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Biomedical subjects

Thomas C Neylan

Publications and source records attributed to Thomas C Neylan.

26 records · Page 2Linked to original sources
PubMed2003

Delta sleep response to metyrapone in post-traumatic stress disorder.

Metyrapone blocks cortisol synthesis, which results in the stimulation of hypothalamic cortiocotropin-releasing factor (CRF) and a reduction in delta sleep. We examined the effect of metyrapone administration on endocrine and sleep measures in male subjects with and without chronic PTSD. We hypothesized that metyrapone would result in a decrease in delta sleep and that the magnitude of this decrease would be correlated with the endocrine response. Finally, we utilized the delta sleep response to metyrapone as an indirect measure of hypothalamic CRF activity and hypothesized that PTSD subjects would have decreased delta sleep at baseline and a greater decrease in delta sleep induced by metyrapone. Three nights of polysomnography were obtained in 24 male subjects with combat-related PTSD and 18 male combat-exposed normal controls. On day 3, metyrapone was administered during normal waking hours until habitual sleep onset preceding night 3. Endocrine responses to metyrapone were measured in plasma obtained the morning following sleep recordings, the day before and after administration. Repeated measures ANOVAs were conducted to compare the endocrine and sleep response to metyrapone in PTSD and controls. PTSD subjects had significantly less delta sleep as indexed by stages 3 and 4, and total delta integrated amplitude prior to metyrapone administration. There were no differences in premetyrapone cortisol or ACTH levels in PTSD vs controls. PTSD subjects had a significantly decreased ACTH response to metyrapone compared to controls. Metyrapone caused an increase in awakenings and a marked decrease in quantitative measures of delta sleep that was significantly greater in controls compared to PTSD. The decline in delta sleep was significantly associated with the magnitude of increase in both 11-deoxycortisol and ACTH. The results suggest that the delta sleep response to metyrapone is a measure of the brain response to increases in hypothalamic CRF. These data also suggest that the ACTH and sleep EEG response to hypothalamic CRF is decreased in PTSD.

Adrenocorticotropic Hormone↗
PubMed2003

Temporal instability of auditory and visual event-related potentials in posttraumatic stress disorder.

BACKGROUND: We examined P300 measures in patients with posttraumatic stress disorder (PTSD) and control subjects at two different time points to determine event-related potential (ERP) stability over time and the relationship of changes in ERPs to changes in symptom levels. METHODS: Auditory and visual P300 was recorded in a three-condition novelty oddball task in 25 male subjects with combat-related PTSD and 15 male combat-exposed normal control subjects at two time points separated by 6-12 months. Regression analyses were conducted to compare the temporal stability of ERP measures in PTSD and control subjects. Variability in ERP measures over time within PTSD subjects was examined for association with changes in symptom levels. RESULTS: There were no significant differences in P300 amplitude or latency in PTSD versus control subjects at either time point, regardless of stimulus type (target, novel) or modality (auditory, visual). Nine of 24 P300 measures were significantly less predictable over time in the PTSD group compared to control subjects. Variability of P300 measures over time was not associated with fluctuations in symptoms of depression or PTSD. CONCLUSIONS: P300 ERPs are more variable cross-sectionally and over time in PTSD subjects compared to trauma exposed control subjects. Measures of variability about the group mean appear to be more informative about the cognitive electrophysiology of PTSD than measures of central tendency.

Acoustic Stimulation↗
PubMed2003

Fear-potentiated startle and posttraumatic stress symptoms in urban police officers.

We studied the effects of increasing threat conditions on self-reported emotion, eyeblink electromyogram, and skin conductance responses to startling sounds in 55 police officers who endorsed a range of PTSD (posttraumatic stress disorder) symptoms. We found that contextual threat affected both physiologic and self-reported emotional responses. Greater PTSD symptom severity was related to greater physiologic responses under the low and medium but not under the high threat condition. The relationship between PTSD symptoms and physiologic responses was neither explained by self-reported emotional responses nor preexisting reported exaggerated startle symptoms. Our results emphasize the importance of contextual threat and suggest that laboratory measures of startle improve upon self-reported exaggerated startle alone in indexing PTSD symptom severity in urban police officers.

Adult↗
PubMed2003

The effect of nefazodone on subjective and objective sleep quality in posttraumatic stress disorder.

BACKGROUND: This study assesses the efficacy of nefazodone treatment (target dose of 400-600 mg/day) on objective and subjective sleep quality in Vietnam combat veterans with chronic DSM-IV posttraumatic stress disorder (PTSD). METHOD: Medically healthy male Vietnam theater combat veterans with DSM-IV PTSD (N = 10) completed a 12-week open-label trial. Two nights of ambulatory polysomnography were obtained at baseline and at the end of the trial. PTSD and depressive symptoms and subjective sleep quality were assessed at baseline and after 12 weeks. Data were collected in 1999 and 2000. RESULTS: Nefazodone treatment led to a significant decrease in PTSD and depressive symptoms (p <.05), an improvement in global subjective sleep quality, and a reduction in nightmares. Nefazodone also resulted in a substantial improvement in objective measures of sleep quality, particularly increased total sleep time, sleep maintenance, and delta sleep as measured by period amplitude analysis. CONCLUSION: Nefazodone therapy results in an improvement of both subjective and objective sleep quality in subjects with combat-related PTSD.

Antidepressive Agents, Second-Generation↗
PubMed2002

New directions in the pharmacotherapy of posttraumatic stress disorder.

Advances in psychopharmacology of PTSD are presented, focusing on antidepressants, adrenergic agents, antianxiety agents, and mood stabilizers. Treatment recommendations are related to recent advances in the understanding of the biology of PTSD. Pharmacotherapy of PTSD in children and adolescents is discussed, including recommended dose ranges. Recommendations are specified for pharmacotherapy of trauma survivors in the immediate aftermath of traumatic exposure, and for those with acute and chronic posttraumatic stress disorders.

Acute Disease↗
PubMedDate not supplied

Critical incident exposure and sleep quality in police officers.

OBJECTIVE: Police officers face many stressors that may negatively impact sleep quality. This study compares subjective sleep quality in police officers with that in control subjects not involved in police or emergency services. We examined the effects of critical incident exposure (trauma exposure) and routine (nontraumatic) work environment stressors on sleep quality after controlling for the effects of work shift schedule. METHODS: Subjective sleep disturbances were measured by the Pittsburgh Sleep Quality Index in police officers (variable-shift workers, N = 551; stable day-shift workers, N = 182) and peer-nominated comparison subjects (variable-shift workers, N = 98; stable day-shift workers, N = 232). The main predictor variables were 1) duty-related critical incident exposure to on-line policing and 2) work environment stress related to routine administrative and organizational aspects of police work. RESULTS: Police officers on both variable and stable day shifts reported significantly worse sleep quality and less average sleep time than the two corresponding control groups. Within police officers, cumulative critical incident exposure was associated with nightmares but only weakly associated with poor global sleep quality. In contrast, the stress from officers' general work environment was strongly associated with poor global sleep quality. Sleep disturbances were strongly associated with posttraumatic stress symptoms and general psychopathology. CONCLUSIONS: A large percentage of police officers report disturbances in subjective sleep quality. Although the life-threatening aspects of police work are related to nightmares, the routine stressors of police service seem to most affect global sleep quality in these subjects. These findings may have implications for health and occupational performance.

Adult↗