Self-reported sleep lengths = 9 hours among Swedish patients with stress-related exhaustion:
Associations with depression, quality of sleep and levels of fatigue
Sammanfattning
Background: Insomnia-type sleep disturbances are frequent among patients suffering from stress-
related exhaustion disorder. However, clinical observations indicate that a subgroup suffer from
sleep lengths frequently exceeding 9 hours, coupled with great daytime sleepiness. Aims: The aim of
the present study was to investigate differences in socio-demographic variables, use of medications,
sleep parameters, anxiety, depression and fatigue, between individuals with varying sleep lengths,
in a sample of 420 Swedish patients (mean age 42 ± 9 years; 77% women) referred to treatment for
exhaustion disorder. Patients were allocated to the groups: "never/seldom = 9 hours" (n = 248),
"sometimes = 9 hours" (n = 115) and "mostly/always = 9 hours" (n = 57), based on their self-rated
frequency of sleep lengths = 9 hours. Methods: The design was cross-sectional and data was
collected by means of questionnaires at pre-treatment. Results: Univariate analyses showed that
patients in the "mostly/always = 9 hours" group were more often on sick leave, and reported more
depression and fatigue, better sleep quality and more daytime sleepiness, than patients in the other
groups. Multivariate analyses showed that these patients scored higher on measures of fatigue than
the rest of the sample independently of gender, use of antidepressants, sick leave, depression and
quality of sleep. Conclusions: Patients suffering from exhaustion disorder and reporting excessive
sleep seem to have a generally poorer clinical picture but better quality of sleep than their
counterparts with shorter sleep lengths. The mechanisms underlying these differences, together with
their prognostic value and implications for treatment remain to be elucidated in future studies