[1] Free Univ Berlin, Div Clin Psychol & Psychotherapy, Berlin, Germany
[2] Free Univ Berlin, Div Clin Psychol Intervent, Berlin, Germany
[3] Philips Univ Marburg, Dept Psychol, Marburg, Germany
[4] Philipps Univ Marburg, Dept Psychol, Clin Psychol & Psychotherapy, Marburg, Germany
[5] Univ Hosp Zurich, Inst Complementary & Integrat Med, Zurich, Switzerland
[6] Univ Med Ctr Hamburg Eppendorf, Dept Psychiat & Psychotherapy, Hamburg, Germany
[7] Ludwig Maximilians Univ Munchen, Dept Psychol, Munich, Germany
[8] Univ Zurich, Dept Psychol, Zurich, Switzerland
[9] Univ Zurich, Psychiat Univ Hosp Zurich, Dept Psychiat Psychotherapy & Psychosomat, Zurich, Switzerland