Table 1. ABCD Study Sample Characteristicsa.
| Variable | No. (%) | |||
|---|---|---|---|---|
| Prenatal cannabis exposure after knowledge of pregnancy (n = 242) | Prenatal cannabis exposure before knowledge of pregnancy (n = 413) | No prenatal cannabis exposure (n = 10 834) | Total (N = 11 489) | |
| Child variables | ||||
| Age, mean (SD), y | 9.8 (0.6) | 9.9 (0.6) | 9.9 (0.6) | 9.9 (0.6) |
| Girls (n = 11 486) | 131 (54.1) | 194 (47.0) | 5164 (47.7) | 5489 (47.8) |
| Race/ethnicityb | ||||
| White | 144 (59.5) | 242 (58.6) | 8203 (75.7) | 8589 (74.8) |
| Black | 110 (45.4) | 172 (41.7) | 2094 (19.3) | 2376 (20.7) |
| Asian | 5 (2.1) | 13 (3.2) | 692 (6.4) | 710 (6.2) |
| Pacific Islander | 1 (0.4) | 5 (1.2) | 63 (0.6) | 69 (0.6) |
| Native American | 14 (5.8) | 17 (4.1) | 3.13 (3.2) | 374 (3.3) |
| Hispanic | 34 (14.1) | 89 (21.6) | 2215 (20.4) | 2338 (20.4) |
| Other | 8 (3.3) | 34 (8.2) | 722 (6.7) | 764 (6.7) |
| Child lifetime substance exposure | ||||
| Has tried alcohol (n = 11 482) | 52 (21.5) | 113 (27.4) | 2417 (22.3) | 2582 (22.5) |
| Has tried tobacco (n = 11 482) | 10 (4.1) | 12 (2.9) | 98 (0.9) | 120 (1.1) |
| Has tried marijuana (n = 11 482) | 3 (1.2) | 2 (0.5) | 9 (0.1) | 14 (0.1) |
| Pregnancy and family variables | ||||
| Unplanned pregnancy (n = 11 377) | 170 (70.3) | 111 (26.9) | 3865 (35.7) | 4336 (37.7) |
| Maternal age at birth, mean (SD), y (n = 11 336) | 25.3 (6.4) | 25.4 (5.9) | 29.7 (6.1) | 29.5 (6.2) |
| Prenatal vitamin use (n = 11 236) | 178 (73.6) | 392 (94.9) | 10 172 (93.9) | 10 742 (93.5) |
| Week learned pregnancy, mean (SD) (n = 10 375) | 8.3 (7.4) | 7.8 (6.5) | 6.9 (6.7) | 6.9 (6.8) |
| Maternal education, mean (SD), y (n = 10 974) | 13.7 (2.0) | 14.3 (2.2) | 15.3 (2.6) | 15.2 (2.6) |
| Household income (n = 10 507), $ | ||||
| ≤49 999 | 136 (56.2) | 204 (49.4) | 2764 (25.5) | 3104 (27.0) |
| 50 000-74 999 | 32 (13.2) | 54 (13.1) | 1368 (12.6) | 1454 (12.7) |
| 75 000-99 999 | 29 (12.0) | 37 (9.0) | 1445 (13.3) | 1511 (13.2) |
| 100 000-199 999 | 21 (8.7) | 60 (14.5) | 3136 (29.0) | 3217 (28.0) |
| ≥200 000 | 2 (0.8) | 21 (5.1) | 1198 (11.1) | 1221 (10.6) |
| Family history of psychopathologyc | ||||
| Psychosis (n = 11 205) | 15 (6.2) | 23 (5.6) | 223 (2.1) | 261 (2.3) |
| Depression (n = 11 329) | 139 (57.4) | 194 (47.0) | 3280 (30.3) | 3613 (31.5) |
| Anxiety (n = 11 150) | 58 (24.0) | 101 (24.5) | 1216 (11.2) | 1375 (12.0) |
| Antisocial behavior (n = 11 320) | 123 (50.8) | 151 (36.6) | 1146 (10.6) | 1421 (12.4) |
| Mania (n = 11 138) | 47 (19.4) | 46 (11.1) | 493 (4.6) | 586 (5.1) |
| Prenatal substance exposure before knowing of pregnancy | ||||
| Alcohol (n = 11 072) | 135 (55.8) | 255 (61.7) | 2391 (22.1) | 2781 (24.2) |
| Tobacco (n = 11 430) | 59 (65.7) | 230 (55.7) | 1117 (10.3) | 1506 (13.1) |
| Cannabis | 235 (97.1) | 413 (100) | 0 | 648 (5.6) |
| Prenatal substance exposure after knowing of pregnancy | ||||
