Table 2.
Mean (standard deviation) usage characteristics of the Marijuana, Marijuana + Nicotine (MJ + NIC), Nicotine, and Control groups. Usage characteristics of nicotine and marijuana were not measured for the Overeaters group. Recent marijuana usage characteristics were not measured for the Nicotine or Control groups.
| Marijuana | MJ + NIC | Nicotine | Control | |
|---|---|---|---|---|
| Recent number of cigarettes per day* | 0.43 (1.57) | 10.17 (6.25)1 | 14.60 (7.60)1 | 0.11 (0.42)7 |
| Recent marijuana use per using day** | 3.33 (2.88)2 | 3.23 (1.69)2 | — | — |
| Marijuana use in last 90 days*** | 79.98 (17.04)3,4 | 81.32 (17.75)3,4 | 25.39 (35.80)3 | 0.27 (1.19)8 |
| Cigarette use in last 90 days*** | 5.99 (17.66)5 | 82.06 (19.45)5,6 | 89.95 (00.44)5,6 | 0.35 (1.40)9 |
Number of self-reported cigarettes on a typical using day from the Smoking History Questionnaire;
computed from questions about daily and weekly self-report estimates of number of times smoking marijuana from the Marijuana Use Questionnaire;
from Timeline Follow Back Calendar of the past 90 days.
Marijuana + Nicotine group reported smoking fewer cigarettes per day than the Nicotine group [t(142.3) = −3.85, p = 0.0002)],
but not fewer cannabis occasions per day than the Marijuana group [t(125.7) = −0.259, p = 0.80)].
The Marijuana and Marijuana + Nicotine groups used marijuana on more days than the Nicotine group [t(116.65) = 12.45, p<0.0001, t(121.94) = 12.43, p<0.0001 (respectively)],
but not less than one another [t(136.88) = 0.47, p = 0.64)].
The Nicotine and Marijuana + Nicotine groups smoked cigarettes on more days than the Marijuana group [t(86.11) = 44.33, p < 0.0001, t(125.82) = 24.57, p<0.0001 (respectively)],
with a slight difference between one another (t(62.05) = 3.22, p = 0.002).
Only two Control participants estimated any recent nicotine product use.
Both had only two occurrences. Only three Control participants estimated any nicotine product use in the past 90 days, only one of these individuals overlapped.
and only three Control participants estimated any marijuana use in the past 90 days: only one of these individuals overlapped. In total, 32 of the 37 Control participants reported no usage of nicotine or marijuana.