ABSTRACT
Standard psychiatric classification (DSM-IV-TR) traditionally attributes post-traumatic
sleep disturbance to a secondary or symptomatic feature of a primary psychiatric disorder.
The DSM-IV-TR paradigm, however, has not been validated with objective sleep assessment
technology, incorporated nosological constructs from the field of sleep disorders
medicine, or adequately addressed the potential for post-traumatic stress disorder
(PTSD) sleep problems to manifest as primary, physical disorders, requiring independent
medical assessments and therapies. This paradigm may limit understanding of sleep
problems in PTSD by promulgating such terms as ``insomnia related to another mental
disorder,'' a.k.a. ``psychiatric insomnia.'' Emerging evidence invites a broader comorbidity
perspective, based on recent findings that post-traumatic sleep disturbance frequently
manifests with the combination of insomnia and a higher-than-expected prevalence of
sleep-disordered breathing (SDB). In this model of complex sleep disturbance, the
underlying sleep pathophysiology interacts with PTSD and related psychiatric distress;
and this relationship appears very important as demonstrated by improvement in insomnia,
nightmares, and post-traumatic stress with successful SDB treatment, independent of
psychiatric interventions. Continuous positive airway pressure treatment in PTSD patients
with SDB reduced electroencephalographic arousals and sleep fragmentation, which are
usually attributed to central nervous system or psychophysiological processes. Related
findings and clinical experience suggest that other types of chronic insomnia may
also be related to SDB. We hypothesize that an arousal-based mechanism, perhaps initiated
by post-traumatic stress and/or chronic insomnia, may promote the development of SDB
in a trauma survivor and perhaps other patients with chronic insomnia. We discuss
potential neurohormonal pathways and neuroanatomatical sites that may be involved
in this proposed interaction between insomnia and SDB.
KEYWORD
Sleep-disordered breathing - insomnia - obstructive sleep apnea - upper airway resistance
syndrome - post-traumatic stress disorder - sleep fragmentation
