Effects of early nightmares on the development of sleep disturbances in motor vehicle accident victims
ABSTRACT The present study prospectively examined the extent to which trauma-related nightmares affected the subsequent development of insomnia symptoms in 314 motor vehicle accident (MVA) victims. Participants were assessed in-hospital and at 2 weeks, 6 weeks, 3 months, and 1 year post-MVA. Hierarchical linear regression analyses showed that 6-week PTSD symptoms (PTSS) and 3-month nightmares, but not 2-week nightmares were positively associated with sleep onset and maintenance problems reported at 3-month post-MVA. Nightmares reported at 3-months post-MVA were positively associated with 1-year sleep maintenance problems. These findings highlight the dynamic relationship between PTSS and sleep problems as well as the potential importance of early intervention for trauma-related nightmares as a means to prevent sleep problems after a traumatic experience.
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ABSTRACT: Objective: Sleep disturbances, including trouble falling and remaining asleep and recurrent nightmares, are symptoms of posttraumatic stress. A growing body of literature indicates that sleep disturbance may also convey vulnerability for the continuation of other symptoms of posttraumatic stress, including fear, anxiety, and heightened arousal. However, longitudinal research, which could help understand how these relationships unfold over time, has been limited. Method: The longitudinal relationships between sleep disturbance and posttraumatic stress were investigated in 779 Palestinian adults randomly selected and interviewed twice during the period from April 2008 to November 2008, amid ongoing violent political turmoil. The recruitment method produced a representative sample and excellent retention. Cross-panel structural equation modeling was used to examine relationships between sleep and distress across two study periods. Results: Results indicated that initial sleep problems were associated with increased posttraumatic stress disorder (PTSD), depression, and intrapersonal resource loss at follow-up 6 months later, but initial PTSD, depression, and intrapersonal resource loss were not associated with increased sleep problems at follow-up. Conclusions: Sleep problems may confer vulnerability to longer-term distress in the presence of ongoing political violence. Future research should examine whether interventions targeting trauma-related sleep problems may improve prevention and treatment for PTSD and related disorders. (PsycINFO Database Record (c) 2013 APA, all rights reserved).Health Psychology 05/2013; 33(4). DOI:10.1037/a0032572 · 3.95 Impact Factor
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ABSTRACT: Sleep facilitates the consolidation of fear extinction memory. Nightmares and insomnia are hallmark symptoms of posttraumatic stress disorder (PTSD), possibly interfering with fear extinction and compromising recovery. A perpetual circle may develop when sleep disturbances increase the risk for PTSD and vice versa. To date, therapeutic options for alleviating sleep disturbances in PTSD are limited. WE CONDUCTED THREE STUDIES TO EXAMINE THE RELATIONSHIP BETWEEN SLEEP AND POSTTRAUMATIC SYMPTOMS: (1) a prospective longitudinal cohort study examining the impact of pre-deployment insomnia symptoms and nightmares on the development of PTSD; (2) a cross-sectional study examining subjective sleep measures, polysomnography, endocrinological parameters, and memory in veterans with PTSD, veterans without PTSD, and healthy controls (HCs); (3) a randomized controlled trial (RCT) (n=14) comparing the effect of prazosin and placebo on sleep disturbances in veterans with PTSD. In addition to these studies, we systematically reviewed the literature on treatment options for sleep disturbances in PTSD. Pre-deployment nightmares predicted PTSD symptoms at 6 months post-deployment; however, insomnia symptoms did not. Furthermore, in patients with PTSD, a correlation between the apnea index and PTSD severity was observed, while obstructive sleep apnea syndrome was not more prevalent. We observed a significant increase in awakenings during sleep in patients with PTSD, which were positively correlated with adrenocorticotropic hormone (ACTH) levels, negatively correlated with growth hormone (GH) secretion, and the subjective perception of sleep depth. Also, heart rate was significantly increased in PTSD patients. Interestingly, plasma levels of GH during the night were decreased in PTSD. Furthermore, GH secretion and awakenings were independent predictors for delayed recall, which was lower in PTSD. In our RCT, prazosin was not associated with improvement of any subjective and objective sleep parameters. Only a few RCTs have been published. They show promising results for atypical antipsychotics and prazosin, the latter especially on nightmare reduction. Disturbed sleep due to nightmares increases the risk for PTSD. PTSD in turn leads to increased sleep fragmentation, decreased GH secretion, and frequent nightmares, which may again compromise fear extinction, synaptic plasticity, and recovery. This suggests that disturbed sleep is a precipitating and perpetuating factor in PTSD symptomatology, creating a perpetual circle. This dissertation suggests that activity of the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system (SNS) is involved in disturbed sleep in patients with PTSD.European Journal of Psychotraumatology 10/2012; 3. DOI:10.3402/ejpt.v3i0.19142 · 2.40 Impact Factor
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ABSTRACT: Presents a new approach to a near optimum MTI filter design using adaptive techniques. The resulting scheme consists of an adaptive whitening filter for radar clutter followed by a likelihood ratio test (LRT) for target signal in white noise. A complete procedure is developed for the whitening filter design. The LRT may operate either with or without a clutter power map. The detection performance of the new scheme is evaluated using real radar data. When operating with a clutter map, it provides 7.5 dB average performance improvement over the innovations-based detection algorithm (IBDA) for ground clutter-dominated data and 5 dB improvement for weather clutter. And the latter has been demonstrated to be superior to the classical moving-target-detection (MTD) by 3 to 5 dBAcoustics, Speech, and Signal Processing, 1988. ICASSP-88., 1988 International Conference on; 05/1988