The Depression Network (DeNT) Study: methodology and sociodemographic characteristics of the first 470 affected sibling pairs from a large multi-site linkage genetic study.
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 4th edition (DSM-IV) or the International Classification of Diseases 10th 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.
Farmer
Anne
A
Medical Research Council Social Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, London, UK. A.Farmer@iop.kcl.ac.uk
Breen
Gerome
G
Brewster
Shyama
S
Craddock
Nick
N
Gill
Mike
M
Korszun
Ania
A
Maier
Wolfgang
W
Middleton
Lefkos
L
Mors
Ole
O
Owen
Mike
M
Perry
Julia
J
Preisig
Martin
M
Rietschel
Marcella
M
Reich
Theodore
T
Jones
Lisa
L
Jones
Ian
I
McGuffin
Peter
P
D017668:Age of Onset; D003866:Depressive Disorder / Q000453:epidemiology / Q000235:genetics*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005060:Europe / Q000453:epidemiology; D005260:Female; D008040:Genetic Linkage; D020022:Genetic Predisposition to Disease / Q000453:epidemiology; D005820:Genetic Testing / Q000379:methods; D005838:Genotype; D006801:Humans; D038801:International Classification of Diseases; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D011569:Psychiatric Status Rating Scales; D012720:Severity of Illness Index; D035781:Siblings; D014481:United States / Q000453:epidemiology; D044465:White People / Q000706:statistics & numerical data