Table 1 Demographic and baseline clinical characteristics of participants with bipolar depression (intent-to-treat population)

Bipolar I/II, n

15/16

19/12

Chi² = 1.042, df = 1, p = 0.307

Age, mean (SD), years

41.8 (12.8)

48.0 (14.2)

T = 1.8, df = 60, p = 0.07

Sex, male/female, n

14/17

16/15

Chi² = 0.258, df = 1, p = 0.611

Total no. of mood episodes, mean (SD)

8.0 (7.8)

9.5 (9.2)

Duration of illness (mean), years

12.3 (9.7)

18.1 (15.1)

T = 1.694, df = 52, p = 0.096

Mean HASF score (SD); n = 62

5.9 (2.0)

6.1 (2.4)

T = 0.351, df = 60, p = 0.727

Mean State-STAI score (SD); n = 61

58.2 (9.5)

57.4 (9.1)

T = − 0.347, df = 59, p = 0.727

Mean Trait-STAI score (SD); n = 61

58.4 (11.4)

57.9 (9.9)

T = 0.189, df = 59, p = 0.850

HAMD baseline score, mean (SD)

20.9 (3.0)

21.4 (4.3)

T = 0.549, df = 60, p = 0.585

MADRS baseline score, mean (SD)

28.8 (5.6)

30.3 (6.0)

T = 1.031, df = 60, p = 0.307