Differences in course of illness between patients with bipolar II disorder with and without epileptiform discharges or other sharp activity on electroencephalograms: a cross-sectional study

Table 2 Course of illness among participants with and without epileptiform discharges or other sharp activity

	ED/SA+ (n = 12)	ED/SA- (n = 74)	p-value
Age at onset			0.95^†
mean ± SD	19 ± 13	18 ± 11
median (IQR)	15 (3.5)	15 (7.8)
Depressive episodes per year			0.25^†
mean ± SD	0.60 ± 0.45	1.1 ± 1.4
median (IQR)	0.51 (0.72)	0.63 (0.78)
Hypomanic episodes per year			0.0090^†
mean ± SD	3.0 ± 3.2	1.6 ± 3.5
median (IQR)	1.5 (3.2)	0.61 (1.1)
Hypomania:depression ratio			0.00091^†
mean ± SD	9.7 ± 11	1.9 ± 4.7
median (IQR)	3.2 (16)	1.0 (1.0)
Admissions per decade^a			0.31^†
mean (SD)	0.81 (1.5)	1.2 (1.9)
median (IQR)	0.44 (0.76)	0.63 (1.4)
Rapid cycling, n (%)^b	6 (60)	27 (36)	0.18^‡

Abbreviations: ED epileptiform discharges, SA other sharp activity, IQR interquartile range, SD standard deviation. Missing data: ^a 1 in ED/SA+ group, ^b 2 in ED/SA+ group. Tests: † Wilcoxon rank sum test, ‡ Fisher’s exact test

ISSN: 1471-244X