a
face-to-face
interview.
Table 1
Composition and distribution of multilocus genetic profile (MLGP) scores.
Polymorphism Genotypes N DA profile scores
DRD2 Taq1A A1+ 89 Low
A1 − 127 High
DRD2-141C Ins/Del Del+ 66 High
Ins/Ins 150 Low
DAT1 VNTR 9-repeat 95 High
10/10 116 Low
COMT Val158Met Met/Met 36 High
Val/Met 102 Intermediate
Val/Val 72 Low
C957T C − 48 High
C+ 168 Low
rs12364283 T+ 35 High
T − 181 Low
Individual MLGP scores represent the sum of the value assigned to each DA genotype across
the six functional polymorphic loci included in this study. ‘High’ genotypes received a score of
1; ‘intermediate’ a score of 0.5; and ‘low’ genotypes a score of 0. For example, an individual
with the following polymorphisms: A1+ (Taq1A), Del+ ( − 141C Ins/Del), 9-repeat (DAT1
VNTR), Met/Met (COMT Val158Met), C − (C957T), and T+ (rs12364282) would have a
MLGP score of 5 (0 + 1 + 1 + 1 + 1 + 1).
2308 C. Davis, N.J. Loxton / Addictive Behaviors 38 (2013) 2306–2312
Height and weight were measured with the participant standing in
stocking feet and wearing light indoor clothing, and the blood sample
was taken at the hospital laboratory. After the questionnaire package
was completed, the participant was paid a small stipend to cover
out-of-pocket expenses.