Table 1.
Sociodemographic and Clinical Characteristics of Bipolar Youth at Baseline, by Baseline Criterion A Group Assignment (N = 361)
| Characteristic | Irritable Only (n = 36) | Elated Only (n = 54) | Both (n = 271) | Group Contrast P Valuea |
|---|---|---|---|---|
| Sociodemographic characteristics
| ||||
| Age, mean ± SD, y | 10.5 ± 2.8b | 12.7 ± 3.4c | 12.7 ± 3.3c | .01d |
| Gender, male, % | 44.4 | 42.6 | 53.1 | .3e |
| Race, white, % | 88.9 | 72.2 | 79.7 | .2e |
| Ethnicity, Hispanic, % | 2.8 | 7.4 | 7.0 | .8e |
| Socioeconomic status, mean ± SDf | 3.1 ± 1.2 | 3.6 ± 1.2 | 3.3 ± 1.2 | .2d |
| Living with both natural parents, % | 41.7 | 37.0 | 41.3 | .8e |
|
| ||||
| Clinical characteristics
| ||||
| Pubertal status category, % | .03e | |||
| I | 37.9 | 19.0 | 28.5 | |
| II–III | 41.4 | 23.8 | 24.0 | |
| IV–V | 20.7 | 57.1c | 47.5c | |
| Bipolar type, % | .1e | |||
| Bipolar I | 44.4 | 57.4 | 66.1 | |
| Bipolar II | 8.3 | 5.6 | 5.2 | |
| Bipolar not otherwise specified | 47.2 | 37.0 | 28.8 | |
| Age at onset of mood symptoms, mean ± SD, y | 6.8 ± 3.4 | 8.3 ± 4.4 | 8.4 ± 4.2 | .2g |
| Age at onset of bipolar disorder, mean ± SD, y | 8.2 ± 3.3 | 9.6 ± 4.3 | 9.2 ± 4.0 | .3g |
| Duration of bipolar disorder, mean ± SD, y | 2.4 ± 1.7 | 3.1 ± 2.6 | 3.4 ± 2.7 | .05d |
a
Significant P values (< .05) are shown in bold type.
b
Group differs significantly from elated-only and both irritable and elated groups in pairwise contrasts.
c
Group differs significantly from irritable-only group in pairwise contrasts.
d
P value obtained from F test.
e
P value obtained from χ2 test.
f
See Hunt et al11 on measurement of socioeconomic status.
g
P value obtained from Kruskal-Wallis test.