The psychotherapeutic treatment with CBASP will be conducted in 2 weekly sessions for the first 4 weeks, one per week thereafter until week 9, followed by one session every 2 weeks for 20 more weeks. The starting dose for Escitalopram will be 10 mg/d for one week and will be increased to 20 mg/d after one week. The dosage can be reduced to 10 mg/d after day 7 to improve tolerance. Th MADRS-scale is the primary outcome measure; ratings will be performed by a blinded rater. If there is no improvement (reduction of less than 20% of the MADRS), patients will be crossed over in terms of adding the other treatment at week 8. Study patients will be asked to participate in fMRI, genetic and pharmacological substudies.