| Alcohol (n = 11 446) | 63 (26.0) | 13 (3.2) | 214 (2.0) | 290 (2.5) |
| Tobacco (n = 11 458) | 114 (47.1) | 60 (14.5) | 392 (3.6) | 566 (4.9) |
| Cannabis | 242 (100) | 0 | 0 | 242 (2.1) |
| Child primary outcomes of interest, mean (SD) | ||||
| Psychotic-like experiences (n = 11 477) | 3.58 (4.0) | 3.17 (3.7) | 2.57 (3.5) | 2.61 (3.5) |
| Internalizing symptoms per CBCL (n = 11 483) | 7.83 (7.4) | 6.41 (6.1) | 4.88 (5.4) | 5.00 (5.5) |
| Externalizing symptoms per CBCL (n = 11 483) | 10.06 (9.2) | 6.44 (7.4) | 4.13 (5.5) | 4.34 (5.7) |
| Attention symptoms per CBCL (n = 11 483) | 5.53 (4.3) | 4.23 (4.0) | 2.80 (3.4) | 2.91 (3.4) |
| Thought symptoms per CBCL (n = 11 483) | 3.28 (3.4) | 2.24 (2.8) | 1.53 (2.1) | 1.59 (2.2) |
| Social symptoms per CBCL (n = 11 483) | 3.4 (3.2) | 2.3 (2.7) | 1.5 (2.2) | 1.6 (2.3) |
| Cognition composite (n = 11 249)d | 81.7 (8.6) | 84.6 (9.4) | 86.5 (9.1) | 86.3 (9.1) |
| Sleep problems per SDSC (n = 11 489) | 41.9 (13.5) | 38.9 (9.8) | 36.1 (8.1) | 36.4 (8.4) |
| BMI (n = 11 462) | 20.7 (5.9) | 19.7 (4.3) | 18.8 (4.2) | 18.8 (4.2) |
| Birth weight, oz (n = 11 113) | 108.8 (23.8) | 112.6 (22.6) | 112.3 (23.4) | 112.2 (23.4) |
| Gestational age at birth, wk (n = 11 414) | 39.3 (1.8) | 39.2 (2.1) | 39.1 (2.2) | 39.1 (2.9) |
| Total intracranial volume, mm3 (n = 11 024) | 9.9 (0.9) | 10.1 (0.9) | 10.2 (1.0) | 10.2 (1.0) |
| Total white matter volume, mm3 (n = 10 404) | 8.7 (1.0) | 8.9 (1.1) | 9.0 (1.0) | 9.0 (1.0) |
| Total gray matter volume, mm3 (n = 11 021) | 10.0 (0.9) | 10.2 (1.0) | 10.4 (1.0) | 10.4 (1.0) |
Abbreviations: ABCD, Adolescent Brain and Cognitive Development; BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); CBCL, Child Behavior Checklist; SDSC, Parent Sleep Disturbance Scale for Children.
Data included in analyses were required to have a response of yes or no for maternal report of using cannabis prior to and after knowledge of pregnancy. All variables reflect measures assessed during the baseline session when children were a mean (SD) age of 9.9 (0.6) years. In our analytic approach, all but 7 children who were exposed to cannabis prior to maternal knowledge of pregnancy were also coded as having prenatal exposure prior to maternal knowledge. The estimates reported above refer to the nonwinsorized versions of each variable (refer to the eMethods in the Supplement for descriptive information of the winsorized data). Brain metrics were scaled by dividing each value by the SD.
Race/ethnicity variables were coded as non–mutually exclusive dichotomous variables; as such, these numbers do not sum to 100% as participants could be included in multiple categories.
Family history of depression, psychosis, mania, antisocial behavior, and anxiety among first-degree relatives. Psychotic-like experiences were measured by the Prodromal Questionnaire–Brief Child Version total score.
Cognition composite was assessed using the National Institutes of Health Toolbox.