Statistical Analysis. In order to handle the hierarchical data structures (sessions at Level 1 nested within patients at Level 2 and therapists at Level 3), hierarchical linear model (HLM) with time as a within-groups factor and treatment condition as a between-groups factor will be used for the main research questions. The analyses will be conducted on the intention-to-treat sample as well as on the completer sample. To investigate if possible patients' and therapists' effects have an impact to the therapy outcomes, patients' and therapists' pretreatment characteristics are investigated as outcome predictors at Level 2 and 3. Clinical significance will be defined as (a) a statistically reliable change according to the Reliable Change Index (RCI), and (b) being within two standard deviations of a nonclinical group at post-assessment or follow-up (Jacobson & Truax, 1991). All the analyses will be run by HLM and R packet.