Demographic and clinical characteristics of participants
| Characteristic | No. (%) of participants* | t or χ2 | p value | |
|---|---|---|---|---|
| Healthy controls n = 49 | Bipolar disorder n = 46 | |||
| Demographics | ||||
| Age, yr, mean ± SD | 16.30 ± 1.75 | 17.30 ± 1.23 | −3.24 | 0.002 |
| Sex, female | 24 (49.0) | 25 (54.3) | 0.10 | 0.75 |
| Non-White | 22 (44.9) | 14 (30.4) | 1.88 | 0.17 |
| BMI, mean ± SD | 20.98 ± 2.81 | 23.81 ± 3.71 | −4.21 | < 0.001 |
| Intact family | 32 (65.3) | 28 (60.9) | 0.055 | 0.81 |
| Socioeconomic status, HI score, mean ± SD | 4.35 ± 0.86 | 4.17 ± 0.90 | 0.56 | 0.45 |
| Tanner stage, mean ± SD | 4.16 ± 0.59 | 4.33 ± 0.67 | 3.00 | 0.08 |
| CGAS: Most severe past episode, mean ± SD | 79.0 ± 7.9 | 41.9 ± 8.3 | 7.52 | < 0.001 |
| CGAS: Highest past year, mean ± SD | 90.4 ± 5.1 | 67.5 ± 11.7 | 12.1 | < 0.001 |
| CGAS: Past month, mean ± SD | 90.7 ± 4.3 | 64.0 ± 12.1 | 14.0 | < 0.001 |
| Lifetime clinical characteristics | ||||
| BD-I | 0 | 15 (32.6) | — | — |
| BD-II | 0 | 15 (32.6) | — | — |
| BD-NOS | 0 | 16 (34.8) | — | — |
| Age of BD onset, yr, mean ± SD | 0 | 14.7 ± 2.15 | — | — |
| Psychosis | 0 | 16 (34.8) | — | — |
| Suicide attempts | 0 | 7 (15.2) | — | — |
| Self-injurious behaviour | 0 | 23 (50.0) | — | — |
| Suicidal ideation | 3 (12.5) | 29 (63.0) | — | — |
| Physical or sexual abuse | 1 (2.0) | 2 (7.2) | — | — |
| Psychiatric hospital admission | 0 | 25 (54.3) | — | — |
| Current depression score, mean ± SD | 0.41 ± 1.47 | 14.15 ± 11.18 | — | — |
| Lifetime depression score, mean ± SD | 1.20 ± 2.56 | 29.93 ± 12.56 | — | — |
| Current mania score, mean ± SD | 0.08 ± 0.34 | 9.26 ± 10.12 | — | — |
| Lifetime mania score, mean ± SD | 0.63 ± 1.83 | 30.57 ± 10.97 | — | — |
| Lifetime comorbid diagnoses | ||||
| Attention-deficit/hyperactivity disorder | 6 (12.2) | 22 (47.8) | — | — |
| Oppositional defiant disorder | 0 | 11 (23.9) | — | — |
| Conduct disorder | 0 | 2 (4.3) | — | — |
| Any anxiety disorder | 1 (2.0) | 35 (76.1) | — | — |
| No. of anxiety disorders, mean ± SD | 0.04 ± 0.29 | 1.57 ± 1.42 | — | — |
| Substance use disorder | 0 | 12 (26.1) | — | — |
| Eating disorder | 0 | 10 (21.7) | — | — |
| Nicotine use | 3 (6.1) | 20 (43.5) | — | — |
| Family psychiatric history | ||||
| Mania or hypomania | 0 | 24 (55.8) | — | — |
| Depression | 8 (16.3) | 31 (72.1) | — | — |
| Suicide attempt | 5 (10.2) | 16 (37.2) | — | — |
| Anxiety | 7 (14.3) | 27 (62.8) | — | — |
| Psychosis | 0 | 11 (25.6) | — | — |
| Substance use disorder | 4 (8.2) | 21 (45.7) | — | — |
| Attention-deficit/hyperactivity disorder | 3 (6.1) | 10 (23.3) | — | — |
| Lifetime medications | ||||
| Second-generation antipsychotics | 0 | 34 (73.9) | — | — |
| Lithium | 0 | 12 (26.1) | — | — |
| SSRI antidepressants | 0 | 16 (34.8) | — | — |
| Non-SSRI antidepressants | 0 | 7 (15.2) | — | — |
| Stimulants | 4 (8.2) | 9 (19.6) | — | — |
| Lamotrigine | 0 | 10 (21.7) | — | — |
| Valproate | 0 | 2 (4.3) | — | — |
| Current medications | ||||
| Second-generation antipsychotics | 0 | 30 (65.2) | — | — |
| Lithium | 0 | 10 (21.7) | — | — |
| SSRI antidepressants | 0 | 4 (8.7) | — | — |
| Non-SSRI antidepressants | 0 | 3 (6.5) | — | — |
| Stimulants | 3 (6.1) | 2 (4.3) | — | — |
| Lamotrigine | 0 | 10 (21.7) | — | — |
| Valproate | 0 | 0 | — | — |
| Any current medication | 3 (6.1) | 39 (84.8) | — | — |
BD-I = bipolar disorder subtype I; BD-II = bipolar disorder subtype II; BD-NOS = bipolar disorder not otherwise specified; BMI = body mass index; CGAS = Children’s Global Assessment Scale; HI = Hollingshead Index; SD = standard deviation; SSRI = selective serotonin reuptake inhibitor.