Comorbidity between sleep apnea and insomnia.

The association between insomnia and sleep apnea has received little attention from health professionals in the past few decades. However, recent studies have shown a high prevalence of insomnia complaints in patients with objectively diagnosed obstructive sleep apnea (OSA) syndrome. In this paper we have reviewed data published on different aspects of this association: the clinical profile of sleep-disordered breathing (SDB)-plus, the nature of the association, the role in the onset of insomnia played by OSA itself and other comorbidity factors such as depression or the restless leg syndrome.