Faculty Bibliography

BACKGROUND: Nightmares and insomnia are experienced by 70% of patients suffering from post-traumatic stress disorder (PTSD). These sleep problems are often resistant to treatment and exert a strong negative influence on the quality of life. In the last few decades several studies have reported on the characteristics of sleep disturbances in PTSD. AIM: To provide an overview of objective features of sleep disturbances - as opposed to self-report methods - in patients with PTSD. METHOD: Articles on this topic, published in peer-reviewed journals between 1980 and the present, were retrieved from Medline and Embase, using the search terms 'PTSD', 'sleep', 'nightmares', 'insomnia', 'polysomnography'. RESULTS: Studies reported on changes in sleep efficiency, arousal regulation, motor activity during sleep, rem characteristics and delta sleep activity during sleep. Also, correlations were found between nightmares and sleep apnoea in ptsd. In some studies on sleep disturbance no objective sleep disturbances were found in PTSD patients. However, most studies on PTSD related sleep disturbances were conducted in small, heterogeneous groups, and results were therefore inconsistent. Even the results of larger and more homogeneous studies were sometimes contradictory. CONCLUSION: There is a discrepancy between the clinical importance of sleep problems in PTSD and unambiguous objective sleep disorders. Future research should try to establish objective criteria for identifying the altered sleep patterns in PTSD. These criteria should help us to understand the neurobiological mechanisms of sleep disturbances in PTSD and develop new treatment strategies.

Posttraumatic stress disorder (PTSD) is typically accompanied by acute and chronic alterations in the stress response. These alterations have mostly been described in individuals under baseline conditions, but several studies have also used a challenge model to further assess the role of the hypothalamic-pituitary-adrenal (HPA) axis in the stress response. This paper reviews common methodology and research findings on HPA function in PTSD, and discusses the pathophysiological mechanisms underlying these findings. We reviewed the literature and selected all English-language, human subject, data driven, pharmacological and non-pharmacological challenge studies pertaining to the HPA axis, and in vitro leukocyte glucocorticoid receptor studies in adult PTSD subjects. Studies using a non-pharmacological stress paradigm (cognitive stress, trauma reminders) to stimulate the HPA axis showed an exaggerated cortisol response in PTSD. The most widely used pharmacological challenge with consistent results was the low dose dexamethasone-suppression test (DST). These DST studies showed enhanced cortisol suppression in subjects with PTSD. Different hypotheses have been purported to explain the alterations in HPA axis functioning in PTSD. The results of the reviewed challenge tests, however, did not exclusively support one of the hypothesized mechanisms. Further research assessing hormones at all levels of the HPA axis at both baseline and at challenge conditions with a proper stratification of study population, will be necessary for a better understanding of stress-responsivity on the level of the HPA axis in PTSD.