Purpose: A high prevalence of depressive symptomatology
has been reported amongst sufferers of obstructive sleep
apnea (OSA), but it remains unclear as to whether this is
due to their OSA or other factors associated with the
disorder. The current study aimed to assess the incidence
and aetiology of depression in a community sample of
individuals presenting to the sleep laboratory for diagnostic
assessment of OSA.
Methods: Forty-five consecutive individuals who presented to
the sleep laboratory were recruited; of those, 34 were
diagnosed with OSA, and 11 were primary snorers with no
clinical or laboratory features of OSA. Nineteen control
subjects were also recruited. Patients and controls completed
the Beck Depression Inventory, the Profile of Mood States
(POMS), and the Epworth Sleepiness Scale to assess their
mood and sleepiness, prior to their polysomnography.
Results: All patients reported significantly more depressive
symptoms compared with healthy controls, regardless of their degree of OSA. There were no significant differences
between OSA patients and primary snorers on any of the
mood and self-rated sleepiness measures. Depression scores
were not significantly associated with any of the nocturnal
variables. Regression analysis revealed that the POMS
fatigue subscale explained the majority of the variance in
subjects' depression scores.
Conclusions: Fatigue was the primary predictor of the level
of depressive symptoms in patients who attended the sleep
laboratory, regardless of the level of severity of sleep disordered breathing. When considering treatment options,
practitioners should be aware of the concomitant occurrence
of depressive symptoms and fatigue in patients presenting with sleep complaints, which may not be due
to a sleep disorder
