Am J Psychiatry 1992; 149:904-908
Copyright © 1992 by American Psychiatric Association
Long-term study of the sleep of insomnia patients with sleep state misperception and other insomnia patients
RJ Salin-Pascual, TA Roehrs, LA Merlotti, F Zorick and T Roth
Sleep Disorders Center, Henry Ford Hospital, Detroit, MI 48202-2689.
OBJECTIVE: The objectives were 1) to investigate differences among patients
with subjective insomnia (sleep state misperception), patients with
objective findings of insomnia, and normal volunteers and 2) to assess the
consistency of the sleep findings during a 2-month period. METHOD:
Twenty-one subjects were studied. Subjects with sleep state misperception
(N = 7) had insomnia complaints for more than 1 year, no objective sleep
disturbance, and sleep efficiency of 90% or greater (on the diagnostic
screening sleep recording), while subjectively estimating that sleep time
was less than 6.5 hours. Subjects with objective insomnia (N = 7) met the
same subjective criteria, but objectively sleep efficiency was 85% or less.
Normal subjects (N = 7) had no insomnia complaints and objective sleep
efficiency of 90% or greater. All subjects were recorded on 2 consecutive
nights three times with a 3-week period between each pair of nights (6
standard all-night polysomnographic sessions of 8 hours). A subjective
sleep questionnaire was administered after each sleep recording night.
RESULTS: Sleep stage variables (percentages) were similar between the two
insomnia groups, and both were different from the normal subjects. Sleep
continuity variables were disturbed in the objective insomnia group, but
they were similar in the sleep state misperception and normal groups. Both
insomnia groups rated their sleep as inadequate on the questionnaires and
differed from the normal subjects. The distinct sleep patterns of each of
the three groups did not vary over the 6 nights of assessment. CONCLUSIONS:
Sleep state misperception may be a prodromic or transitional state of sleep
dysfunction between normal sleep and the sleep pattern of objective
insomnia.
