Treatment of Obstructive Sleep Apnea may be an Important Adjunct to Therapy of Posttraumatic Stress Disorder not to be Overlooked

The influence of sleep on fear extinction in trauma-related disorders

In Posttraumatic Stress Disorder (PTSD), fear and anxiety become dysregulated following psychologically traumatic events. Regulation of fear and anxiety involves both high-level cognitive processes such as cognitive reattribution and low-level, partially automatic memory processes such as fear extinction, safety learning and habituation. These latter processes are believed to be deficient in PTSD. While insomnia and nightmares are characteristic symptoms of existing PTSD, abundant recent evidence suggests that sleep disruption prior to and acute sleep disturbance following traumatic events both can predispose an individual to develop PTSD. Sleep promotes consolidation in multiple memory systems and is believed to also do so for low-level emotion-regulatory memory processes. Consequently sleep disruption may contribute to the etiology of PTSD by interfering with consolidation in low-level emotion-regulatory memory systems. During the first weeks following a traumatic event, when in the course of everyday life resilient individuals begin to acquire and consolidate these low-level emotion-regulatory memories, those who will develop PTSD symptoms may fail to do so. This deficit may, in part, result from alterations of sleep that interfere with their consolidation, such as REM fragmentation, that have also been found to presage later PTSD symptoms. Here, sleep disruption in PTSD as well as fear extinction, safety learning and habituation and their known alterations in PTSD are first briefly reviewed. Then neural processes that occur during the early post-trauma period that might impede low-level emotion regulatory processes through alterations of sleep quality and physiology will be considered. Lastly, recent neuroimaging evidence from a fear conditioning and extinction paradigm in patient groups and their controls will be considered along with one possible neural process that may contribute to a vulnerability to PTSD following trauma.

Response to Cognitive Processing Therapy in Veterans With and Without Obstructive Sleep Apnea

Recent studies have called attention to the need for enhancing treatment outcome in trauma-focused psychotherapies, such as cognitive processing therapy (CPT), with veterans. Given the prevalence of posttraumatic-related sleep disturbances, and the role of sleep in emotional learning and processing, sleep quality may be a target for improving CPT outcome. Elevated rates of obstructive sleep apnea (OSA) have been reported in samples of veterans with posttraumatic stress disorder (PTSD); however, the impact of OSA on response to CPT is unclear. In this study, CPT outcome was examined in veterans with and without a diagnosis of OSA. Following chart review, 68 OSA-positive and 276 OSA-negative veterans were identified. Generalized estimating equations were used to compare between-group differences in weekly self-reported PTSD symptomatology. The OSA-positive veterans reported greater PTSD severity over the course of treatment and at posttreatment compared with veterans without OSA (B = -0.657). Additionally, OSA-positive veterans with access to continuous positive airway pressure (CPAP) therapy reported less PTSD severity relative to OSA-positive veterans without access to CPAP (B = -0.421). Apnea appears to be a contributing factor to the reduced effectiveness of evidence-based psychotherapy for veterans with PTSD; however, preliminary evidence indicates that CPAP therapy may help mitigate the impact of OSA on treatment outcome.

Obstructive sleep apnea in combat-related posttraumatic stress disorder: a controlled polysomnography study

BACKGROUND

Obstructive sleep apnea (OSA) may be highly prevalent in posttraumatic stress disorder (PTSD) and may exacerbate PTSD complaints.

OBJECTIVE

Our objective was to determine whether the prevalence of OSA was high in a sample of Dutch veterans with PTSD as compared to age- and trauma-matched controls, and whether OSA was associated with more severe PTSD complaints.

METHODS

We determined the apnea hypopnea indices (AHI) with polysomnographic registrations in 20 veterans with PTSD, 24 veterans without PTSD, and 17 healthy controls. PTSD severity and nightmare complaints were assessed with the Clinician-Administered PTSD Scale (CAPS).

RESULTS

The prevalence of an AHI>10 was 29% in PTSD, 21% in trauma controls, and 29% in healthy controls (χ(2)= 0.60, df=2, p=n.s.). The mean CAPS score in patients with OSA (n=6) was significantly higher than in patients without OSA (p<0.05), while nightmare severity was similar in PTSD patients with OSA as compared to PTSD patients without OSA (p=n.s.). Furthermore, there was a significant correlation between AHI and CAPS score in PTSD patients (r=0.46, p<0.05, df=14).

CONCLUSIONS

Our results indicate that PTSD is not necessarily associated with a higher prevalence of OSA. However, PTSD severity was related to OSA, which may possibly mean that comorbid OSA leads to an increase in PTSD complaints. However, future research should indicate whether OSA exerts a negative influence on PTSD, and treatment of OSA alleviates PTSD symptoms.