Table 2.
Sample characteristics
| Service users (n = 42) |
Siblings (n = 17) |
Controls (n = 40) |
Test statistic | p | |
|---|---|---|---|---|---|
| Age (years), mean (SD) | 15.4 (1.4) | 15.3 (2.3) | 15.6 (2.0) | F = 0.24, df = 2 | 0.785 |
| Sex, n (%) | |||||
| Female | 25 (59.5) | 10 (58.8) | 23 (57.5) | χ2 = 0.04, df = 2 | 0.983 |
| Male | 17 (40.5) | 7 (41.2) | 17 (42.5) | ||
| Ethnicity, n (%)a | |||||
| White Dutch | 26 (61.9) | 11 (64.7) | 25 (64.1) | χ2 = 0.06, df = 2 | 0.970 |
| Other | 16 (38.1) | 6 (35.3) | 14 (35.9) | ||
| Level of education, n (%)c | |||||
| School | 30 (71.4) | 7 (41.2) | 17 (42.5) | χ2 = 10.48, df = 2 | 0.033 |
| Further | 12 (28.6) | 8 (47.1) | 20 (50.0) | ||
| Higher | – | 2 (11.8) | 3 (7.5) | ||
| Cannabis use, n (%) | |||||
| 12-months | 9 (21.4) | 1 (5.9) | 4 (10.0) | χ2 = 3.36, df = 2 | 0.187 |
| Lifetime | 9 (21.4) | 2 (11.8) | 5 (12.5) | χ2 = 1.50, df = 2 | 0.473 |
| Attempted suicide, n (%) | |||||
| During last year | 6 (14.6) | – | – | – | – |
| Before age 17 | 8 (19.1) | – | – | – | – |
| DSM-IV diagnoses, n (%) | |||||
| Pervasive developmental disorders NOS | 10 (23.8) | – | 5 (12.5) | – | – |
| Attention-deficit and disruptive behaviour | 6 (14.3) | 3 (17.6) | – | – | – |
| Adjustment disorders | 4 (9.5) | – | – | – | – |
| Anxiety disorders | 2 (4.8) | – | – | – | – |
| Depressive disorders | 2 (4.8) | – | – | – | – |
| Gender identity disorders | 2 (4.8) | – | – | – | – |
| Learning disorders | – | – | 2 (5.0) | – | – |
| Other disorders of infancy, childhood, or adolescence | 5 (11.9) | – | – | – | – |
| Parent–child relational problem | 5 (11.9) | 1 (5.9) | 1 (2.5) | – | – |
| Comorbid conditionb | 24 (57.1) | 2 (11.8) | – | – | – |
| None | 6 (14.3) | 13 (76.5) | 32 (80.0) | – | – |
| BDI-II sum sores, mean (SD)a,d,e | 12.8 (9.2) | 3.9 (3.3) | 6.9 (7.0) | F = 10.5, df = 2 | < 0.001 |
| CAPE sum scores, mean (SD)d,e | |||||
| Positive | 10.0 (9.4) | 3.9 (3.2) | 4.6 (3.9) | F = 8.28, df = 2 | < 0.001 |
| Negative | 9.9 (6.7) | 5.6 (3.8) | 7.4 (4.8) | F = 3.88, df = 2 | 0.024 |
| Depressive | 7.7 (4.0) | 4.2 (1.8) | 4.7 (3.4) | F = 9.90, df = 2 | < 0.001 |
| STAI-DY1 (state anxiety)a sum scores, mean (SD)d,e | 35.5 (10.6) | 30.2 (6.8) | 31.1 (7.2) | F = 3.47, df = 2 | 0.035 |
| STAI-DY2 (trait anxiety)a sum scores, mean (SD)d,e | 85.6 (20.8) | 67.1 (9.2) | 74.1 (16.4) | F = 8.12, df = 2 | < 0.001 |
| Number of valid beeps, mean (range, min–max) | 43.8 (24–59) | 42.8 (23–57) | 44.9 (25–58) | F = 0.23, df = 2 | 0.764 |
| Service users vs. controls | Siblings vs. controls | Service users vs. siblings | ||||
|---|---|---|---|---|---|---|
| β (95% CI) | p | β (95% CI) | p | β (95% CI) | p | |
| BDI-II | 0.71 (0.30–1.11) | 0.001 | − 0.37 (− 0.89–0.16) | 0.168 | 1.08 (0.55–1.60) | < 0.001 |
| CAPE | ||||||
| Positive | 0.75 (0.34–1.17) | < 0.001 | − 0.09 (− 0.63–0.44) | 0.735 | 0.84 (0.31–1.38) | 0.002 |
| Negative | 0.42 (− 0.01–0.85) | 0.057 | − 0.31 (− 0.87–0.25) | 0.269 | 0.73 (0.17–1.29) | 0.011 |
| Depressive | 0.80 (0.40–1.21) | < 0.001 | − 0.12 (− 0.64–0.41) | 0.666 | 0.92 (0.39–1.45) | 0.001 |
| STAI-DY1 | 0.50 (0.06–0.93) | 0.025 | − 0.09 (− 0.65–0.47) | 0.748 | 0.59 (0.03–1.14) | 0.040 |
| STAI-DY2 | 0.59 (0.19–0.99) | 0.004 | − 0.36 (− 0.88–0.16) | 0.170 | 0.95 (0.43–1.46) | < 0.001 |
SD standard deviation, df degrees of freedom, β standardized regression coefficients (mean score differences), vs. versus, CI confidence interval
aMissing values: ethnicity = 1, BDI = 1, STAI-DY1 = 1, STAI-DY2 = 2
bConsisting of the following diagnostic categories in the service users group: Additional codes (Parent–child relational problem, 33.3%; Borderline intellectual functioning, 13.3%; Neglect of child, 6.7%), Attention-deficit and disruptive behaviour disorders (10%), Learning disorders (10%), Personality disorders (6.7%), Mild mental retardation (6.7%), Anxiety disorders (3.3%), Dissociative disorders (3.3%), Tic disorders (3.3%), Amphetamine related disorders (3.3%)
cCategories defined as: school (primary education, LBO, MAVO, VMBO), further (MBO, HAVO, VWO), and higher (HBO, WO) education of the Dutch educational system
dCut-off scores of clinically significant severity: BDI-II = total score above 13; STAI-DY1 = score above 40
eStandardized mean score differences across groups