TABLE 2.
Demographic information (i.e., age, sex, race, and education), measures of cannabis use, and tobacco usage, for the included AUD (n = 78) and matching CON (n = 78) participants
| Parameter | AUD (n = 78) | CON (n = 78) | Statistical results |
|---|---|---|---|
| Demographics | |||
| Age (years) m, SD | 29.0 ± 3.5 | 28.8 ± 3.7 | t = 0.35, df = 154, p = 0.73 |
| (22 to 36) | (22 to 35) | ||
| Sex | 35 F, 43 M | 41 F, 37 M | X2(1,202) = 0.92, p = 0.34 |
| Race | 67 White, 4 AA, 7 other | 62 White, 10 AA, 6 other | X2(2,156) = 2.84, p = 0.24 |
| Education (years) | 15.6 ± 1.4 | 15.5 ± 1.4 | t = 0.45, df = 154, p = 0.66 |
| m, SD (range) | (11 to 17) | (12 to 17) | |
| Cannabis use | |||
| Lifetime cannabis dependence? | 0 | 0 | X2(1,156) = 0, p = 1 |
| Tobacco usage | |||
| Last 7 Days tobacco use | 2.76 ± 10.17 | 2.92 ± 10.02 | t = 0.10, df = 154, p = 0.92 |
| (0 to 60) | (0 to 56) | ||
| Smoking history | Never (n = 31) | Never (n = 32) | X2(3,202) = 0.50, p = 0.92 |
| 1 to 19 times (n = 13) | 1 to 19 times (n = 10) | ||
| 20 to 99 times (n = 13) | 20 to 99 times (n = 13) | ||
| regular smoker (n = 21) | regular smoker (n = 23) | ||
| Still smoking? | 10 Yes, 68 No | 11 Yes, 67 No | X2(1,156) = 0.06, p = 0.81 |
| Fagerstrom FTND score | 0 (n = 66) | 0 (n = 70) | X2(3,202) = 1.55, p = 0.67 |
| 1 (n = 4) | 1 (n = 3) | ||
| 2 (n = 5) | 2 (n = 2) | ||
| 3 (n = 3) | 3 (n = 3) | ||
| Delay discounting | |||
| AUC for discounting of $200 (range) | 0.248 ± 0.159 (0.032 to 0.694) | 0.278 ± 0.220 (0.038 to 0.984) | t = 0.976, df = 154, p = 0.331 |
| AUC for discounting of $40,000 (range) | 0.507 ± 0.252 (0.046 to 0.977) | 0.567 ± 0.290 (0.047 to 0.969) | t = 1.379, df = 154, p = 0.170 |
| Averaged AUC for discounting of $200 and $40,000 (range) | 0.377 ± 0.189 (0.049 to 0.797) | 0.423 ± 0.233 (0.050 to 0.965) | t = 1.354, df = 154, p = 0.178 |
| NEO Personality inventory (NEO-PI) | |||
| NEO-Neuroticism | 17.22 ± 8.34 (1 to 39) | 16.91 ± 8.22 (1 to 38) | t = 0.234, df = 154, p = 0.815 |
| Alcohol usage | |||
| Total drinks in past 7 days (range) | 8.19 ± 6.60 (0 to 47) | 3.79 ± 4.72 (0 to 21) | t = 4.779, df = 153, p<.0001 |
| Drinks per drinking day in past 12 months (range) | 3.00 ± 0.96 (0 to 6) | 1.99 ± 2.31 (0 to 6) | t = 3.546, df = 153, p = 0.0005 |
| Frequency of any alcohol use in past 12 months (range; smaller number represents larger frequency) | 3.28 ± 2.95 (1 to 6) | 4.63 ± 1.50 (1 to 6) | t = 3.598, df = 153, p = 0.0004 |
| Drinks per day in heaviest 12-month period (range) | 4.51 ± 1.29 (1 to 6) | 3.31 ± 1.73 (1 to 6) | t = 4.891, df = 153, p<.0001 |
| Frequency of any alcohol use, heaviest 12-month period (range; smaller number represents larger frequency) | 1.74 ± 0.96 (1 to 5) | 3.82 ± 1.83 (1 to 6) | t = 8.844, df = 153, p<.0001 |
| Averaged Z score for SSAGA measures of alcohol use (range) | 0.400 ± 0.597 (−1.011 to 2.273) | −0.401 ± 0.592 (−1.460 to 1.070) | t = 8.387, df = 153, p<.0001 |
| Head motion during the fMRI scan | |||
| Mean frame-wise displacement (mm) | 0.158 ± 0.051 (0.088 to 0.397) | 0.157 ± 0.049 (0.079 to 0.343) | t = 0.125, df = 154, p = 0.901 |
| Proportions of larger reward or larger punishment | |||
| Proportion of larger reward | Median: 0.495 | Median: 0.5 | X2 (1,155) = 0.05, p = 0.8299 |
| IQR: 0.125 | IQR: 0.125 | ||
| Proportion of larger punishment | Median: 0.5 | Median: 0.5 | X2 (1,155) = 0.17, p = 0.6816 |
| IQR: 0.188 | IQR: 0.171 | ||
| Reaction time during the task | |||
| RT during larger reward (ms) | Median: 382 | Median: 372 | X2 (1,140) = 0.18, p = 0.6724 |
| IQR: 146 | IQR: 161 | ||
| RT during smaller reward (ms) | Median: 385 | Median: 375 | X2 (1,143) = 0.01, p = 0.9824 |
| IQR: 152 | IQR: 170 | ||
| RT during larger punishment (ms) | Median: 364 | Median: 368 | X2 (1,145) = 0.01, p = 0.961 |
| IQR: 139 | IQR: 153 | ||
| RT during smaller punishment (ms) | Median: 366 | Median: 368 | X2 (1,145) = 0.1, p = 0.7464 |
| IQR: 131 | IQR: 152 | ||
Student t and chi-square tests were used to test the group difference in continuous and category variables, respectively. Delay discounting, head motion during MRI scan, proportions of larger reward or larger punishment during the task, and RTs during the task, for the included AUD (n = 78) and match CON (n = 78) participants. Variables with normal distribution are shown using mean ±standard deviation, and variables with nonnormal distribution are shown using median and interquartile range (IQR). For these two kinds of variable, group differences were tested using Student t and Kruskal-Wallis tests, respectively. There were some NaN (i.e., not a number) in the alcohol usage and RT; therefore, the total degree of freedom was smaller than 155 when this happened. AUC, area under curve; AUD, alcohol use disorder; CON, control; m, mean; SD, standard deviation.