Research article

The Depression Network (DeNT) Study: methodology and sociodemographic characteristics of the first 470 affected sibling pairs from a large multi-site linkage genetic study

Anne Farmer¹ , Gerome Breen¹ , Shyama Brewster² , Nick Craddock³ , Mike Gill⁴ , Ania Korszun⁵ , Wolfgang Maier⁶ , Lefkos Middleton² , Ole Mors⁷ , Mike Owen³ , Julia Perry² , Martin Preisig⁸ , Marcella Rietschel⁹ , Theodore Reich^{10^} , Lisa Jones³ , Ian Jones³ and Peter McGuffin¹

¹  Medical Research Council Social Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, London, UK

²  Glaxo Wellcome Research and Development, Greenford UK

³  Dept of Psychological Medicine, University of Wales, College of Medicine, Cardiff UK

⁴  Department of Psychiatry, Trinity Centre for Health Sciences, Dublin Eire

⁵  Barts and The London, Queen Mary's School of Medicine and Dentistry, London UK

⁶  Department of Psychiatry, University of Bonn, Bonn, Germany

⁷  Department of Psychiatry, University of Aarhus, Aarhus, Denmark

⁸  University of Lausanne, Faculty of Biology and Medicine, Hopital de Cery, Unite psychopathologie, Prilly, Switzerland

⁹  Zentralinstitut for mental health, Mannheim, Germany

¹⁰  Dept of Psychiatry, Washington University, St Louis, USA

author email corresponding author email^Deceased

BMC Psychiatry 2004, 4:42doi:10.1186/1471-244X-4-42

Published:	9 December 2004

Please note that Dr Reich died after the completion of this study.

Abstract

Background

The Depression Network Study (DeNt) is a multicentre study designed to identify genes and/or loci linked to and/or associated with susceptibility to unipolar depression in Caucasian families. This study presents the method and socio-demographic details of the first 470 affected sibling pairs recruited from 8 different sites in Europe and the United States of America.

Methods

Probands fulfilling either the Diagnostic and Statistical Manual 4^th edition (DSM-IV) or the International Classification of Diseases 10^th edition (ICD-10) criteria for recurrent unipolar depression of moderate or severe degree and who had at least one similarly affected sibling were eligible for the study. Detailed clinical and psychological assessments were undertaken on all subjects including an interview using the Schedules for Clinical Assessment in Neuropsychiatry. Blood samples were collected from all participants to extract DNA for linkage analysis.

Results

The different sites used different recruitment strategies depending on local health care organisation but despite this there was remarkable similarity across sites for the subjects recruited. Although the Bonn site had significantly older subjects both for age of onset and age at interview, for the sample as a whole, subjects were interviewed in their mid-40s and had experienced the onset of their recurrent depression in their 20s. Preliminary genome screening was able to include 929 out of the 944 subjects (98.4%) typed at 932 autosomal and 544 X chromosome markers

Conclusions

This paper describes the methodology and the characteristics of the subjects from the 414 families included in the first wave of genotyping from the multi-site DeNT study. Ultimately the study aims to collect affected sibling pairs from approximately 1200 families.