1 Department of Psychology, Psychotherapeutic University Outpatient Clinic for Behavior Therapy, University of Hamburg, Hamburg D-20146, Germany National Center for Complementary and Alternative Medicine (NCCAM), National Institute of Mental Health (NIMH) and Clinical Center, Department of Bioethics, National Institutes of Health (NIH), Bethesda, MD, USA Department of Neurology, University Hospital Essen, University Duisburg-Essen, Essen, Germany Department of Cognitive and Clinical Neuroscience, Central Institute of Mental Health/Medical Faculty Mannheim, Heidelberg University, J5, D-68159 Mannheim, Germany.