Table 1.
Sample Characteristics of 483 Participants Included From the September 2014 Data Release of the Human Connectome Projecta
| Cannabis, Mean (SD) |
||
|---|---|---|
| Characteristic | Unexposed (n = 221) |
Exposed (n = 262) |
| Age, y | 29.30 (3.46) | 29.32 (3.43) |
|
| ||
| Total household Incomeb | 5.24 (2.10) | 4.82 (2.21) |
|
| ||
| Age-adjusted picture vocabulary | 108.42 (14.57) | 106.35 (19.99) |
|
| ||
| NEO-FFI | ||
|
| ||
| Contentiousness | 34.92 (5.55) | 34.60 (5.66) |
|
| ||
| Extraversion | 30.18 (6.21) | 30.81 (6.22) |
|
| ||
| Neuroticism | 16.66 (7.32) | 16.26 (6.99) |
|
| ||
| Openness | 27.37 (5.78) | 28.42 (6.29) |
|
| ||
| Agreeablenessb | 32.59 (4.66) | 31.60 (4.72) |
|
| ||
| Delay discounting (AUC)c | 0.28 (0.22) | 0.21 (0.16) |
|
| ||
| ASR Impulsivityb | 1.14 (1.18) | 1.40 (1.30) |
|
| ||
| Female, %c | 69.68 | 52.29 |
|
| ||
| White,%c,d | 79.64 | 70.23 |
|
| ||
| Twins, % | 53.85 | 46.56 |
|
| ||
| Monozygotic twins, % | 50.42 | 43.44 |
|
| ||
| Lifetime depression history, % | 8.60 | 7.25 |
|
| ||
| Any childhood conduct problems,%b | 33.94 | 42.75 |
|
| ||
| Times ever used illicit drugs, %c | 2.71 | 34.35 |
|
| ||
| ≥2 Alcoholic drinks per day (heaviest), %c,e |
63.35 | 88.17 |
|
| ||
| Never smoked cigarettes (heaviest), %c,e | 90.95 | 57.63 |
|
| ||
| Cannabls use | ||
|
| ||
| Age at onset <17 y, % | NA | 48.85 |
|
| ||
| Lifetime quantity of use > 11 times, % | NA | 51.15 |
|
| ||
| Current abuse/dependence diagnosis, % |
NA | 17.56 |
|
| ||
| Use in the past 12 mo, % | NA | 36.26 |
Abbreviations: AUC, area under the curve; ASR, Achenbach Adult Self-Report; NA, not applicable; NEO-FFI, NEO Five-Factor Inventory.
Independent-samples t tests were used to compare means for the exposed and unexposed groups. χ2 Tests were used to compare ordinal/binary variables across groups. eAppendix 5 in the Supplement provides further details.
P < .05.
P < .001.
Race/ethnicity was coded as white, black or African American, or other race/ethnicity (including Asian, Pacific Islander, Native Hawaiian, multiracial, other, or not reported).
Alcoholic drinks per day and heaviness of cigarette smoking variables refer to use during the 12-month period of heaviest use.