Percent relatives affected
Investigators
Year
N
Proband’s
primary drug
dependence
Father
Mother
or
mother
Brother
Sister
or sister
First
degree
Drug abusers
Polischa
1933
66
Opiate
2
5
3b
4
4b
Smith et al.a
1966
100
14
Vaillanta
1
24c
Ellinwood et al.a
111
3
0
2c
9c
O’Donnella
1969
266
3c
5c
Hawks et al.
74
Amphetamines
4c
16
Willisa
50
6c
8c
1971
8
Hill et al.
1977
114
1c
18
12
Maddux et al.a
1989
235
0b
20b
12b
8b
Mirin et al.
1991
350
Mixed
9
Rounsaville
201
37
20
Luthar et al.
1992
1993
298
Cocaine
6
40
22
33c
Controls
Male
Female
Either
ECA Sample
9339
7
360d
published 2000