N. Kajimura et al., A POLYSOMNOGRAPHIC STUDY OF SLEEP PATTERNS IN NORMAL HUMANS WITH LOW-ANXIETY OR HIGH-ANXIETY PERSONALITY-TRAITS, PSYCHIATRY AND CLINICAL NEUROSCIENCES, 52(3), 1998, pp. 317-320
To clarify the effects of anxiety-related personality traits on sleep
patterns, polysomnographic examinations (PSG) were performed over 4 co
nsecutive nights on normal humans who tested within the low- or high-a
nxiety ranges. The subjects consisted of two groups of six male univer
sity students who scored either less than 45 points (low-anxiety group
) or more than 55 points (high-anxiety group) on the Spielberger's Sta
te Trait Anxiety Inventory. Compared to the levels of sleep change in
the high-anxiety group, the low-anxiety group exhibited a greater chan
ge in REM sleep and stage 2 sleep. The REM sleep in the low-anxiety gr
oup was shorter on the first and second nights compared to the third a
nd fourth nights, and the stage 2 sleep was longer on the first night
than on the remaining three nights. Thus, the low-anxiety group showed
a first-night effect followed by partial recovery on the second night
, while the high-anxiety group exhibited no obvious first-night effect
. These results suggest that there is a difference in sleep patterns,
assessed by consecutive PSG, between those with low- and high-anxiety
traits, and that anxiety-related personality traits attenuate the occu
rrence of the first-night effect, reflecting a lower adaptability to a
novel environment.