Table 1.

Demographic characteristics and COMT genotype frequency by treatment condition

Active (n = 363)Placebo (n = 361)
Age (y), M ± SD42 ± 1043 ± 10
Sex (male), n (%)152 (42)144 (40)
Socioeconomic status, n (%)
    I–professional11 (3)8 (2)
    II–managerial112 (31)117 (33)
    IIIa–nonmanual86 (24)75 (21)
    IIIb–manual75 (21)77 (21)
    IV–semiskilled63 (17)58 (16)
    V–unskilled16 (4)26 (7)
Nicotine dependence, M ± SD15 ± 515 ± 4
COMT genotype, n (%)
    Met/Met114 (31)109 (30)
    Met/Val165 (46)166 (46)
    Val/Val84 (23)86 (24)
  • NOTE: Baseline measures do not differ significantly between the active and placebo groups (P > 0.28).