Table 1.
Participant characteristics for cannabis only (CAN), nicotine only (NIC), combined cannabis and nicotine groups (NIC+CAN), and non-using control group (CTRL).
| CAN Mean (SD) |
NIC Mean (SD) |
NIC+CAN Mean (SD) |
CTRL Mean (SD) |
F/t, p | |
|---|---|---|---|---|---|
| N | 53 | 28 | 26 | 30 | - |
| Demographic variables | |||||
| Age | 24.4 (7.9) | 32.7 (10.0) | 26.5 (8.0) | 28.8 (8.9) | F(3, 131) = 5.9, p = 0.001* |
| Males (N, %) | 38 (71.7) | 16 (57) | 19 (73.1) | 14 (46.7) | χ2(3) = 8.1; p = 0.043* |
| Years of Education | 13.3 (2.7) | 14.3 (2.4) | 13.3 (2.1) | 16.6 (1.7) | F(3, 131)= 12.7, p < 0.001* |
| IQ | 105.5 (13.0) | 111.2 (11.7) | 107.3 (12.2) | 111.6 (9.9) | F(3, 131) = 2.2, p = 0.09 |
| Substance use variables | |||||
| # cannabis use/last 90 days | 80.5 (15.2) | 1.43 (6.60) | 83.8 (12.0) | 0.0 | F(3, 131) = 576.2, p < 0.001* |
| Duration of regular cannabis use (years) | 6.5 (6.4) | n/a | 8.0 (7.6) | n/a | t(78) = −0.78, p = 0.44 |
| # cigarette smoking days/last 90 days | 7.3 (15.8) | 90 (0.0) | 89.5 (1.9) | 0.0 | F(3, 131) = 824.1, p < 0.001* |
| Pack yearsa | n/a | 8.6 (11.0) | 8.9 (14.8) | n/a | t(53) = −0.05, p = 0.96 |
| # drinking days/last 90 days | 23.1 (26.6) | 16.8 (22.9) | 21.0 (21.6) | 9.1 (19.5) | F(3, 131) = 2.31, p = 0.08 |
| Average drink per drinking day | 4.0 (2.9) | 3.3 (2.7) | 5.1 (3.2) | 1.5 (1.2) | F(3, 131) = 8.8, p < 0.001* |
| DSM-IV current alcohol abuse (N) | 9 | 2 | 5 | 1 | χ2(3) = 7.5; p = 0.28 |
| DSM-IV current alcohol dependence (N) | 6 | 1 | 2 | 0 | χ2(3) = 8.1; p = 0.043* |
| DSM-IV lifetime alcohol abuse (N) | 32 | 15 | 10 | 6 | χ2(3) = 20.4; p < 0.001* |
| DSM-IV lifetime alcohol dependence (N) | 24 | 10 | 5 | 3 | χ2 (3) = 8.0; p = 0.047* |
a
# cigarette packs per day/# years regular cigarette use