Table 1.

Participant Characteristics

Characteristic	Placebo n = 41		0.1mg n = 41		0.5mg n = 41		p-Value*
	mean	SD	mean	SD	mean	SD
Age (y)	80.5	4.0	80.0	4.0	80.1	4.0	0.824
Sex (% male)	58.5%		53.7%		56.1%		0.906
Education (y)	17.0	2.5	16.2	2.5	16.2	2.7	0.265
Weight (lbs)	165.2	31.7	177.3	34.1	164.4	37.7	0.168
Geriatric Depression Scale	1.1	1.3	1.1	1.4	1.3	1.5	0.834
Epworth Sleepiness Scale	6.8	3.3	6.0	3.3	5.0	2.7	0.032
Cognitive Status
MMSE	29.5	0.7	29.3	1.2	29.6	0.6	0.418
Logical Memory 1	13.2	3.9	13.0	4.1	11.9	4.0	0.247
Logical Memory 2	11.9	4.3	11.5	3.8	10.5	4.0	0.279
WAIS - Vocabulary	52.9	7.8	48.4	11.0	52.0	11.7	0.116
WAIS - Block Design	30.3	11.7	28.1	8.8	29.5	7.6	0.581
Executive Function Measures
Spatial Working Memory	43.9	16.0	46.5	15.5	42.2	16.9	0.477
Stockings of Cambridge	4.3	2.3	4.2	2.5	4.0	2.1	0.875
ID/ED Shift	11.9	10.3	11.8	10.2	11.9	10.3	0.997
Paired Associates Learning	11.3	3.9	12.6	4.4	12.7	4.7	0.245
Stroop Color Word	30.2	8.2	29.9	9.0	30.5	9.5	0.952
Trail Making Test B	94.4	35.6	106.4	48.8	88.8	32.0	0.122
Quality of Life
SF-36-PCS	48.3	6.9	46.4	8.8	48.1	8.3	0.525
SF-36-MCS	56.0	5.7	56.1	6.9	55.5	6.6	0.920

Notes: MMSE = Mini-Mental State Examination; ID/ED Shift = Intradimensional/Extradimensional Shift; SF-36-MCS and SF-36-PCS = Mental Component Score and Physical Component Score of the 36-Item Short-Form Health Survey

^*p-Values are for ANOVA for continuous variables and chi-square for categorical variables and are uncorrected for multiplicity.