Volunteers aged between 18 and 60 years have been recruited through general practices, advertisements and a website (http://www.newmood.co.uk) from Greater Manchester, UK and Budapest, Hungary, under the aegis of the NewMood study (New Molecules in Mood Disorders, Sixth Framework Program of the European Union LHSM-CT-2004-503474). A questionnaire pack and a genetic sampling kit were sent to each participant who signed the official informed consent form provided by mail. From the total recruited 2588 participants we carried out our analysis in a group of 2234 subjects (896 from Budapest and 1338 from Manchester). We included only non-related individuals with European white ethnic origin who could be genotyped for the 5-HTTLPR polymorphism and provided eligible phenotypic data. More details about the population sample can be found in our previously published reports.36, 38, 39 This study was conducted in accordance with the Declaration of Helsinki, and has been approved by the local ethic committees (North Manchester Local Research Ethics Committee, Manchester, UK; Scientific and Research Ethics Committee of the Medical Research Council, Budapest, Hungary). All subjects gave written informed consent before participating in the study.
