Table 2.

Descriptive information on past-month substance use before and at the end of 6-month intervals for the 11 most common relationship combinations

	Heavy drinking episodes		Times used marijuana		No. of cigarettes per daya
Variable	Time 1 M(SD)	Time 2 M(SD)	Time 1 M(SD)	Time 2 M(SD)	Time 1 M(SD)	Time 2 M(SD)
Single to
Single (n = 979)	1.68 (2.72)	1.68 (2.70)	2.33 (4.27)	2.38 (4.36)	2.61 (5.10)	2.70 (5.17)
Dating (n = 254)	2.54 (3.13)	2.32 (3.05)	2.89 (4.55)	2.48 (4.31)	3.22 (5.37)	3.71 (5.79)
Cohabiting (n = 46)	3.00 (3.14)	2.72 (3.51)	5.04 (5.77)	4.65 (5.63)	7.76 (7.22)	6.22 (6.85)
Dating to
Single (n = 222)	2.20 (2.97)	2.58 (3.13)	2.65 (4.13)	3.33 (4.65)	3.91 (5.80)	4.41 (5.98)
Dating (n = 505)	2.01 (2.82)	1.82 (2.66)	2.18 (4.13)	1.95 (3.93)	2.22 (4.65)	2.30 (4.77)
Cohabiting (n= 119)	1.28 (2.19)	1.72 (2.71)	2.78 (4.61)	2.64 (4.74)	3.73 (6.01)	3.93 (6.22)
Dating new partner (n = 48)	2.40 (2.82)	2.32 (2.90)	1.75 (3.52)	2.60 (4.18)	3.16 (5.36)	3.16 (5.36)
Cohabiting to
Single (n = 29)	1.24 (2.18)	2.90 (3.20)	4.52 (5.32)	5.59 (5.48)	6.92 (7.14)	6.69 (6.80)
Dating (n = 62)	2.00 (3.06)	1.22 (2.05)	2.89 (5.32)	3.02 (5.48)	6.93 (7.16)	6.83 (7.24)
Cohabiting (n= 188)	1.61 (2.66)	1.33 (2.32)	2.66 (4.45)	2.70 (4.63)	4.81 (6.60)	4.93 (6.62)
Married to
Married (n = 58)	0.84 (2.14)	0.97 (2.37)	0.34 (1.29)	0.26 (1.12)	2.62 (5.26)	1.78 (4.38)

Notes: Time 1 = prior to 6-month interval; Time 2 = end of 6-month interval.

^aData on smoking not available at the first interval for the older cohort in the sample. Thus, means for smoking are based on approximately 12% fewer person-intervals than means for other types of substance use.