with the six core ACT processes. ACT art group therapy: * two sessions of 90 min/week  Art therapeutic work with the six core ACT processes.