Table 2.

Mean (SD) scores for participants in the bipolar and unipolar groups on clinical measurements, and between-group comparisons

	Bipolar (n = 20) Mean (SD)		Unipolar (n = 20) Mean (SD)		t	p-value	da
Beck Depression Inventory		27.25 (11.89)		27.30 (7.86)	0.02	0.99	< 0.01
Altman Mania Rating Scale		2.40 (2.76)		2.15 (2.23)	3.15	0.75	0.10
STAI-Sb		45.95 (13.57)		42.35 (10.04)	0.95	0.35	0.30
Beck Suicide Scale–worst everc		8.30 (1.78)		5.80 (2.65)	3.50	0.01	1.11
Barratt Impulsiveness Scale		71.70 (8.10)		65.90 (8.64)	2.19	0.04	0.69
Age at onset of disorder, years		17.35 (6.75)		22.15 (9.42)	1.77	0.08	0.59
Number of hospitalizations		2.65 (4.49)		0.30 (0.92)	2.29	0.03	0.73
Number of suicide attempts		1.15 (1.09)		0.70 (1.30)	1.18	0.24	0.38
	n		n		χ2(1)
Comorbid anxiety disorder	12	0.85 (0.81)	6	0.30 (0.47)	3.63	0.11
Number of episodes of depression					6.30	0.11
1–5	3	4.00 (1.00)	10	2.90 (1.37)
6–10	2	7.00 (1.41)	0	0.00 (0.00)
11–20	1	16.00 (0.00)	2	15.50 (6.36)
Too many to count	9	–	2	–
Number of episodes of (hypo)mania
1–5	4	3.25 (0.96)
6–10	1	8.00 (0.00)
11–20	4	18.25 (5.38)
Too many to count	5	–

STAI-S = Spielberger State-Trait Anxiety Inventory–State version.

^aCohen's d is a standardized measure of effect size in which values between 0.2 and 0.3 are taken to indicate small effect, values around 0.5 indicate a medium effect, and values ≥ 0.8 indicate a large effect (41).

^bRating of anxiety level in research session.

^cScreening score.