1. Health, Medical and Neuropsychology Unit, Leiden University, P.O. Box 9500, 2300 RA Leiden, The Netherlands
2. Leiden Institute for Brain and Cognition, Leiden University, P.O. Box 9500, 2300 RA Leiden, The Netherlands
3. The Center for Interdisciplinary Placebo Studies Leiden, P.O. Box 9500, 2300 RA Leiden, The Netherlands
4. Department of Rheumatology, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden, The Netherlands
5. Methodology and Statistics Unit, Leiden University, P.O. Box 9500, 2300 RA Leiden, The Netherlands
6. Department of Psychiatry, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden, The Netherlands
7. Medical Delta (Collaboration of Leiden University, Technical University Delft and Erasmus University), 2629 JH Delft, The Netherlands