Table 2.

Z-scores of neurocognitive performances in chronic insomniacs compared among insomniacs using benzodiazepine group, drug-free insomniacs, and controls

		Insomniacs using benzodiazepine (a)	Drug-free insomniacs (b)	Controls (c)	F	p	Post hoc
		N=29	N=27	N=28
Global cognition
	Mini-Mental State Examination	-0.18±1.01	0.45±0.75	0.24±1.00	2.73	0.072
Attention/concentration
	Digit span backward	0.16±1.30	0.61±1.25	0.51±1.13	2.68	0.075
Memory
	Word list recognition	-0.14±0.89	0.07±0.7	0.12±0.68	0.18	0.833
	Word list recall	-0.07±0.92	0.29±1.04	0.47±1.02	0.82	0.447
	Recall of constructional praxis	0.08±1.03	0.28±0.81	0.35±1.06	1.67	0.195
Executive function
	Trail making test digit symbol test A	0.73±0.66	1.27±0.38	1.09±0.47	10.2	<0.001	a<b, a<c
	Categorical fluency	-0.01±0.99	1.26±0.97	0.77±1.08	4.32	0.002	a<b
	Frontal assessment battery	0.28±0.70	0.56±0.69	0.25±0.80	2.34	0.104
	Constructional praxis	0.20±0.65	0.36±0.43	0.25±0.69	0.23	0.796
Visuospatial abilities
	Clock drawing	0.08±0.85	0.28±0.50	0.33±0.52	1.60	0.209

Data are presented as mean±standard deviation. Multivariable analysis of covariance after adjusting for confounders (including Epworth sleepiness scale and Beck Depression Inventory, and exposure of other psychotropics) and Bonferroni’s correction for multiple comparisons (p<0.005=0.05/10) were conducted