The effect of continuous positive air pressure (CPAP) on nightmares in patients with posttraumatic stress disorder...

Post-Traumatic Stress Disorder (PTSD) is increasingly prevalent among Veterans characterized by recurrent nightmare and disrupted sleep. Veterans with PTSD also have a high prevalence of obstructive sleep apnea (OSA) and untreated OSA worsens the sleep-related symptoms of PTSD. In our study, we hypothesized that among PTSD-afflicted Veterans with OSA, CPAP therapy may reduce the frequency of nightmares and a better CPAP compliance may be associated with increased symptom improvement.

We retrospectively reviewed medical records to identify OSA patients treated in a VA medical center who also carried a diagnosis of PTSD (n = 69). Data about patient characteristics and polysomnographic findings were extracted. Repeated-measures t-tests were performed, comparing mean nightmare frequency and Epworth sleepiness score (ESS) before and after CPAP treatment. Multiple linear regressions were done to identify factors predicting CPAP compliance. A logistic regression analysis was also done to estimate the odds of subjective improvement in PTSD symptoms with CPAP.

CPAP therapy reduced the mean ESS from 14.62 to 8.52 (p < 0.001) and the mean number of nightmares per week from 10.32 to 5.26 (p < 0.01). Reduced nightmare frequency after CPAP treatment was best predicted by CPAP compliance (p < 0.001). Every 10% increase in CPAP compliance almost doubled the odds of benefitting by CPAP (odds ratio = 1.92, 95% CI = 1.47-2.5).

In Veterans with PTSD and OSA, CPAP therapy reduces PTSD-associated nightmares and improves overall PTSD symptoms. We recommend that all PTSD patients should be screened clinically for symptoms of OSA and receive CPAP treatment whenever possible to improve PTSD symptoms.