Table 1.
Socio-demographic and clinical characteristics of patients with BD, UR and HC at baseline, n=366
| BD | UR | HC | BD vs HC, p value | BD vs UR, p value | UR vs HC, p value | |
| Participants, n | 203 | 54 | 109 | |||
| Age, years | 28 (24–35) | 26 (22–31) | 26 (24–36) | 0.39 | 0.028 | 0.014 |
| Female sex, % (n) | 69.0 (140) | 56.6 (30) | 63.3 (69) | 0.31 | 0.064 | 0.34 |
| Education, years | 15 (13–17) | 15 (13–17) | 16 (15–17) | <0.001 | 0.27 | 0.09 |
| Full-time employment, % (n) | 32.0 (64) | 48.1 (25) | 50.0 (52) | 0.002 | 0.031 | 0.82 |
| Student, % (n) | 40.5 (81) | 46.2 (24) | 38.5 (40) | 0.73 | 0.46 | 0.36 |
| HAMD-17 | 9 (5–15) | 2 (0–3) | 0 (0–2) | <0.001 | <0.001 | 0.60 |
| YMRS | 2 (0–7) | 0 (0–2) | 0 (0–1) | <0.001 | <0.001 | 0.60 |
| FAST, total score | 22 (13–30) | 1 (0–3) | 0 (0–2) | <0.001 | <0.001 | 0.20 |
| BD type II, % (n) | 66.5 (135) | – | – | – | – | – |
| Age of onset, years | 17 (14–21) | – | – | – | – | – |
| Illness duration, years* | 10 (5–14) | – | – | – | – | – |
| Untreated BD, years† | 4 (1–10) | – | – | – | – | – |
| No. of prior depressive episodes | 5 (3–13) | – | – | – | – | – |
| No. of prior hypomanic episodes | 5 (2–15) | – | – | – | – | – |
| No. of prior manic episodes | 1 (1–2) | – | – | – | – | – |
| No. of prior mixed episodes | 1 (1–2) | – | – | – | – | – |
| No. of total episodes | 12 (6–27) | – | – | – | – | – |
| Episode at baseline‡ | ||||||
| Full or partial remission, % (n) | 60.6 (123) | – | – | – | – | – |
| Hypomania/mania, % (n) | 5.9 (12) | – | – | – | – | – |
| Depression, % (n) | 33.0 (67) | – | – | – | – | – |
| Mixed, % (n) | 0.5 (1) | – | – | – | – | – |
| Prescribed medication at baseline | ||||||
| Lithium, % (n) | 33.0 (67) | – | – | – | – | – |
| Antiepileptic treatment, % (n) | 49.8 (101) | – | – | – | – | – |
| Antipsychotic treatment, % (n) | 38.9 (79) | – | – | – | – | – |
| Antidepressant treatment, % (n) | 27.1 (55) | – | – | – | – | – |
| Other§, % (n) | 7.9 (16) | – | – | – | – | – |
| No psychotropic medicine, % (n) | 17.7 (36) | – | – | – | – | – |
Continuous variables are presented as mean (SD) or median (IQR) and p values are calculated based on differences in mean between the three groups using mixed models. Categorical data are presented as % (n) and p values are calculated by using the χ2 test.
*Illness duration was defined as the time from the first episode to the time of inclusion.
†Untreated BD was defined as time from the first mania, hypomania or mixed episode to time of diagnosis.
‡Episode at baseline according to HAMD-17 and YMRS, full or partial remission was defined as HAMD-17 and YMRS <14, scores on HAMD-17 or YMRS ≥14 were defined as depression or hypomania/mania and as mixed if both HAMD-17 and YMRS ≥14.
§Other includes benzodiazepines and melatonin.
BD, bipolar disorder; FAST, Functional Assessment Short Test; HAMD-17, Hamilton Depression Rating Scale 17-item; HC, healthy control individuals; UR, unaffected first-degree relatives; YMRS, Young Mania Rating Scale.