1. Faculty of Pharmaceutical Sciences; University of Iceland; Reykjavík Iceland
2. Clinical Pharmacology; Institute of Public Health; University of Southern Denmark; Odense Denmark
3. Department of Clinical Chemistry & Pharmacology; Odense University Hospital; Odense Denmark
4. Centre of Development; Primary Health Care of the Capital Area; Reykjavik Iceland
5. Department of Psychiatry; Landspítali University Hospital; Reykjavik Iceland
6. Department of Clinical Pharmacy; Division Laboratory and Pharmacy; University Medical Center; Utrecht The Netherlands
7. Division of Pharmacoepidemio-logy and Clinical Pharmacology; Faculty of Science; Utrecht University; Utrecht The Netherlands